Diphenhydramine

Generic name: Pronounced as (dye fen hye' dra meen)
Brand names
  • Aler-Dryl®
  • Allergia-C®
  • Allermax®
  • Altaryl®
  • Banophen®
  • Ben Tann®
  • Benadryl®
  • Bromanate AF®
  • Compoz Nighttime Sleep Aid®
  • Dicopanol®
  • Diphedryl®
  • Diphen®
  • Diphenadryl®
  • Diphenhist®
  • Diphenylin®
  • Dytan®
  • Hydramine®
  • Nytol®
  • Pardryl®
  • PediaCare Children's Allergy®
  • Siladryl®
  • Silphen®
  • Sominex®
  • Unisom®
Click on drug name to hear pronunciation

Medical Content Reviewed By HelloPharmacist Staff

Last Revised - 01/15/2022

Diphenhydramine is used to relieve red, irritated, itchy, watery eyes; sneezing; and runny nose caused by hay fever, allergies, or the common cold. Diphenhydramine is also used to relieve cough caused by minor throat or airway irritation. Diphenhydramine is also used to prevent and treat motion sickness, and to treat insomnia (difficulty falling asleep or staying asleep). Diphenhydramine is also used to control abnormal movements in people who have early stage parkinsonian syndrome (a disorder of the nervous system that causes difficulties with movement, muscle control, and balance) or who are experiencing movement problems as a side effect of a medication.

Diphenhydramine will relieve the symptoms of these conditions but will not treat the cause of the symptoms or speed recovery. Diphenhydramine should not be used to cause sleepiness in children. Diphenhydramine is in a class of medications called antihistamines. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms.

Diphenhydramine comes as a tablet, a rapidly disintegrating (dissolving) tablet, a capsule, a liquid-filled capsule, a dissolving strip, powder, and a liquid to take by mouth. When diphenhydramine is used for the relief of allergies, cold, and cough symptoms, it is usually taken every 4 to 6 hours. When diphenhydramine is used to treat motion sickness, it is usually taken 30 minutes before departure and, if needed, before meals and at bedtime. When diphenhydramine is used to treat insomnia it is taken at bedtime (30 minutes before planned sleep). When diphenhydramine is used to treat abnormal movements, it is usually taken three times a day at first and then taken 4 times a day. Follow the directions on the package or on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take diphenhydramine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor or directed on the label.

Diphenhydramine comes alone and in combination with pain relievers, fever reducers, and decongestants. Ask your doctor or pharmacist for advice on which product is best for your symptoms. Check nonprescription cough and cold product labels carefully before using two or more products at the same time. These products may contain the same active ingredient(s) and taking them together could cause you to receive an overdose. This is especially important if you will be giving cough and cold medications to a child.

Nonprescription cough and cold combination products, including products that contain diphenhydramine, can cause serious side effects or death in young children. Do not give these products to children younger than 4 years of age. If you give these products to children 4 to 11 years of age, use caution and follow the package directions carefully.

If you are giving diphenhydramine or a combination product that contains diphenhydramine to a child, read the package label carefully to be sure that it is the right product for a child of that age. Do not give diphenhydramine products that are made for adults to children.

Before you give a diphenhydramine product to a child, check the package label to find out how much medication the child should receive. Give the dose that matches the child's age on the chart. Ask the child's doctor if you don't know how much medication to give the child.

If you are taking the liquid, do not use a household spoon to measure your dose. Use the measuring spoon or cup that came with the medication or use a spoon made especially for measuring medication.

If you are taking the dissolving strips, place the strips on your tongue one at a time and swallow after they melt.

If you are taking the rapidly dissolving tablets, place a tablet on your tongue and close your mouth. The tablet will quickly dissolve and can be swallowed with or without water.

If you are taking the capsules, swallow them whole. Do not try to break the capsules.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking diphenhydramine,

  • tell your doctor and pharmacist if you are allergic to diphenhydramine, any other medications, or any of the ingredients in diphenhydramine preparations. Ask your doctor or pharmacist or check the package label for a list of the ingredients.

  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: other diphenhydramine products (even those that are used on the skin); other medications for colds, hay fever, or allergies; medications for anxiety, depression, or seizures; muscle relaxants; narcotic medications for pain; sedatives; sleeping pills; and tranquilizers.

  • tell your doctor if you have or have ever had asthma, emphysema, chronic bronchitis, or other types of lung disease; glaucoma (a condition in which increased pressure in the eye can lead to gradual loss of vision); ulcers; difficulty urinating (due to an enlarged prostate gland); heart disease; high blood pressure; seizures; or an overactive thyroid gland.If you will be using the liquid, tell your doctor if you have been told to follow a low-sodium diet.

  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking diphenhydramine, call your doctor.

  • you should know that generally diphenhydramine should not be used in older adults, except to manage serious allergic reactions, because it is not as safe or effective as other medication(s) to treat your condition. If you are 65 years of age or older, talk to your doctor about the risks and benefits of taking this medication.

  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking diphenhydramine.

  • you should know that this medication may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.

  • remember that alcohol can add to the drowsiness caused by this medication. Avoid alcoholic beverages while you are taking this medication.

  • if you have phenylketonuria (PKU, an inherited condition in which a special diet must be followed to prevent damage to your brain that can cause severe intellectual disability), you should know that some brands of chewable tablets and rapidly disintegrating tablets that contain diphenhydramine may be sweetened with aspartame, a source of phenylalanine.

Unless your doctor tells you otherwise, continue your normal diet.

Diphenhydramine is usually taken as needed. If your doctor has told you to take diphenhydramine regularly, take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

  • Diphenhydramine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

    • dry mouth, nose, and throat

    • drowsiness

    • dizziness

    • nausea

    • vomiting

    • loss of appetite

    • constipation

    • increased chest congestion

    • headache

    • muscle weakness

    • excitement (especially in children)

    • nervousness

  • Some side effects may be serious. If you experience any of the following symptoms, call your doctor immediately:

    • vision problems

    • difficulty urinating or painful urination

  • Diphenhydramine may cause other side effects. Call your doctor if you experience any unusual problems while you are taking this medication.

  • If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Ask your pharmacist any questions you have about diphenhydramine.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

  • Advil PM® (containing Diphenhydramine, Ibuprofen)
  • Alahist LQ® (containing Diphenhydramine, Phenylephrine)
  • Aldex CT® (containing Diphenhydramine, Phenylephrine)
  • Aleve PM® (containing Diphenhydramine, Naproxen)
  • Anacin P.M. Aspirin Free® (containing Acetaminophen, Diphenhydramine)
  • Bayer Aspirin PM® (containing Aspirin, Diphenhydramine)
  • Benadryl-D Allergy Plus Sinus® (containing Diphenhydramine, Phenylephrine)
  • Children's Dimetapp Nighttime Cold and Congestion® (containing Diphenhydramine, Phenylephrine)
  • Doans PM® (containing Diphenhydramine, Magnesium Salicylate)
  • Endal HD® (containing Diphenhydramine, Phenylephrine)
  • Excedrin PM® (containing Acetaminophen, Diphenhydramine)
  • Goody's PM® (containing Acetaminophen, Diphenhydramine)
  • Legatrin PM® (containing Acetaminophen, Diphenhydramine)
  • Masophen PM® (containing Acetaminophen, Diphenhydramine)
  • Midol PM® (containing Acetaminophen, Diphenhydramine)
  • Motrin PM® (containing Diphenhydramine, Ibuprofen)
  • PediaCare Children's Allergy and Cold® (containing Diphenhydramine, Phenylephrine)
  • Robitussin Night Time Cough and Cold® (containing Diphenhydramine, Phenylephrine)
  • Sudafed PE Day/Night Cold® (containing Acetaminophen, Dextromethorphan, Diphenhydramine, Guaifenesin, Phenylephrine)
  • Sudafed PE Day/Night Congestion® (containing Diphenhydramine, Phenylephrine)
  • Sudafed PE Severe Cold® (containing Acetaminophen, Diphenhydramine, Phenylephrine)
  • Tekral® (containing Diphenhydramine, Pseudoephedrine)
  • Theraflu Nighttime Severe Cold and Cough® (containing Acetaminophen, Diphenhydramine, Phenylephrine)
  • Triaminic Night Time Cold and Cough® (containing Diphenhydramine, Phenylephrine)
  • Tylenol Allergy Multi-Symptom Nighttime® (containing Acetaminophen, Diphenhydramine, Phenylephrine)
  • Tylenol Severe Allergy® (containing Acetaminophen, Diphenhydramine)
  • Unisom with Pain Relief® (containing Acetaminophen, Diphenhydramine)

Drug Interaction
Moxifloxacin Moxifloxacin The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Moxifloxacin.
Montelukast Montelukast The metabolism of Diphenhydramine can be decreased when combined with Montelukast.
Leflunomide Leflunomide The metabolism of Diphenhydramine can be decreased when combined with Leflunomide.
Delavirdine Delavirdine The metabolism of Diphenhydramine can be decreased when combined with Delavirdine.
Nevirapine Nevirapine The metabolism of Diphenhydramine can be decreased when combined with Nevirapine.
Dolasetron Dolasetron The risk or severity of adverse effects can be increased when Dolasetron is combined with Diphenhydramine.
Anagrelide Anagrelide The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Anagrelide.
Bisacodyl Bisacodyl The therapeutic efficacy of Bisacodyl can be decreased when used in combination with Diphenhydramine.
Candesartan Candesartan The metabolism of Diphenhydramine can be decreased when combined with Candesartan.
Cilostazol Cilostazol The metabolism of Cilostazol can be decreased when combined with Diphenhydramine.
Clopidogrel Clopidogrel The metabolism of Diphenhydramine can be decreased when combined with Clopidogrel.
Diphenoxylate Diphenoxylate The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Diphenoxylate.
Erythromycin and Sulfisoxazole Erythromycin and Sulfisoxazole The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Erythromycin.
Fenofibrate Fenofibrate The metabolism of Diphenhydramine can be decreased when combined with Fenofibrate.
Guanfacine Guanfacine The risk or severity of adverse effects can be increased when Guanfacine is combined with Diphenhydramine.
Magnesium Hydroxide Magnesium Hydroxide The therapeutic efficacy of Magnesium hydroxide can be decreased when used in combination with Diphenhydramine.
Magnesium Oxide Magnesium Oxide The therapeutic efficacy of Magnesium oxide can be decreased when used in combination with Diphenhydramine.
Naratriptan Naratriptan The risk or severity of adverse effects can be increased when Naratriptan is combined with Diphenhydramine.
Paregoric Paregoric The risk or severity of adverse effects can be increased when Morphine is combined with Diphenhydramine.
Penbutolol Penbutolol The metabolism of Acebutolol can be decreased when combined with Diphenhydramine.
Pentazocine Pentazocine The risk or severity of adverse effects can be increased when Pentazocine is combined with Diphenhydramine.
Polyethylene glycol-electrolyte solution (PEG-ES) Polyethylene glycol-electrolyte solution (PEG-ES) The therapeutic efficacy of Polyethylene glycol can be decreased when used in combination with Diphenhydramine.
Psyllium Psyllium The therapeutic efficacy of Plantago seed can be decreased when used in combination with Diphenhydramine.
Ranitidine Ranitidine The metabolism of Ranitidine can be decreased when combined with Diphenhydramine.
Reserpine Reserpine Reserpine may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Rizatriptan Rizatriptan The risk or severity of adverse effects can be increased when Rizatriptan is combined with Diphenhydramine.
Sumatriptan Sumatriptan The risk or severity of adverse effects can be increased when Sumatriptan is combined with Diphenhydramine.
Tacrolimus Tacrolimus The risk or severity of QTc prolongation can be increased when Tacrolimus is combined with Diphenhydramine.
Tizanidine Tizanidine The risk or severity of adverse effects can be increased when Tizanidine is combined with Diphenhydramine.
Zolmitriptan Zolmitriptan The risk or severity of adverse effects can be increased when Zolmitriptan is combined with Diphenhydramine.
Famotidine Injection Famotidine Injection The risk or severity of QTc prolongation can be increased when Famotidine is combined with Diphenhydramine.
Fluconazole Injection Fluconazole Injection The metabolism of Diphenhydramine can be decreased when combined with Fluconazole.
Foscarnet Injection Foscarnet Injection The risk or severity of QTc prolongation can be increased when Foscarnet is combined with Diphenhydramine.
Hydromorphone Injection Hydromorphone Injection The risk or severity of adverse effects can be increased when Hydromorphone is combined with Diphenhydramine.
Levofloxacin Injection Levofloxacin Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Levofloxacin.
Meperidine Injection Meperidine Injection The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Meperidine.
Metoclopramide Injection Metoclopramide Injection The risk or severity of sedation can be increased when Metoclopramide is combined with Diphenhydramine.
Metronidazole Injection Metronidazole Injection The metabolism of Diphenhydramine can be decreased when combined with Metronidazole.
Morphine Injection Morphine Injection The risk or severity of adverse effects can be increased when Morphine is combined with Diphenhydramine.
Zidovudine Injection Zidovudine Injection The metabolism of Diphenhydramine can be decreased when combined with Zidovudine.
Altretamine Altretamine The risk or severity of adverse effects can be increased when Amphetamine is combined with Diphenhydramine.
Cyclosporine Cyclosporine The metabolism of Diphenhydramine can be decreased when combined with Cyclosporine.
Ondansetron Ondansetron The risk or severity of adverse effects can be increased when Ondansetron is combined with Diphenhydramine.
Granisetron Granisetron The risk or severity of adverse effects can be increased when Granisetron is combined with Diphenhydramine.
Torsemide Torsemide The metabolism of Diphenhydramine can be decreased when combined with Torasemide.
Olanzapine Olanzapine The risk or severity of adverse effects can be increased when Olanzapine is combined with Diphenhydramine.
Alosetron Alosetron The risk or severity of adverse effects can be increased when Alosetron is combined with Diphenhydramine.
Dofetilide Dofetilide The serum concentration of Dofetilide can be increased when it is combined with Diphenhydramine.
Entacapone Entacapone The risk or severity of adverse effects can be increased when Entacapone is combined with Diphenhydramine.
Hydroxychloroquine Hydroxychloroquine The metabolism of Diphenhydramine can be decreased when combined with Hydroxychloroquine.
Meloxicam Meloxicam The metabolism of Diphenhydramine can be decreased when combined with Meloxicam.
Oxcarbazepine Oxcarbazepine The risk or severity of adverse effects can be increased when Oxcarbazepine is combined with Diphenhydramine.
Zaleplon Zaleplon The risk or severity of adverse effects can be increased when Zaleplon is combined with Diphenhydramine.
Anakinra Anakinra The metabolism of Diphenhydramine can be increased when combined with Anakinra.
Desloratadine Desloratadine Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Desloratadine.
Linezolid Linezolid The risk or severity of serotonin syndrome can be increased when Linezolid is combined with Diphenhydramine.
Rivastigmine Rivastigmine The therapeutic efficacy of Diphenhydramine can be decreased when used in combination with Rivastigmine.
Trimipramine Trimipramine The metabolism of Diphenhydramine can be decreased when combined with Trimipramine.
Etanercept Injection Etanercept Injection The metabolism of Diphenhydramine can be increased when combined with Etanercept.
Glycopyrrolate Glycopyrrolate The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Glycopyrronium.
Modafinil Modafinil The metabolism of Diphenhydramine can be decreased when combined with Modafinil.
Epinephrine Injection Epinephrine Injection The serum concentration of Epinephrine can be increased when it is combined with Diphenhydramine.
Escitalopram Escitalopram The risk or severity of serotonin syndrome can be increased when Diphenhydramine is combined with Escitalopram.
Zonisamide Zonisamide The risk or severity of adverse effects can be increased when Zonisamide is combined with Diphenhydramine.
Adalimumab Injection Adalimumab Injection The metabolism of Diphenhydramine can be increased when combined with Adalimumab.
Aripiprazole Aripiprazole The metabolism of Aripiprazole can be decreased when combined with Diphenhydramine.
Atomoxetine Atomoxetine The metabolism of Atomoxetine can be decreased when combined with Diphenhydramine.
Dexmethylphenidate Dexmethylphenidate The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dexmethylphenidate.
Atazanavir Atazanavir The risk or severity of QTc prolongation can be increased when Atazanavir is combined with Diphenhydramine.
Almotriptan Almotriptan The risk or severity of adverse effects can be increased when Almotriptan is combined with Diphenhydramine.
Eletriptan Eletriptan The risk or severity of adverse effects can be increased when Eletriptan is combined with Diphenhydramine.
Mefloquine Mefloquine The risk or severity of QTc prolongation can be increased when Mefloquine is combined with Diphenhydramine.
Polyethylene Glycol 3350 Polyethylene Glycol 3350 The therapeutic efficacy of Polyethylene glycol can be decreased when used in combination with Diphenhydramine.
Rosuvastatin Rosuvastatin The metabolism of Rosuvastatin can be decreased when combined with Diphenhydramine.
Vardenafil Vardenafil The risk or severity of QTc prolongation can be increased when Vardenafil is combined with Diphenhydramine.
Alfuzosin Alfuzosin The risk or severity of QTc prolongation can be increased when Alfuzosin is combined with Diphenhydramine.
Aprepitant Aprepitant The metabolism of Diphenhydramine can be decreased when combined with Aprepitant.
Memantine Memantine The serum concentration of Diphenhydramine can be increased when it is combined with Memantine.
Tegaserod Tegaserod The metabolism of Tegaserod can be decreased when combined with Diphenhydramine.
Frovatriptan Frovatriptan The risk or severity of adverse effects can be increased when Frovatriptan is combined with Diphenhydramine.
Gemifloxacin Gemifloxacin The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Gemifloxacin.
Progesterone Progesterone The metabolism of Diphenhydramine can be decreased when combined with Progesterone.
Apomorphine Injection Apomorphine Injection The risk or severity of adverse effects can be increased when Apomorphine is combined with Diphenhydramine.
Infliximab Injection Infliximab Injection The metabolism of Diphenhydramine can be increased when combined with Infliximab.
Oxandrolone Oxandrolone The metabolism of Diphenhydramine can be decreased when combined with Oxandrolone.
Protriptyline Protriptyline Protriptyline may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Duloxetine Duloxetine The metabolism of Duloxetine can be decreased when combined with Diphenhydramine.
Trospium Trospium Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Trospium.
Bosentan Bosentan The metabolism of Diphenhydramine can be increased when combined with Bosentan.
Cinacalcet Cinacalcet The metabolism of Diphenhydramine can be decreased when combined with Cinacalcet.
Erlotinib Erlotinib The metabolism of Erlotinib can be decreased when combined with Diphenhydramine.
Eszopiclone Eszopiclone The risk or severity of CNS depression can be increased when Diphenhydramine is combined with Eszopiclone.
Solifenacin Solifenacin Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Solifenacin.
Voriconazole Voriconazole The risk or severity of QTc prolongation can be increased when Voriconazole is combined with Diphenhydramine.
Dextroamphetamine Dextroamphetamine The risk or severity of adverse effects can be increased when Amphetamine is combined with Diphenhydramine.
Peginterferon Alfa-2b (PEG-Intron) Peginterferon Alfa-2b (PEG-Intron) The metabolism of Diphenhydramine can be increased when combined with Peginterferon alfa-2b.
Pramlintide Injection Pramlintide Injection The risk or severity of reduced gastrointestinal motility can be increased when Pramlintide is combined with Diphenhydramine.
Sodium Oxybate Sodium Oxybate Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Sodium oxybate.
Ibandronate Ibandronate The risk or severity of QTc prolongation can be increased when Ibandronate is combined with Diphenhydramine.
Isocarboxazid Isocarboxazid The risk or severity of adverse effects can be increased when Isocarboxazid is combined with Diphenhydramine.
Ramelteon Ramelteon The risk or severity of adverse effects can be increased when Ramelteon is combined with Diphenhydramine.
Darifenacin Darifenacin The metabolism of Diphenhydramine can be decreased when combined with Darifenacin.
Fentanyl Fentanyl The risk or severity of adverse effects can be increased when Fentanyl is combined with Diphenhydramine.
Pregabalin Pregabalin The therapeutic efficacy of Diphenhydramine can be increased when used in combination with Pregabalin.
Tipranavir Tipranavir The metabolism of Diphenhydramine can be decreased when combined with Tipranavir.
Felbamate Felbamate The metabolism of Diphenhydramine can be decreased when combined with Felbamate.
Ranolazine Ranolazine The serum concentration of Diphenhydramine can be increased when it is combined with Ranolazine.
Abatacept Injection Abatacept Injection The metabolism of Diphenhydramine can be increased when combined with Abatacept.
Rasagiline Rasagiline The risk or severity of adverse effects can be increased when Rasagiline is combined with Diphenhydramine.
Imatinib Imatinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Imatinib.
Varenicline Varenicline The excretion of Varenicline can be decreased when combined with Diphenhydramine.
Gefitinib Gefitinib The metabolism of Diphenhydramine can be decreased when combined with Gefitinib.
Albuterol Albuterol The risk or severity of QTc prolongation can be increased when Salbutamol is combined with Diphenhydramine.
Paliperidone Paliperidone The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Paliperidone.
Bortezomib Bortezomib The risk or severity of QTc prolongation can be increased when Bortezomib is combined with Diphenhydramine.
Clofarabine Injection Clofarabine Injection The serum concentration of Clofarabine can be increased when it is combined with Diphenhydramine.
Lubiprostone Lubiprostone The therapeutic efficacy of Lubiprostone can be decreased when used in combination with Diphenhydramine.
Oxaliplatin Injection Oxaliplatin Injection The serum concentration of Oxaliplatin can be increased when it is combined with Diphenhydramine.
Posaconazole Posaconazole The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Posaconazole.
Primaquine Primaquine The metabolism of Primaquine can be decreased when combined with Diphenhydramine.
Dimenhydrinate Dimenhydrinate The risk or severity of adverse effects can be increased when Dimenhydrinate is combined with Diphenhydramine.
Lisdexamfetamine Lisdexamfetamine Lisdexamfetamine may decrease the sedative and stimulatory activities of Diphenhydramine.
Nabilone Nabilone Nabilone may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Vorinostat Vorinostat The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Vorinostat.
Sorafenib Sorafenib The metabolism of Diphenhydramine can be decreased when combined with Sorafenib.
Sunitinib Sunitinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Sunitinib.
Dronabinol Dronabinol Dronabinol may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Lapatinib Lapatinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Lapatinib.
Levocetirizine Levocetirizine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levocetirizine.
Dasatinib Dasatinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Dasatinib.
Mexiletine Mexiletine The metabolism of Mexiletine can be decreased when combined with Diphenhydramine.
Armodafinil Armodafinil The metabolism of Diphenhydramine can be decreased when combined with Armodafinil.
Paclitaxel (with polyoxyethylated castor oil) Injection Paclitaxel (with polyoxyethylated castor oil) Injection The therapeutic efficacy of Castor oil can be decreased when used in combination with Diphenhydramine.
Temsirolimus Temsirolimus The metabolism of Diphenhydramine can be decreased when combined with Temsirolimus.
Nilotinib Nilotinib The metabolism of Nilotinib can be decreased when combined with Diphenhydramine.
Toremifene Toremifene The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Toremifene.
Bexarotene Bexarotene The metabolism of Diphenhydramine can be decreased when combined with Bexarotene.
Betaine Betaine The therapeutic efficacy of Diphenhydramine can be decreased when used in combination with Glycine betaine.
OnabotulinumtoxinA Injection OnabotulinumtoxinA Injection The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Botulinum toxin type A.
RimabotulinumtoxinB Injection RimabotulinumtoxinB Injection The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Botulinum Toxin Type B.
Etravirine Etravirine The metabolism of Diphenhydramine can be decreased when combined with Etravirine.
Arsenic Trioxide Injection Arsenic Trioxide Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Arsenic trioxide.
Desvenlafaxine Desvenlafaxine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Desvenlafaxine.
Cevimeline Cevimeline The metabolism of Cevimeline can be decreased when combined with Diphenhydramine.
Nebivolol Nebivolol The metabolism of Nebivolol can be decreased when combined with Diphenhydramine.
Tretinoin Tretinoin The metabolism of Diphenhydramine can be decreased when combined with Tretinoin.
Flecainide Flecainide The metabolism of Flecainide can be decreased when combined with Diphenhydramine.
Certolizumab Injection Certolizumab Injection The metabolism of Diphenhydramine can be increased when combined with Certolizumab pegol.
Rufinamide Rufinamide The risk or severity of adverse effects can be increased when Rufinamide is combined with Diphenhydramine.
Midazolam Midazolam The risk or severity of adverse effects can be increased when Midazolam is combined with Diphenhydramine.
Naltrexone Injection Naltrexone Injection The risk or severity of adverse effects can be increased when Naltrexone is combined with Diphenhydramine.
Milnacipran Milnacipran The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Milnacipran.
Sodium Phosphate Sodium Phosphate The therapeutic efficacy of Sodium phosphate, monobasic can be decreased when used in combination with Diphenhydramine.
Fesoterodine Fesoterodine The metabolism of Fesoterodine can be decreased when combined with Diphenhydramine.
Degarelix Injection Degarelix Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Degarelix.
Betaxolol Betaxolol The metabolism of Betaxolol can be decreased when combined with Diphenhydramine.
Iloperidone Iloperidone The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Iloperidone.
Prasugrel Prasugrel The metabolism of Prasugrel can be decreased when combined with Diphenhydramine.
Lacosamide Lacosamide The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lacosamide.
Everolimus Everolimus The metabolism of Diphenhydramine can be decreased when combined with Everolimus.
Dronedarone Dronedarone The metabolism of Dronedarone can be decreased when combined with Diphenhydramine.
AbobotulinumtoxinA Injection AbobotulinumtoxinA Injection The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Botulinum toxin type A.
Palonosetron Injection Palonosetron Injection The risk or severity of adverse effects can be increased when Palonosetron is combined with Diphenhydramine.
Telavancin Injection Telavancin Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Telavancin.
Romidepsin Injection Romidepsin Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Romidepsin.
Tapentadol Tapentadol Tapentadol may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Golimumab Injection Golimumab Injection The metabolism of Diphenhydramine can be increased when combined with Golimumab.
Pazopanib Pazopanib The metabolism of Pazopanib can be decreased when combined with Diphenhydramine.
Asenapine Asenapine The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Asenapine.
Vigabatrin Vigabatrin The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Vigabatrin.
Pitavastatin Pitavastatin The metabolism of Pitavastatin can be decreased when combined with Diphenhydramine.
Oxymorphone Oxymorphone The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Oxymorphone.
Tocilizumab Injection Tocilizumab Injection The metabolism of Diphenhydramine can be increased when combined with Tocilizumab.
Dalfampridine Dalfampridine The serum concentration of Dalfampridine can be increased when it is combined with Diphenhydramine.
Eribulin Injection Eribulin Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Eribulin.
IncobotulinumtoxinA Injection IncobotulinumtoxinA Injection The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Botulinum toxin type A.
Lurasidone Lurasidone The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lurasidone.
Vilazodone Vilazodone The metabolism of Vilazodone can be decreased when combined with Diphenhydramine.
Terbutaline Injection Terbutaline Injection The risk or severity of QTc prolongation can be increased when Terbutaline is combined with Diphenhydramine.
Linagliptin Linagliptin The serum concentration of Linagliptin can be increased when it is combined with Diphenhydramine.
Rilpivirine Rilpivirine The metabolism of Diphenhydramine can be decreased when combined with Rilpivirine.
Cyclophosphamide Injection Cyclophosphamide Injection The metabolism of Diphenhydramine can be decreased when combined with Cyclophosphamide.
Abiraterone Abiraterone The metabolism of Diphenhydramine can be decreased when combined with Abiraterone.
Triptorelin Injection Triptorelin Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Triptorelin.
Ticagrelor Ticagrelor The metabolism of Diphenhydramine can be decreased when combined with Ticagrelor.
Vandetanib Vandetanib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Vandetanib.
Clobazam Clobazam The metabolism of Diphenhydramine can be decreased when combined with Clobazam.
Vemurafenib Vemurafenib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Vemurafenib.
Vismodegib Vismodegib The metabolism of Diphenhydramine can be decreased when combined with Vismodegib.
Crizotinib Crizotinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Crizotinib.
Cabergoline Cabergoline The risk or severity of adverse effects can be increased when Cabergoline is combined with Diphenhydramine.
Ezogabine Ezogabine The risk or severity of adverse effects can be increased when Tiagabine is combined with Diphenhydramine.
Enzalutamide Enzalutamide The metabolism of Diphenhydramine can be increased when combined with Enzalutamide.
Mirabegron Mirabegron The risk or severity of urinary retention can be increased when Diphenhydramine is combined with Mirabegron.
Regorafenib Regorafenib The metabolism of Diphenhydramine can be decreased when combined with Regorafenib.
Linaclotide Linaclotide The therapeutic efficacy of Linaclotide can be decreased when used in combination with Diphenhydramine.
Cabozantinib (thyroid cancer) Cabozantinib (thyroid cancer) The metabolism of Cabozantinib can be decreased when combined with Diphenhydramine.
Bedaquiline Bedaquiline The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Bedaquiline.
Alogliptin Alogliptin The metabolism of Alogliptin can be decreased when combined with Diphenhydramine.
Ponatinib Ponatinib The metabolism of Ponatinib can be decreased when combined with Diphenhydramine.
Pomalidomide Pomalidomide The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Pomalidomide.
Apixaban Apixaban The metabolism of Apixaban can be decreased when combined with Diphenhydramine.
Dabrafenib Dabrafenib The metabolism of Diphenhydramine can be increased when combined with Dabrafenib.
Ospemifene Ospemifene The metabolism of Ospemifene can be decreased when combined with Diphenhydramine.
Levomilnacipran Levomilnacipran The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levomilnacipran.
Vortioxetine Vortioxetine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Vortioxetine.
Perampanel Perampanel Perampanel may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Ibrutinib Ibrutinib The metabolism of Ibrutinib can be decreased when combined with Diphenhydramine.
Ketorolac Injection Ketorolac Injection The metabolism of Diphenhydramine can be decreased when combined with Ketorolac.
Dapagliflozin Dapagliflozin The metabolism of Dapagliflozin can be decreased when combined with Diphenhydramine.
Apremilast Apremilast The metabolism of Diphenhydramine can be increased when combined with Apremilast.
Droxidopa Droxidopa The therapeutic efficacy of Droxidopa can be increased when used in combination with Diphenhydramine.
Ceritinib Ceritinib The metabolism of Diphenhydramine can be decreased when combined with Ceritinib.
Siltuximab Injection Siltuximab Injection The metabolism of Diphenhydramine can be increased when combined with Siltuximab.
Eslicarbazepine Eslicarbazepine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Eslicarbazepine.
Testosterone Injection Testosterone Injection The metabolism of Diphenhydramine can be decreased when combined with Testosterone.
Oritavancin Injection Oritavancin Injection The metabolism of Diphenhydramine can be decreased when combined with Oritavancin.
Hydrocodone Hydrocodone Hydrocodone may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Suvorexant Suvorexant Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Suvorexant.
Methamphetamine Methamphetamine Metamfetamine may decrease the sedative and stimulatory activities of Diphenhydramine.
Tasimelteon Tasimelteon The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Tasimelteon.
Secukinumab Injection Secukinumab Injection The metabolism of Diphenhydramine can be increased when combined with Secukinumab.
Risperidone Injection Risperidone Injection The risk or severity of adverse effects can be increased when Risperidone is combined with Diphenhydramine.
Lenvatinib Lenvatinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Lenvatinib.
Naloxegol Naloxegol The metabolism of Diphenhydramine can be decreased when combined with Naloxegol.
Panobinostat Panobinostat The metabolism of Diphenhydramine can be decreased when combined with Panobinostat.
Haloperidol Injection Haloperidol Injection The risk or severity of QTc prolongation can be increased when Haloperidol is combined with Diphenhydramine.
Ivabradine Ivabradine The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Ivabradine.
Flibanserin Flibanserin The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Flibanserin.
Rolapitant Rolapitant The metabolism of Diphenhydramine can be decreased when combined with Rolapitant.
Brexpiprazole Brexpiprazole The metabolism of Brexpiprazole can be decreased when combined with Diphenhydramine.
Ziprasidone Injection Ziprasidone Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Ziprasidone.
Cariprazine Cariprazine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Cariprazine.
Eluxadoline Eluxadoline The risk or severity of constipation can be increased when Diphenhydramine is combined with Eluxadoline.
Trabectedin Injection Trabectedin Injection The metabolism of Trabectedin can be decreased when combined with Diphenhydramine.
Lesinurad Lesinurad The metabolism of Lesinurad can be decreased when combined with Diphenhydramine.
Brivaracetam Injection Brivaracetam Injection The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Brivaracetam.
Cobicistat Cobicistat The metabolism of Diphenhydramine can be decreased when combined with Cobicistat.
Midodrine Midodrine The risk or severity of Tachycardia can be increased when Midodrine is combined with Diphenhydramine.
Pimavanserin Pimavanserin The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Pimavanserin.
Rucaparib Rucaparib The metabolism of Diphenhydramine can be decreased when combined with Rucaparib.
Ribociclib Ribociclib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Ribociclib.
Doxepin (Insomnia) Doxepin (Insomnia) Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Doxepin.
Plecanatide Plecanatide The therapeutic efficacy of Plecanatide can be decreased when used in combination with Diphenhydramine.
Deutetrabenazine Deutetrabenazine The risk or severity of sedation and somnolence can be increased when Diphenhydramine is combined with Deutetrabenazine.
Valbenazine Valbenazine The metabolism of Valbenazine can be decreased when combined with Diphenhydramine.
Safinamide Safinamide The risk or severity of adverse effects can be increased when Safinamide is combined with Diphenhydramine.
Midostaurin Midostaurin The metabolism of Diphenhydramine can be decreased when combined with Midostaurin.
Enasidenib Enasidenib The metabolism of Diphenhydramine can be decreased when combined with Enasidenib.
Delafloxacin Delafloxacin The risk or severity of QTc prolongation can be increased when Delafloxacin is combined with Diphenhydramine.
Letermovir Letermovir The metabolism of Letermovir can be decreased when combined with Diphenhydramine.
Tetrabenazine Tetrabenazine The risk or severity of sedation and somnolence can be increased when Diphenhydramine is combined with Tetrabenazine.
Buprenorphine Injection Buprenorphine Injection Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Buprenorphine.
Apalutamide Apalutamide The metabolism of Diphenhydramine can be increased when combined with Apalutamide.
Avatrombopag Avatrombopag The metabolism of Diphenhydramine can be increased when combined with Avatrombopag.
Lofexidine Lofexidine The therapeutic efficacy of Diphenhydramine can be increased when used in combination with Lofexidine.
Eliglustat Eliglustat The risk or severity of QTc prolongation can be increased when Eliglustat is combined with Diphenhydramine.
Encorafenib Encorafenib The metabolism of Encorafenib can be decreased when combined with Diphenhydramine.
Ivosidenib Ivosidenib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Ivosidenib.
Elagolix Elagolix The metabolism of Elagolix can be decreased when combined with Diphenhydramine.
Tafenoquine Tafenoquine The metabolism of Tafenoquine can be decreased when combined with Diphenhydramine.
Cannabidiol Cannabidiol The risk or severity of adverse effects can be increased when Cannabidiol is combined with Diphenhydramine.
Dacomitinib Dacomitinib The metabolism of Diphenhydramine can be decreased when combined with Dacomitinib.
Stiripentol Stiripentol The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Stiripentol.
Gilteritinib Gilteritinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Gilteritinib.
Glasdegib Glasdegib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Glasdegib.
Rifamycin Rifamycin The metabolism of Diphenhydramine can be decreased when combined with Rifamycin.
Prucalopride Prucalopride The therapeutic efficacy of Prucalopride can be decreased when used in combination with Diphenhydramine.
Magnesium Citrate Magnesium Citrate The therapeutic efficacy of Magnesium citrate can be decreased when used in combination with Diphenhydramine.
Emapalumab-lzsg Injection Emapalumab-lzsg Injection The metabolism of Diphenhydramine can be increased when combined with Emapalumab.
Siponimod Siponimod The metabolism of Siponimod can be decreased when combined with Diphenhydramine.
Erdafitinib Erdafitinib The metabolism of Erdafitinib can be decreased when combined with Diphenhydramine.
Alpelisib Alpelisib The serum concentration of Diphenhydramine can be decreased when it is combined with Alpelisib.
Brexanolone Injection Brexanolone Injection The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Brexanolone.
Solriamfetol Solriamfetol The risk or severity of Tachycardia can be increased when Solriamfetol is combined with Diphenhydramine.
Triclabendazole Triclabendazole The metabolism of Diphenhydramine can be decreased when combined with Triclabendazole.
Entrectinib Entrectinib The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Entrectinib.
Istradefylline Istradefylline The metabolism of Istradefylline can be decreased when combined with Diphenhydramine.
Pitolisant Pitolisant The therapeutic efficacy of Pitolisant can be decreased when used in combination with Diphenhydramine.
Fedratinib Fedratinib The metabolism of Diphenhydramine can be decreased when combined with Fedratinib.
Lefamulin Lefamulin Lefamulin may increase the QTc-prolonging activities of Diphenhydramine.
Phenytoin Injection Phenytoin Injection The metabolism of Phenytoin can be decreased when combined with Diphenhydramine.
Fosphenytoin Injection Fosphenytoin Injection The metabolism of Fosphenytoin can be decreased when combined with Diphenhydramine.
Voxelotor Voxelotor The metabolism of Voxelotor can be decreased when combined with Diphenhydramine.
Avapritinib Avapritinib The metabolism of Avapritinib can be decreased when combined with Diphenhydramine.
Lumateperone Lumateperone The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Lumateperone.
Lasmiditan Lasmiditan The risk or severity of serotonin syndrome can be increased when Diphenhydramine is combined with Lasmiditan.
Selumetinib Selumetinib The metabolism of Selumetinib can be decreased when combined with Diphenhydramine.
Lemborexant Lemborexant Lemborexant may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Daratumumab and Hyaluronidase-fihj Injection Daratumumab and Hyaluronidase-fihj Injection The therapeutic efficacy of Hyaluronidase can be decreased when used in combination with Diphenhydramine.
Fenfluramine Fenfluramine The risk or severity of serotonin syndrome can be increased when Fenfluramine is combined with Diphenhydramine.
Fostemsavir Fostemsavir The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Fostemsavir.
Pertuzumab, Trastuzumab, and Hyaluronidase-zzxf Injection Pertuzumab, Trastuzumab, and Hyaluronidase-zzxf Injection The therapeutic efficacy of Hyaluronidase can be decreased when used in combination with Diphenhydramine.
Octreotide Octreotide The risk or severity of QTc prolongation can be increased when Octreotide is combined with Diphenhydramine.
Pralsetinib Pralsetinib The metabolism of Diphenhydramine can be decreased when combined with Pralsetinib.
Satralizumab-mwge Injection Satralizumab-mwge Injection The serum concentration of Diphenhydramine can be decreased when it is combined with Satralizumab.
Relugolix Relugolix The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Relugolix.
Viloxazine Viloxazine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Viloxazine.
Theophylline Theophylline The metabolism of Theophylline can be decreased when combined with Diphenhydramine.
Indomethacin Indomethacin The metabolism of Diphenhydramine can be decreased when combined with Indomethacin.
Mefenamic Acid Mefenamic Acid The metabolism of Diphenhydramine can be decreased when combined with Mefenamic acid.
Trazodone Trazodone The risk or severity of QTc prolongation can be increased when Trazodone is combined with Diphenhydramine.
Hydroxyurea Hydroxyurea The metabolism of Diphenhydramine can be decreased when combined with Hydroxyurea.
Floxuridine Floxuridine The metabolism of Diphenhydramine can be decreased when combined with Floxuridine.
Phenobarbital Phenobarbital The metabolism of Phenobarbital can be decreased when combined with Diphenhydramine.
Metaxalone Metaxalone The risk or severity of adverse effects can be increased when Metaxalone is combined with Diphenhydramine.
Levorphanol Levorphanol The risk or severity of adverse effects can be increased when Levorphanol is combined with Diphenhydramine.
Primidone Primidone The risk or severity of adverse effects can be increased when Primidone is combined with Diphenhydramine.
Methsuximide Methsuximide The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Methsuximide.
Diethylpropion Diethylpropion Diethylpropion may decrease the sedative and stimulatory activities of Diphenhydramine.
Chlorpromazine Chlorpromazine The metabolism of Diphenhydramine can be decreased when combined with Chlorpromazine.
Diazepam Diazepam The risk or severity of adverse effects can be increased when Diazepam is combined with Diphenhydramine.
Oxazepam Oxazepam The risk or severity of adverse effects can be increased when Oxazepam is combined with Diphenhydramine.
Flurazepam Flurazepam The risk or severity of adverse effects can be increased when Flurazepam is combined with Diphenhydramine.
Clorazepate Clorazepate The risk or severity of adverse effects can be increased when Clorazepic acid is combined with Diphenhydramine.
Lorazepam Lorazepam The risk or severity of adverse effects can be increased when Lorazepam is combined with Diphenhydramine.
Amantadine Amantadine The serum concentration of Diphenhydramine can be increased when it is combined with Amantadine.
Meprobamate Meprobamate The risk or severity of adverse effects can be increased when Meprobamate is combined with Diphenhydramine.
Chlordiazepoxide Chlordiazepoxide The risk or severity of adverse effects can be increased when Chlordiazepoxide is combined with Diphenhydramine.
Bromocriptine Bromocriptine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Bromocriptine.
Metaproterenol Metaproterenol The risk or severity of Tachycardia can be increased when Orciprenaline is combined with Diphenhydramine.
Tranylcypromine Tranylcypromine The risk or severity of adverse effects can be increased when Tranylcypromine is combined with Diphenhydramine.
Phenelzine Phenelzine The risk or severity of adverse effects can be increased when Phenelzine is combined with Diphenhydramine.
Procarbazine Procarbazine The risk or severity of adverse effects can be increased when Procarbazine is combined with Diphenhydramine.
Ergoloid Mesylates Ergoloid Mesylates The risk or severity of adverse effects can be increased when Ergoloid mesylate is combined with Diphenhydramine.
Minocycline Minocycline Minocycline may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Prochlorperazine Prochlorperazine The risk or severity of adverse effects can be increased when Prochlorperazine is combined with Diphenhydramine.
Thioridazine Thioridazine The metabolism of Diphenhydramine can be decreased when combined with Thioridazine.
Trifluoperazine Trifluoperazine The risk or severity of adverse effects can be increased when Trifluoperazine is combined with Diphenhydramine.
Dapsone Dapsone The metabolism of Diphenhydramine can be decreased when combined with Dapsone.
Sulfadiazine Sulfadiazine The metabolism of Diphenhydramine can be decreased when combined with Sulfadiazine.
Oxycodone Oxycodone The risk or severity of adverse effects can be increased when Oxycodone is combined with Diphenhydramine.
Methadone Methadone The risk or severity of adverse effects can be increased when Methadone is combined with Diphenhydramine.
Oxybutynin Oxybutynin Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Oxybutynin.
Benztropine Benztropine The metabolism of Benzatropine can be decreased when combined with Diphenhydramine.
Maprotiline Maprotiline The risk or severity of adverse effects can be increased when Maprotiline is combined with Diphenhydramine.
Trihexyphenidyl Trihexyphenidyl Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Trihexyphenidyl.
Orphenadrine Orphenadrine Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Orphenadrine.
Perphenazine Perphenazine The risk or severity of adverse effects can be increased when Perphenazine is combined with Diphenhydramine.
Fluphenazine Fluphenazine The risk or severity of adverse effects can be increased when Fluphenazine is combined with Diphenhydramine.
Phentermine Phentermine Phentermine may decrease the sedative and stimulatory activities of Diphenhydramine.
Amoxapine Amoxapine The metabolism of Diphenhydramine can be decreased when combined with Amoxapine.
Doxorubicin Doxorubicin The metabolism of Diphenhydramine can be decreased when combined with Doxorubicin.
Mechlorethamine Mechlorethamine The therapeutic efficacy of Diphenhydramine can be decreased when used in combination with Mechlorethamine.
Pyridostigmine Pyridostigmine The therapeutic efficacy of Diphenhydramine can be decreased when used in combination with Pyridostigmine.
Carbamazepine Carbamazepine Carbamazepine may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Molindone Molindone The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Molindone.
Clonidine Clonidine The risk or severity of sedation can be increased when Clonidine is combined with Diphenhydramine.
Prazosin Prazosin The serum concentration of Prazosin can be increased when it is combined with Diphenhydramine.
Cimetidine Cimetidine The metabolism of Cimetidine can be decreased when combined with Diphenhydramine.
Warfarin Warfarin The metabolism of Diphenhydramine can be decreased when combined with Warfarin.
Clonazepam Clonazepam The risk or severity of adverse effects can be increased when Clonazepam is combined with Diphenhydramine.
Loperamide Loperamide The metabolism of Loperamide can be decreased when combined with Diphenhydramine.
Promethazine Promethazine The metabolism of Diphenhydramine can be decreased when combined with Promethazine.
Digoxin Digoxin The risk or severity of QTc prolongation can be increased when Digoxin is combined with Diphenhydramine.
Loxapine Loxapine The risk or severity of adverse effects can be increased when Loxapine is combined with Diphenhydramine.
Chloroquine Chloroquine The metabolism of Diphenhydramine can be decreased when combined with Chloroquine.
Quinine Quinine The metabolism of Quinine can be decreased when combined with Diphenhydramine.
Ethosuximide Ethosuximide The risk or severity of adverse effects can be increased when Ethosuximide is combined with Diphenhydramine.
Lactulose Lactulose The therapeutic efficacy of Lactulose can be decreased when used in combination with Diphenhydramine.
Sulfinpyrazone Sulfinpyrazone The metabolism of Diphenhydramine can be decreased when combined with Sulfinpyrazone.
Chlorothiazide Chlorothiazide The serum concentration of Chlorothiazide can be increased when it is combined with Diphenhydramine.
Chlorthalidone Chlorthalidone The serum concentration of Chlorthalidone can be increased when it is combined with Diphenhydramine.
Metolazone Metolazone The serum concentration of Metolazone can be increased when it is combined with Diphenhydramine.
Secobarbital Secobarbital The risk or severity of adverse effects can be increased when Secobarbital is combined with Diphenhydramine.
Desipramine Desipramine The metabolism of Desipramine can be decreased when combined with Diphenhydramine.
Amitriptyline Amitriptyline The metabolism of Amitriptyline can be decreased when combined with Diphenhydramine.
Imipramine Imipramine The metabolism of Imipramine can be decreased when combined with Diphenhydramine.
Probenecid Probenecid The metabolism of Diphenhydramine can be decreased when combined with Probenecid.
Quinidine Quinidine The metabolism of Diphenhydramine can be decreased when combined with Quinidine.
Procainamide Procainamide The metabolism of Procainamide can be decreased when combined with Diphenhydramine.
Isoniazid Isoniazid The metabolism of Diphenhydramine can be decreased when combined with Isoniazid.
Disopyramide Disopyramide The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Disopyramide.
Valproic Acid Valproic Acid Valproic acid may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Tamoxifen Tamoxifen The metabolism of Diphenhydramine can be decreased when combined with Tamoxifen.
Butabarbital Butabarbital The risk or severity of adverse effects can be increased when Butabarbital is combined with Diphenhydramine.
Methimazole Methimazole The metabolism of Diphenhydramine can be decreased when combined with Methimazole.
Chlorpropamide Chlorpropamide The metabolism of Diphenhydramine can be decreased when combined with Chlorpropamide.
Glucagon Injection Glucagon Injection Diphenhydramine may increase the gastrointestinal motility reducing activities of Glucagon.
Tolbutamide Tolbutamide The metabolism of Tolbutamide can be decreased when combined with Diphenhydramine.
Tolazamide Tolazamide The metabolism of Diphenhydramine can be decreased when combined with Tolazamide.
Cyclobenzaprine Cyclobenzaprine The risk or severity of CNS depression can be increased when Cyclobenzaprine is combined with Diphenhydramine.
Niacin Niacin The metabolism of Diphenhydramine can be decreased when combined with Niacin.
Baclofen Baclofen The risk or severity of adverse effects can be increased when Baclofen is combined with Diphenhydramine.
Doxylamine Doxylamine Doxylamine may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Cyproheptadine Cyproheptadine Cyproheptadine may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Clemastine Clemastine The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Clemastine.
Chlorpheniramine Chlorpheniramine The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Chlorpheniramine.
Brompheniramine Brompheniramine The risk or severity of adverse effects can be increased when Dexbrompheniramine is combined with Diphenhydramine.
Meclizine Meclizine The risk or severity of adverse effects can be increased when Meclizine is combined with Diphenhydramine.
Methyclothiazide Methyclothiazide The serum concentration of Methyclothiazide can be increased when it is combined with Diphenhydramine.
Hydrochlorothiazide Hydrochlorothiazide The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Hydrochlorothiazide.
Dantrolene Dantrolene The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Dantrolene.
Chlorzoxazone Chlorzoxazone The risk or severity of adverse effects can be increased when Chlorzoxazone is combined with Diphenhydramine.
Carisoprodol Carisoprodol The risk or severity of adverse effects can be increased when Carisoprodol is combined with Diphenhydramine.
Methocarbamol Methocarbamol The risk or severity of adverse effects can be increased when Methocarbamol is combined with Diphenhydramine.
Disulfiram Disulfiram The risk or severity of QTc prolongation can be increased when Disulfiram is combined with Diphenhydramine.
Propranolol (Cardiovascular) Propranolol (Cardiovascular) The metabolism of Propranolol can be decreased when combined with Diphenhydramine.
Nortriptyline Nortriptyline The metabolism of Diphenhydramine can be decreased when combined with Nortriptyline.
Nadolol Nadolol The metabolism of Nadolol can be decreased when combined with Diphenhydramine.
Butorphanol Injection Butorphanol Injection The risk or severity of adverse effects can be increased when Butorphanol is combined with Diphenhydramine.
Nalbuphine Injection Nalbuphine Injection The risk or severity of adverse effects can be increased when Nalbuphine is combined with Diphenhydramine.
Oxytocin Injection Oxytocin Injection The risk or severity of QTc prolongation can be increased when Oxytocin is combined with Diphenhydramine.
Trimethobenzamide Trimethobenzamide Trimethobenzamide may increase the central nervous system depressant (CNS depressant) activities of Diphenhydramine.
Flavoxate Flavoxate Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Flavoxate.
Papaverine Papaverine The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Papaverine.
Fluorouracil Injection Fluorouracil Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Fluorouracil.
Acetazolamide Acetazolamide The risk or severity of adverse effects can be increased when Acetazolamide is combined with Diphenhydramine.
Ketoconazole Ketoconazole The metabolism of Diphenhydramine can be decreased when combined with Ketoconazole.
Pyrantel Pyrantel The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Pyrantel.
Thiotepa Injection Thiotepa Injection The therapeutic efficacy of Diphenhydramine can be decreased when used in combination with Thiotepa.
Isoxsuprine Isoxsuprine The risk or severity of Tachycardia can be increased when Diphenhydramine is combined with Isoxsuprine.
Vinblastine Vinblastine The metabolism of Diphenhydramine can be decreased when combined with Vinblastine.
Metoprolol Metoprolol The metabolism of Diphenhydramine can be decreased when combined with Metoprolol.
Hydroxyzine Hydroxyzine The risk or severity of QTc prolongation can be increased when Hydroxyzine is combined with Diphenhydramine.
Thiothixene Thiothixene The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Thiothixene.
Alprazolam Alprazolam The risk or severity of adverse effects can be increased when Alprazolam is combined with Diphenhydramine.
Temazepam Temazepam The risk or severity of adverse effects can be increased when Temazepam is combined with Diphenhydramine.
Triazolam Triazolam The risk or severity of adverse effects can be increased when Triazolam is combined with Diphenhydramine.
Dicyclomine Dicyclomine Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Dicyclomine.
Hyoscyamine Hyoscyamine Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Hyoscyamine.
Propantheline Propantheline Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Propantheline.
Trimethoprim Trimethoprim The metabolism of Diphenhydramine can be decreased when combined with Trimethoprim.
Diltiazem Diltiazem The metabolism of Diltiazem can be decreased when combined with Diphenhydramine.
Nifedipine Nifedipine The metabolism of Nifedipine can be decreased when combined with Diphenhydramine.
Timolol Timolol The metabolism of Timolol can be decreased when combined with Diphenhydramine.
Verapamil Verapamil The metabolism of Diphenhydramine can be decreased when combined with Verapamil.
Atenolol Atenolol The metabolism of Atenolol can be decreased when combined with Diphenhydramine.
Pindolol Pindolol The risk or severity of adverse effects can be increased when Pindolol is combined with Diphenhydramine.
Cisplatin Injection Cisplatin Injection The serum concentration of Diphenhydramine can be increased when it is combined with Cisplatin.
Piroxicam Piroxicam The metabolism of Diphenhydramine can be decreased when combined with Piroxicam.
Glyburide Glyburide The metabolism of Diphenhydramine can be decreased when combined with Glyburide.
Glipizide Glipizide The metabolism of Diphenhydramine can be decreased when combined with Glipizide.
Indapamide Indapamide The risk or severity of QTc prolongation can be increased when Indapamide is combined with Diphenhydramine.
Pentamidine Injection Pentamidine Injection The metabolism of Pentamidine can be decreased when combined with Diphenhydramine.
Labetalol Labetalol The metabolism of Diphenhydramine can be decreased when combined with Labetalol.
Leuprolide Injection Leuprolide Injection The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Leuprolide.
Gemfibrozil Gemfibrozil The metabolism of Diphenhydramine can be decreased when combined with Gemfibrozil.
Guanabenz Guanabenz The risk or severity of Tachycardia can be increased when Guanabenz is combined with Diphenhydramine.
Pimozide Pimozide The metabolism of Pimozide can be decreased when combined with Diphenhydramine.
Flurbiprofen Flurbiprofen The metabolism of Diphenhydramine can be decreased when combined with Flurbiprofen.
Amiodarone Amiodarone The metabolism of Diphenhydramine can be decreased when combined with Amiodarone.
Buspirone Buspirone The metabolism of Buspirone can be decreased when combined with Diphenhydramine.
Lovastatin Lovastatin The metabolism of Diphenhydramine can be decreased when combined with Lovastatin.
Ciprofloxacin Ciprofloxacin The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Ciprofloxacin.
Diclofenac Diclofenac The metabolism of Diphenhydramine can be decreased when combined with Diclofenac.
Fluoxetine Fluoxetine The serum concentration of Diphenhydramine can be increased when it is combined with Fluoxetine.
Nimodipine Nimodipine The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Nimodipine.
Clozapine Clozapine The metabolism of Diphenhydramine can be decreased when combined with Clozapine.
Estazolam Estazolam The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Estazolam.
Idarubicin Idarubicin The metabolism of Idarubicin can be decreased when combined with Diphenhydramine.
Ofloxacin Ofloxacin The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Ofloxacin.
Clarithromycin Clarithromycin The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Clarithromycin.
Etodolac Etodolac The metabolism of Diphenhydramine can be decreased when combined with Etodolac.
Felodipine Felodipine The metabolism of Diphenhydramine can be decreased when combined with Felodipine.
Nabumetone Nabumetone The metabolism of Diphenhydramine can be decreased when combined with Nabumetone.
Simvastatin Simvastatin The metabolism of Diphenhydramine can be decreased when combined with Simvastatin.
Teniposide Injection Teniposide Injection The metabolism of Diphenhydramine can be decreased when combined with Teniposide.
Itraconazole Itraconazole The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Itraconazole.
Atovaquone Atovaquone The metabolism of Diphenhydramine can be decreased when combined with Atovaquone.
Sotalol Sotalol The metabolism of Sotalol can be decreased when combined with Diphenhydramine.
Zolpidem Zolpidem Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Zolpidem.
Doxazosin Doxazosin The metabolism of Doxazosin can be decreased when combined with Diphenhydramine.
Isradipine Isradipine The risk or severity of QTc prolongation can be increased when Isradipine is combined with Diphenhydramine.
Omeprazole Omeprazole The metabolism of Diphenhydramine can be decreased when combined with Omeprazole.
Cisapride Cisapride The metabolism of Diphenhydramine can be decreased when combined with Cisapride.
Gabapentin Gabapentin The risk or severity of adverse effects can be increased when Gabapentin is combined with Diphenhydramine.
Fluvastatin Fluvastatin The metabolism of Diphenhydramine can be decreased when combined with Fluvastatin.
Venlafaxine Venlafaxine The metabolism of Diphenhydramine can be decreased when combined with Venlafaxine.
Nizatidine Nizatidine The therapeutic efficacy of Diphenhydramine can be decreased when used in combination with Nizatidine.
Fluvoxamine Fluvoxamine The metabolism of Fluvoxamine can be decreased when combined with Diphenhydramine.
Nefazodone Nefazodone The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Nefazodone.
Lamotrigine Lamotrigine The risk or severity of adverse effects can be increased when Lamotrigine is combined with Diphenhydramine.
Losartan Losartan The risk or severity of QTc prolongation can be increased when Losartan is combined with Diphenhydramine.
Tramadol Tramadol The risk or severity of serotonin syndrome can be increased when Tramadol is combined with Diphenhydramine.
Vinorelbine Injection Vinorelbine Injection The metabolism of Diphenhydramine can be decreased when combined with Vinorelbine.
Moexipril Moexipril The risk or severity of QTc prolongation can be increased when Moexipril is combined with Diphenhydramine.
Lansoprazole Lansoprazole The metabolism of Diphenhydramine can be decreased when combined with Lansoprazole.
Ifosfamide Injection Ifosfamide Injection The metabolism of Ifosfamide can be decreased when combined with Diphenhydramine.
Nicardipine Nicardipine The metabolism of Diphenhydramine can be decreased when combined with Nicardipine.
Bupropion Bupropion The metabolism of Diphenhydramine can be decreased when combined with Bupropion.
Ticlopidine Ticlopidine The metabolism of Diphenhydramine can be decreased when combined with Ticlopidine.
Saquinavir Saquinavir The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Saquinavir.
Metformin Metformin The serum concentration of Metformin can be increased when it is combined with Diphenhydramine.
Lamivudine Lamivudine The serum concentration of Lamivudine can be increased when it is combined with Diphenhydramine.
Riluzole Riluzole The risk or severity of adverse effects can be increased when Riluzole is combined with Diphenhydramine.
Glimepiride Glimepiride The metabolism of Diphenhydramine can be decreased when combined with Glimepiride.
Ritonavir Ritonavir The metabolism of Diphenhydramine can be decreased when combined with Ritonavir.
Clomipramine Clomipramine The metabolism of Diphenhydramine can be decreased when combined with Clomipramine.
Zafirlukast Zafirlukast The metabolism of Diphenhydramine can be decreased when combined with Zafirlukast.
Mirtazapine Mirtazapine Diphenhydramine may increase the serotonergic activities of Mirtazapine.
Topiramate Topiramate The risk or severity of hyperthermia and oligohydrosis can be increased when Diphenhydramine is combined with Topiramate.
Zileuton Zileuton The metabolism of Diphenhydramine can be decreased when combined with Zileuton.
Valsartan Valsartan The metabolism of Diphenhydramine can be decreased when combined with Valsartan.
Pramipexole Pramipexole Diphenhydramine may increase the sedative activities of Pramipexole.
Donepezil Donepezil The therapeutic efficacy of Diphenhydramine can be decreased when used in combination with Donepezil.
Nelfinavir Nelfinavir The metabolism of Diphenhydramine can be decreased when combined with Nelfinavir.
Azithromycin Azithromycin The risk or severity of QTc prolongation can be increased when Diphenhydramine is combined with Azithromycin.
Loratadine Loratadine Diphenhydramine may increase the anticholinergic activities of Loratadine.
Carvedilol Carvedilol The metabolism of Carvedilol can be decreased when combined with Diphenhydramine.
Nilutamide Nilutamide The metabolism of Diphenhydramine can be decreased when combined with Nilutamide.
Selegiline Selegiline The risk or severity of adverse effects can be increased when Selegiline is combined with Diphenhydramine.
Bicalutamide Bicalutamide The metabolism of Diphenhydramine can be decreased when combined with Bicalutamide.
Sertraline Sertraline The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Sertraline.
Propafenone Propafenone The metabolism of Diphenhydramine can be decreased when combined with Propafenone.
Irbesartan Irbesartan The metabolism of Diphenhydramine can be decreased when combined with Irbesartan.
Tamsulosin Tamsulosin The metabolism of Tamsulosin can be decreased when combined with Diphenhydramine.
Ropinirole Ropinirole Diphenhydramine may increase the sedative activities of Ropinirole.
Quetiapine Quetiapine The metabolism of Quetiapine can be decreased when combined with Diphenhydramine.
Cetirizine Cetirizine The risk or severity of adverse effects can be increased when Cetirizine is combined with Diphenhydramine.
Paroxetine Paroxetine The metabolism of Diphenhydramine can be decreased when combined with Paroxetine.
Tolcapone Tolcapone The risk or severity of adverse effects can be increased when Tolcapone is combined with Diphenhydramine.
Citalopram Citalopram The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Citalopram.
Capecitabine Capecitabine The metabolism of Diphenhydramine can be decreased when combined with Capecitabine.
Efavirenz Efavirenz The risk or severity of adverse effects can be increased when Efavirenz is combined with Diphenhydramine.
Sildenafil Sildenafil The metabolism of Sildenafil can be decreased when combined with Diphenhydramine.
Celecoxib Celecoxib The metabolism of Diphenhydramine can be decreased when combined with Celecoxib.
Rosiglitazone Rosiglitazone The metabolism of Diphenhydramine can be decreased when combined with Rosiglitazone.
Tolterodine Tolterodine The metabolism of Tolterodine can be decreased when combined with Diphenhydramine.
Thalidomide Thalidomide Diphenhydramine may increase the central nervous system depressant (CNS depressant) activities of Thalidomide.
Nateglinide Nateglinide The metabolism of Nateglinide can be decreased when combined with Diphenhydramine.
Galantamine Galantamine The risk or severity of QTc prolongation can be increased when Galantamine is combined with Diphenhydramine.
Levetiracetam Levetiracetam The risk or severity of adverse effects can be increased when Diphenhydramine is combined with Levetiracetam.
Rabeprazole Rabeprazole The metabolism of Diphenhydramine can be decreased when combined with Rabeprazole.
Terbinafine Terbinafine The metabolism of Diphenhydramine can be decreased when combined with Terbinafine.

* This branded product is no longer on the market. Generic alternatives may be available.

** These products are not currently approved by the FDA for safety, effectiveness, and quality. Federal law generally requires that prescription drugs in the U.S. be shown to be both safe and effective prior to marketing. Please see the FDA website for more information on unapproved drugs (http://www.fda.gov/AboutFDA/Transparency/Basics/ucm213030.htm ) and the approval process (http://www.fda.gov/Drugs/ResourcesForYou/Consumers/ucm054420.htm ).

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