Taking NyQuil With Azithromycin (Z-Pak)

In our latest question and answer, the pharmacist discusses whether or not it is safe to take NyQuil and azithromycin (Z-Pak) together.

3 min read Updated Jun 2026 Read by 21,637 people
Taking NyQuil With Azithromycin (Z-Pak)
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TJS asked

I started with my first dose of Azithromycin today, two 250mg around 6 hours ago. Can I take Nyquil tonight before bed?

Nov 23, 2022
The quick answer
  • NyQuil and NyQuil Severe are safe to take together with azithromycin without any known drug interactions.
  • Azithromycin is an antibiotic that treats bacterial infections but does not work against viral infections like the flu or common cold.
  • NyQuil can help manage symptoms like fever, body aches, congestion, and cough that may occur with infections.
A quick summary of Dr. Brian Staiger, PharmD's full answer below, condensed by AI from that answer only (not from any outside source). The pharmacist's answer is the source of record.

Answer

There is no known drug interaction between azithromycin (Z-Pak) and Nyquil (acetaminophen, dextromethorphan, and doxylamine). They can be safely taken together.

'NyQuil Severe', which contains one additional ingredient when compared to the 'original' NyQuil, is also safe to take with a Z-Pak.

Below, I discuss each medication in more detail

Information About The Z-Pak

A Z-pak consists of six tablets of azithromycin 250 mg. Most commonly, it is prescribed to be taken as follows:

  • Take two tablets (500mg) by mouth on the first day of therapy
  • Take one tablet (250mg) by mouth for the following four days

Azithromycin, the antibiotic in the Z-Pak, is a macrolide antibiotic that can treat a variety of infections including bronchitis, sinus infections, ear infections, skin infections, sexually transmitted infections, and more.

Azithromycin can cover several types of bacteria but is not effective in treating the flu, the common cold, or other viral infections.

Like most antibiotics, azithromycin may cause diarrhea, nausea, vomiting, and abdominal pain. Macrolides are more likely to cause these types of side effects, but azithromycin is one of the more tolerable drugs in the class.

Another concern with azithromycin is that it can cause QT prolongation (a type of arrhythmia) in patients with a past medical history related to the heart. Drug interactions can also be a concern so always check each new medication prior to starting a new therapy. 

Information About Nyquil

Nyquil comes in a variety of formulations and contains several different ingredients. Nyquil Cold & Flu contains the following:

  • Acetaminophen (pain relief, fever reducer)
  • Dextromethorphan (cough suppressant)
  • Doxylamine (antihistamine)

 'NyQuil Severe' adds on a nasal decongestant, phenylephrine.

Acetaminophen is an analgesic that can be taken for a wide variety of acute and chronic pain ailments. Acetaminophen has a half-life of 2-3 hours. About 85-98% of the drug gets absorbed and it reaches peak concentrations within 30-60 minutes.

Typically, acetaminophen can start working within 15 minutes. Acetaminophen can have negative impacts on the liver, especially at higher doses for an extended period of time.

Dextromethorphan (commonly referred to as DM on many over-the-counter products) is a cough suppressant that reduces the urge to cough. It is best to prevent a bothersome dry cough or a cough that doesn’t involve mucus from the lower respiratory system.

Doxylamine is a first-generation antihistamine that is more likely to cause sedation and drowsiness as compared to second-generation antihistamines (i.e., loratadine, cetirizine).

Other first-generation antihistamines include Benadryl (diphenhydramine), Dramamine (dimenhydrinate), Chlor-Trimeton (chlorpheniramine), Tavist (clemastine), and Phenergan (promethazine), among others. 

Final Words

NyQuil often represents a good medication choice for those suffering from a variety of symptoms that may come about from an infection, such as a fever, body aches, congestion, and a cough.

As mentioned, NyQuil (and NyQuil Severe) are safe to take with azithromycin.

Thanks for your question!

References & sources
  1. Azithromycin Monograph — PubChem
  2. Dextromethorphan Monograph — PubChem
  3. Guaifenesin Monograph — PubChem
  4. Acetaminophen Monograph — PubChem
  5. Doxylamine Monograph — PubChem
Glossary — Terms in This Answer
Macrolide antibiotic
A class of antibiotics that work by stopping bacterial growth and can treat various infections.
QT prolongation
A type of irregular heartbeat rhythm that can be caused by certain medications, especially in people with heart problems.
Analgesic
A medication that relieves pain.
Half-life
The time it takes for the body to break down and eliminate half of a drug dose.
Peak concentrations
The highest level of a drug present in the bloodstream after taking a dose.
Cough suppressant
A medication that reduces the urge to cough.
Antihistamine
A medication that blocks histamine, a chemical released during allergic reactions, to reduce symptoms like itching and sneezing.
First-generation antihistamine
An older type of antihistamine that is more likely to cause drowsiness compared to newer versions.
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Dr. Brian Staiger, PharmD
About the pharmacist

Dr. Brian Staiger, PharmD

Clinical Pharmacy

Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified

Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...

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