Benadryl (Diphenhydramine) Vs. Dramamine (Dimenhydrinate): What Is The Difference?
In our latest question and answer, the pharmacist discusses the difference between diphenhydramine and dimenhydrinate.
What is the difference between Benadryl (diphenhydramine) and Dramamine (dimenhydrinate)?
Sep 23, 2022- Benadryl and Dramamine are closely related medications, but Benadryl is more potent and more sedating because Dramamine contains diphenhydramine combined with a stimulant compound that reduces drowsiness.
- Both medications work against motion sickness through their antihistamine effects, but you might prefer Dramamine if Benadryl's sedation is too strong for you.
Answer
Hello and thanks for reaching out!
Diphenhydramine, available as the brand name Benadryl and dimenhydrinate, available as Dramamine, are very closely related medications.
Both are considered first-generation antihistamines and therefore, have very similar effects. However, Benadryl is generally more potent and has stronger effects on a milligram to milligram dose basis.
Interestingly enough, dimenhydrinate, as a drug compound, actually contains diphenhydramine (about 55% of the compound weight comes from diphenhydramine). I discuss this more in the next sections.
Dramamine (Dimenhydrinate)
As mentioned, the drug dimenhydrinate consists of two chemical compounds, bound together. These compounds are:
- Diphenhydramine
- 8-chlorotheophylline
Dimenhydrinate contains nearly 55% diphenhydramine by weight. You can see in the molecular structure below what dimenhydrinate is composed of (the left structure being diphenhydramine and the right being 8-chlorotheophylline, which is combined in a salt form to form 'dimenhydrinate').
Specifically, dimenhydrinate is classified as the " chlorotheophylline salt of diphenhydramine"
8-Chlorotheophylline, on its own, is considered a stimulant and is actually in the same drug class as caffeine (xanthine chemical class). 8-Chlorotheophylline, when combined in a salt form with diphenhydramine, reduces the sedative effects of diphenhydramine, which is why it tends to be a little less sedating than Benadryl.
So, overall, you could say that Dramamine is a less sedating form of Benadryl.
You could certainly take Benadryl to treat/prevent motion sickness, and it is effective for that. It is the antihistamine/anticholinergic effects of the drug that reduce nausea. However, sometimes Benadryl is too sedating, and that's where Dramamine may have some value to you.
Benadryl (Diphenhydramine)
Benadryl contains diphenhydramine, a sedating first generation antihistamine. In addition to its use for allergies, it is beneficial in the treatment of vertigo related to motion sickness and insomnia, due to its sedating properties. In fact, it is a common ingredient in over-the-counter sleep products, such as ZzzQuil.
Benadryl contains diphenhydramine, a sedating first generation antihistamine.
In addition to its use for allergies, it is beneficial in the treatment of vertigo related to motion sickness and insomnia, due to its sedating properties.
Due to the sedating properties of diphenhydramine, it is a common ingredient in over-the-counter sleep products, such as ZzzQuil.
Benadryl (diphenhydramine) is given in doses of 25-50mg every four to six hours.
Summary Of Differences
- Diphenhydramine (Benadryl) is a first-generation antihistamine used for the treatment of allergies and insomnia, due to its sedative effect.
- Dimenhydrinate (Dramamine) is a drug compound that contains around 55% diphenhydramine and 45% 8-chlorotheophylline.
- Dimenhydrinate may cause slightly less sedation than diphenhydramine and is still effective for treating motion sickness.
Final Words
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References & sources
Glossary — Terms in This Answer
- Antihistamines
- Medications that block the effects of histamine, a chemical in the body that causes allergy symptoms like itching and swelling.
- First-generation antihistamines
- Older antihistamines that easily cross into the brain and typically cause drowsiness as a side effect.
- Diphenhydramine
- The active ingredient in Benadryl that reduces allergy symptoms and can cause sedation.
- Dimenhydrinate
- The active ingredient in Dramamine, made by combining diphenhydramine with another compound to reduce drowsiness.
- 8-Chlorotheophylline
- A stimulant compound combined with diphenhydramine in Dramamine to counteract some of its sedating effects.
- Anticholinergic effects
- A type of drug action that reduces nausea and other symptoms by blocking certain nerve signals in the body.
- Vertigo
- A dizzying sensation where the room appears to spin, often caused by motion sickness.
- Xanthine
- A chemical class of stimulant drugs that includes caffeine and similar compounds.
Dr. Brian Staiger, PharmD
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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