Benadryl (Diphenhydramine) Vs. Dramamine (Dimenhydrinate): What Is The Difference?

In our latest question and answer, the pharmacist discusses the difference between diphenhydramine and dimenhydrinate.

Question

What is the difference between Benadryl (diphenhydramine) and Dramamine (dimenhydrinate)?

Asked by Samantha On Sep 23, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Sep 23, 2022
Last updated Sep 23, 2022

Key points

  • Benadryl (diphenhydramine) and Dramamine (dimenhydrinate) are very similar drugs, with similar effects.
  • Dramamine (dimenhydrinate), as a drug compound, consists of 55% diphenhydramine (the rest is 8-chlorotheophylline).
  • Both Benadryl and Dramamine are effective in treating motion sickness, but Dramamine is generally less sedating.

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').

Dimenhydrinate Compound Structure

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 Diphenhydramine Structure

Benadryl contains diphenhydramine, a sedating first generation antihistamine. In addition to its use for allergies, it is beneficial in the treatment with 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

  • Diphenhydramine Monograph, PubChem
  • Dimenhydrinate Monograph, PubChem
  • Efficacy and Pharmacological Appropriateness of Cinnarizine and Dimenhydrinate in the Treatment of Vertigo and Related Symptoms, PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 11 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Feel free to send him an email at Hello@HelloPharmacist.com! You can also connect with Dr. Brian Staiger on LinkedIn.

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