Diphenhydramine Vs. Dimenhydrinate: What Is The Difference?

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

Diphenhydramine Vs. Dimenhydrinate: What Is The Difference?
Mar 31, 2018

Samantha asked

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

At a glance

  • Dramamine consists of diphenhydramine bound to 8-chlorotheophylline. 8-chlorotheophylline has mild stimulant effects and can slightly off-set the sedation of diphenhydramine.


Diphenhydramine, available as the brand name Benadryl and dimenhydrinate, available as Dramamine, are very closely related medications. Interestingly enough, dimenhydrinate actually contains diphenhydramine, which is discuss below.

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.

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.


  • 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 commonly used off-label for Meniere's syndrome and hyperemesis gravidarum.

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