What Is Benadryl?
Benadryl® (diphenhydramine hydrochloride) is an antihistamine medication available both over the counter and with a prescription. Many people may wonder, "What is Benadryl used for?"
The active ingredient of Benadryl is diphenhydramine hydrochloride. Diphenhydramine is part of a class of drugs called antihistamines. Specifically, it is an H1 receptor antagonist. This means that it blocks a specific type of histamine receptor in the body (known as H1 receptors). Since allergic reactions are partly caused by the release of histamine from certain cells in the body, diphenhydramine can help relieve or prevent allergy symptoms.
Diphenhydramine also blocks acetylcholine receptors, an action which produces some of the bothersome side effects of the medication (such as dry mouth or difficulty urinating) but also makes the drug useful for some uses (such as for Parkinson's disease or for relieving a runny nose due to the common cold).
Like many antihistamines, diphenhydramine also works as a sedative. This action has made the medication useful as a sleep aid but also limits the usefulness of the medication for other uses (since drowsiness can be a bothersome side effect).
(Click Benadryl Ingredients for more information on what Benadryl is made up of and what ingredients are in the generic versions of this medication.)