Diphenhydramine 2D skeletal.svg

Diphenhydramine is an antihistamine mainly used to treat allergies. It is also used for insomnia, symptoms of the common cold, tremor in parkinsonism, and nausea. It is used by mouth, injection into a vein, and injection into a muscle. Maximal effect is typically around two hours after a dose and effects can last for up to seven hours.

Synonyms
Benadryl