Diphenhydramine

Diphenhydramine hydrochloride (trade name Benadryl, as produced by J&J, or Dimedrol outside the U.S. & Canada. Nytol as a sleeping pill.) is an over-the-counter (OTC) antihistamine, sedative and hypnotic. It may also be used for the treatment of extrapyramidal side effects of typical antipsychotics. It is a member of the ethanolamine class of antihistaminergic agents.

The brand Benadryl is currently trademarked in the United States by Pfizer, however many drug store chains and retail outlets manufacture less-costly generic versions under their own store brands, often sold in boxes that share similarities in packaging size, colors, and appearance of the Pfizer pill.