dimenhydrinate

Dimenhydrinate is a first-generation antihistamine and anticholinergic agent primarily used for the prevention and treatment of motion sickness, nausea, and vertigo. Chemically, it is a salt consisting of two active components: diphenhydramine (an H1 receptor antagonist) and 8-chlorotheophylline (a chlorinated derivative of theophylline). The drug exerts its therapeutic effects primarily through the diphenhydramine moiety, which competitively inhibits H1 receptors in the vestibular system and the chemoreceptor trigger zone (CTZ) of the brain, thereby reducing vestibular stimulation and nausea. It also possesses significant antimuscarinic properties that contribute to its anti-emetic and sedative effects. The 8-chlorotheophylline component was originally included to mitigate the drowsiness associated with diphenhydramine, although its stimulant effect is relatively weak. Dimenhydrinate is widely available as an over-the-counter medication and is also used in clinical settings for symptomatic relief of peripheral vertigo.

Brand names

DramamineGravolDriminateVertirosanVomex ATravel-GumCalm-XDinateHydrate

Other names

diphenhydramine teoclatediphenhydramine chlorotheophyllinate