Piprinhydrinate is compositon of Diphenylpyraline and 8-chloroteophylline. 8-Chlorotheophylline is a stimulant drug of the xanthine chemical class, with physiological effects similar to caffeine. Diphenylpyraline is an antihistamine that prevents, but does not reverse, responses mediated by histamine alone. Diphenylpyraline antagonizes most of the pharmacological effects of histamine, including urticaria and pruritus. Also, diphenylpyraline may exhibit anticholinergic actions (as do most of the antihistamines) and may thus provide a drying effect on the nasal mucosa. 8-Chlorotheophylline main use is in combination with Diphenylpyraline or diphenhydramine in the antiemetic Piprinhydrinate and dimenhydrinate. Diphenylpyraline (or diphenhydramine) reduces nausea but causes drowsiness, and the stimulant properties of 8-Chlorotheophylline help ward off that side-effect.
