What is "etanautine"

Etanautine, also known as diphenhydramine monoacefyllinate, is an anticholinergic used as an antiparkinsonian agent. It is a 1:1 salt of diphenhydramine with acefylline, similar to the diphenhydramine/8-chlorotheophylline combination product dimenhydrinate.

As with dimenhydrinate, the stimulant effect of the acefylline counteracts the sedative effect from the diphenhydramine, resulting in an improved therapeutic profile.

The 1:2 salt diphenhydramine diacefylline (with two molecules of acefylline to each molecule of diphenhydramine) is also used in medicine, under the brand name Nautamine.