Scopolamine alone or combined with ephedrine in seasickness: a double-blind, placebo-controlled study.

In seasickness, the central cholinergic-noradrenergic balance is disturbed. Capsules of identical appearance--containing scopolamine hydrobromide 0.3 mg, scopolamine hydrobromide 0.3 mg + ephedrine hydrochloride 25 mg, or placebo--were given prophylactically three times daily to 30 naval cadets during a crossing. In this randomized, double-blind trial the superiority of scopolamine and scopolamine + ephedrine over placebo was confirmed. Ephedrine did not clearly increase the effectiveness of scopolamine. One subject in the scopolamine group and one in the placebo group interrupted the treatment. The symptoms of seasickness as well as the number of side-effects of the drugs decreased on the third day of the study. Scopolamine alone or in combination with ephedrine proved useful in the prevention of seasickness in young healthy male volunteers.