Experimental assessment of selected antimotion drugs.

Space motion sickness (SMS) has been a perplexing problem in both the Soviet and U.S. manned space programs. Both the sensory conflict theory (neuronal signal mismatch) and the cephalad fluid shift concept explain the mechanism. This paper reviews the mechanism of action of various drugs that primarily affect brain blood flow or brain metabolism. In particular, Cavinton (apovincamic acid ethyl ester) has been used successfully in offsetting SMS in experimental test subjects.