USE OF PROMETHAZINE TO HASTEN ADAPTATION TO PROVOCATIVE MOTION

In an earlier study, the authors found that severely motion sick indiv iduals could be greatly relieved of their symptoms by intramuscular in jections of promethazine (50 mg) or scopolamine (.5 mg).(1) Comparable 50-mg injections of promethazine also have been found effective in al leviating symptoms of space motion sickness.(2) The concern has risen, however, that such drugs may delay or retard the acquisition of adapt ation to stressful environments. In the current study, we controlled a rousal using a mental arithmetic task and precisely equated the exposu re history (number of head movements during rotation) of a placebo, co ntrol group and an experimental group who had received promethazine. N o differences in total adaptation or in rates of adaptation were prese nt between the two groups. Another experimental group also received pr omethazine and was allowed to make as many head movements as they coul d, before reaching nausea, up to 800. This group showed a greater leve l of adaptation than the placebo group. These results suggest a strate gy for dealing with space motion sickness that is described.