['This study seeks to evaluate the comparative role of alpha-fluoromethylhistidine and diphenhydramine in the prevention of motion sickness.', 'The role of histaminergic mechanisms in motion sickness were evaluated in a feline model. Twenty-six female cats were studied. A variety of doses of fluoromethylhistidine and diphenhydramine were administered before motion testing.', 'Fluoromethylhistidine was effective in preventing motion sickness. The efficacy was dose dependent. In contrast, diphenhydramine failed to prevent motion sickness in any of the tested doses.'] Does alpha-Fluoromethylhistidine but not diphenhydramine prevent motion-induced emesis in the cat?