<prompt> The drug of choice for prophylaxis of motion sickness is:-PromethazineOndansetronMetoclopramideDomperidone  <response>: Best DrugDoc for prophylaxis of motion sickness - Hyoscine scopolamine If hyoscine is not given in the option, then the answer would be first generation Antihistaminics. First generation Antihistaminics can cross the blood brain barrier and also have strong Anti-cholinergic propeies. First generation Antihistaminics - Promethazine 