Motion sickness: comparison of metoclopramide and diphenhydramine to placebo.

Objectives: This is an evaluation of the efficacy of metoclopramide (MTCP) or diphenhydramine (DPH) to relieve symptoms of motion sickness in patients being transported via ambulance in a mountainous setting.

Methods: This is a prospective, randomized, double-blinded, placebo-controlled study of patients transported by ambulance in the Sierra Nevada mountains of Fresno County. Consenting patients who met the inclusion criteria were asked to rate their motion sickness every five minutes using a visual analog scale (VAS) during transport.