Anti-emetic drug effects on pilot performance: Granisetron vs. ondansetron

Background: The objectives of this study were to evaluate the effects of two anti-emetic drugs, granisetron (1 mg tablets/2 mg oral dose) and ondansetron (8 mg tablets/8 mg oral dose) on flying and mission performance in an F-16 research simulator. Methods: The experimental approach, involving 9 pilots, was a placebo controlled, double blind, crossover design. Each pilot flew three defensive counter air missions. Data on nine measures of flying performance were collected via the simulator data recorder. In addition, ratings on mission and flying performance were recorded by simulator instructor pilots. Data were also collected on symptoms and side effects, mood, and vigilance. Results: This study, carried out in the context of a simulated tactical air-to-air combat mission, produced no significant differences between the effects of the target drugs and placebo on any of the nine objective flying performance measures, including a composite measure of landing performance. There were no differences in evaluator ratings of routine mission flying or air combat performance. Pilots could not distinguish active drug from placebo and there were no differences on any of the mood scales. Conclusions: These results confirm our earlier findings that the drugs of interest are well tolerated and produce no cognitive, psychomotor or subjective state changes. In this study, there was no evidence of performance degradation caused by either granisetron or ondansetron when tested in a complex, military task environment.