PHENYTOIN AS A COUNTERMEASURE FOR MOTION SICKNESS IN NASA MARITIME OPERATIONS

Seasickness is the most prevalent form of motion sickness and is an op erational problem during Space Shuttle Solid-fueled Rocket Booster (SR B) retrieval. Phenytoin has been shown to protect against motion sickn ess induced by Coriolis stress. We exposed SRB recovery personnel to o ff-vertical rotation and sea motion after phenytoin or placebo. Phenyt oin blood levels of at least 9 mug/ml were protective against motion s ickness at sea. No change in susceptibility to nitrogen narcosis was s een in divers in chamber tests at 460 KPa. Phenytoin was used during p erformance of critical and hazardous tasks during training and actual SRB recovery operations. Phenytoin is an effective operational counter measure for motion sickness for selected SRB crewmembers.