title: Effectiveness and duration of intramuscular antimotion sickness medications.
abstract: Motion sickness inhibits gastric motility, making the oral route ineffective for medications. The intramuscular route is an effective alternative. The rotating chair was used to produce the M 111 level of motion sickness on the Graybiel Symptom Scale. The intramuscular medications given 30 minutes before rotation were compared with placebo (saline, 1 mL) for effectiveness and duration in increasing the number of tolerated head movements. Average placebo number of head movements was 294. Promethazine 25 mg increased head movements by 78% (P < .05), with a duration of 12 hours. Scopolamine 0.2 mg increased head movements by 91% (P < .05), with a duration of 4 hours. The effect of caffeine 250 mg and ephedrine 25 mg was not significant. When combined with scopolamine, ephedrine produced an 32% additive effect. Scopolamine 0.08 mg, 0.1 mg, and 0.2 mg and also promethazine 12.5 mg and 25 mg were significant (P < .05). Promethazine appears to be the drug of choice for intramuscular use because of a longer duration and a high level of effectiveness. Scopolamine was of high effectiveness, but had a duration of 4 hours. It was eight times as potent by the intramuscular as by the oral route.
authors: Department of Pharmacology, Louisiana State University Medical Center, Shreveport 71130.
authors: C D
authors: CD
authors: Wood
authors: J J
authors: JJ
authors: Stewart
authors: M J
authors: MJ
authors: Wood
authors: M
authors: M
authors: Mims
mesh_terms: D002110:Caffeine / Q000494:pharmacology*; D004809:Ephedrine / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D009041:Motion Sickness / Q000209:etiology / Q000517:prevention & control*; D011398:Promethazine / Q000494:pharmacology* / Q000627:therapeutic use; D012601:Scopolamine / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D002110:Caffeine; D012601:Scopolamine; D011398:Promethazine; D004809:Ephedrine