American journal of clinical pathology
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Am. J. Clin. Pathol. · Sep 1977
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of "anti-platelet" drugs on bleeding time and platelet aggregation in normal human subjects.
The effects on hemostasis of several commonly used drugs previously described as inhibiting platelet function were evaluated in a randomized, double-blind study of 54 normal volunteers. The subjects were each given a single dose of aspirin, chlorpromazine, glyceryl guaiacolate, diphenhydramine, indomethacin or lactose placebo. A single dose of aspirin significantly prolonged the template bleeding time and inhibited secondary platelet aggregation two and 24 hours after ingestion. ⋯ Diphenhydramine did not affect either. These findings suggest that standard doses of many commonly used "anti-platelet" drugs may have little clinical effect on the hemostatic mechanism in normal man. Results of in-vitro platelet-drug incubations may not be directly applicable to in-vivo hemostasis.