In vivo antiplatelet effect of intravenous alum in rabbits

Traditionally known as a haemostatic agent, alum shows a paradoxical effect of increased prothrombin and partial thromboplastin times. This study investigated the in vivo effect of alum on platelet aggregation and bleeding time in rabbits. The collagen-induced platelet aggregation of platelet-rich plasma samples from 14 healthy rabbits was measured turbidometrically using a platelet aggregometer, before and 1 hour after intravenous injection of alum. Collagen-induced platelet aggregation was significantly reduced after alum injection. Bleeding time from an ear puncture in 8 rabbits was also significantly prolonged after intravenous alum injection. These results suggest that the use of alum as an oral antiplatelet drug could be explored further, taking into account possible side-effects especially in renal compromised patients.