Dose-dependent inhibition of experimental arterial thrombosis by carbenicillin and ticarcillin

An experimental model of canine arterial thrombosis was used to study the prophylactic antithrombotic effectiveness of carbenicillin and ticarcillin, two semisynthetic penicillins which have been shown to inhibit platelet function in vivo. Isolated peripheral arterial segments were injected with pronase and biopsied at 24 hours. In untreated dogs, 89% of injected segments totally occluded with thrombus. Prophylactic treatment for 3 to 7 days with carbenicillin or ticarcillin in low doses (250 mg/kg/day) or high doses (750 mg/kg/ day) significantly decreased the incidence of total occlusion to 53% and 6%, respectively. The dose-dependent inhibition of arterial thrombosis correlated with dose-dependent inhibition of platelet function. Prophylactic treatment with aspirin in low doses (650 mg/day) or high doses (2600 mg/day) did not significantly decrease the incidence of total occlusion in this model. Carbenicillin and ticarcillin are effective experimental antithrombotic agents.