Abstract
Objective: To study the effects of loading dose of 300mg versus 600mg of clopidogrel on platelet aggregation in patients with coronary artery disease ( CAD).
Material and Methods: This study was conducted on patients with CAD, not already taking any anti-platelet drugs, admitted in cardiology department Lady Reading Hospital from 1st June to 15th July 2005. Patients were randomized into two groups. Baseline platelet aggregation was measured followed by oral clopidogrel 300mg (group A) or 600mg (group B). Platelet aggregation was measured serially at 2, 4 and 6 hours.
Results: Total number of patients was 52 (16 males & 36 females). In group A, the baseline mean platelet aggregation was 2.36 +/- 1.5 ohms, there was significant difference at 2 hours i.e. 1.24 +/- 1.2 ohms (P<0.001), 4 hours i.e. 1.05 +/- 1.05 ohms (P<0.001) and at 6 hours i.e. 0.71 +/- 0.72 ohms (P<0.001) as compared to baseline. In group B, the baseline mean platelet aggregation was 2.32 +/- 1.98 ohms. There was significant difference in platelet aggregation time at 2 hours i.e. 1.37 +/- 1.39 ohms (P<0.001) 4 hours i.e. 0.92 +/- 0.97 ohms (P<0.001) and at 6 hours i.e. 0.35 +/- 0.61 ohms (P<0.001) as compared to baseline. No significant difference was observed on platelet aggregation in-group "A" and group "B" at 2 hours (P=0.479), 4 hours (P=0.858) and 6 hours (P=0.756).
Conclusion: Clopidogrel 300mg as a loading dose is as effective as clopidogrel 600 mg in inhibiting platelet aggregation in patients with coronary artery disease.