Summary
Recent studies suggest that cytochrome P450 (CYP) 3A4 metabolized statins attenuate
the antiaggregatory effect of clopidogrel. We evaluated how CYP3A4 metabolized statins
and non- CYP3A4 metabolized statins influence platelet aggregation when given concomitantly
with clopidogrel. Sixty-six stable patients with ischemic heart disease were included
in this parallel group study. All patients were on clopidogrel and aspirin. Thirty-three
patients received a CYP3A4 metabolized statin (simvastatin or atorvastatin), and 33
were treated with a non- CYP3A4 metabolized statin (pravastatin). The antiplatelet
effect of clopidogrel was assessed at inclusion and 21 days after statin discontinuation.
Platelet function was evaluated by two methods 1) optical platelet aggregometry after
stimulation with 20 and 30 μM ADP, and 2 and 4 mg/l collagen, respectively, 2) a Platelet
FunctionAnalyzer-100. The primary effect measure was final platelet aggregation after
stimulation with 20 μM ADP. No difference was observed between patients treated with
a CYP3A4 metabolized statin and patients receiving a non-CYP3A4 metabolized statin
(30% point (7–42) versus 20% point (9–32), p=0.83). Platelet aggregation was not improved
by discontinuation of statins for 21 days. Indeed, we found that statin treatment
given concomitantly with clopidogrel resulted in an improved platelet inhibition when
compared to clopidogrel given alone. The antiplatelet effect of clopidogrel is not
attenuated by concomitant treatment with a CYP3A4 metabolized statin in patients with
clinical stable ischemic heart disease.
Keywords
Ischemic heart disease - lipid mediators - platelet pharmacology