Pharmacology: Pharmacokinetics: Clopidogrel is rapidly but incompletely absorbed following oral administration; absorption appears to be about 50%. It is a prodrug and is extensively metabolized in the liver following absorption, mainly to the inactive carboxylic acid derivative. The active metabolites appears to be a thiol derivative but has not been identified in plasma. Clopidogrel and the carboxylic acid derivatives are highly protein bound. Clopidogrel and its metabolites are excreted about equally in urine and in feces.