Increased risk of bleeding. Reports of hypersensitivity including rash, angioedema or hematologic reaction; cross-reactivity among thienopyridines; TTP. Discontinue treatment 5 days prior to surgery if antiplatelet effect is not desired. Premature discontinuation may increase risk of CV events. Metabolism to active metabolite can be impaired by generic variations in CYP2C19 & by concomitant medications that interfere w/ CYP2C19. Avoid concomitant use w/ omeprazole or esomeprazole. Increased major bleeding in patients w/ recent transient ischemic attack/stroke using combination of aspirin & clopidogrel bisulfate. Should be used during pregnancy only if clearly needed. Discontinue nursing or discontinue the drug, taking into account the importance of therapy to the mother.