Drug Interactions between bismuth subsalicylate and clopidogrel

MONITOR: Clopidogrel has been shown to potentiate the inhibition of platelet aggregation due to aspirin. Single-dose studies have not shown a prolongation of bleeding time when aspirin was added to clopidogrel; however, the risk of gastrointestinal (GI) bleeding may be increased. A large clinical trial reported that clopidogrel 75 mg/day plus aspirin 75 to 325 mg/day for up to 1 year was associated with a higher incidence of major GI bleeding (1.3% vs 0.7% with aspirin alone). These two medications are routinely used together for their additive antiplatelet, antistroke effect. The safety of chronic administration of aspirin or other salicylates with clopidogrel has not been established.

MANAGEMENT: Until further data are available, caution is recommended, especially in patients at risk of bleeding (i.e., GI ulceration), if clopidogrel is coadministered on a long-term basis with drugs that may cause GI lesions. Patients should be advised to promptly report any signs of bleeding to their physician, including pain, red or black stools, or bloody or coffee-ground emesis. Patients should also be counseled to avoid any other over-the-counter salicylate products.