clopidogrel + rifampicin

The combination of clopidogrel and rifampicin represents an important drug interaction rather than a fixed-dose combination product. Rifampicin (also called rifampin) significantly affects the metabolism of clopidogrel, enhancing its conversion to the active metabolite. ## Mechanism of Interaction Rifampicin is a potent inducer of CYP450 enzymes, particularly CYP2C19, which is responsible for converting clopidogrel to its active metabolite[3]. When administered together, rifampicin substantially increases the formation of clopidogrel's active metabolite, leading to: 1. Enhanced antiplatelet effects of clopidogrel[1][2] 2. Greater P2Y12 receptor blockade[2][4] 3. Increased inhibition of platelet aggregation[2][4] In a study with healthy volunteers, rifampicin significantly enhanced clopidogrel active metabolite production, with the area-under-the-curve increasing from 89±22 ng h mL⁻¹ with clopidogrel alone to 335±86 ng h mL⁻¹ with the combination[2]. This led to substantially greater P2Y12 receptor blockade and reduced platelet aggregation. ## Clinical Significance This interaction is clinically significant as it may increase the risk of bleeding complications during treatment with both medications[1]. The interaction is classified as "minimally clinically significant" according to drug interaction databases, suggesting that while the risk exists, it can be managed with appropriate monitoring and precautions[3]. ## Considerations for Use When using this combination: - Patients may be at increased risk for bleeding complications[1] - Platelet aggregation responses to low concentrations of ADP are particularly sensitive to the enhanced P2Y12 blockade caused by this interaction[2] - Healthcare providers should assess the risk-benefit ratio and consider alternative medications or monitoring plans when these drugs must be used together[3] This interaction demonstrates how drug metabolism inducers can significantly alter the pharmacokinetics and pharmacodynamics of medications that require metabolic activation, such as clopidogrel.

Other names

clopidogrel + rifampinrifampin + clopidogrel