Drug interactions between Aspirin Low Strength and hydrochlorothiazide/moexipril

aspirin ↔ moexipril

Applies to:Aspirin Low Strength (aspirin) and hydrochlorothiazide/moexipril

MONITOR: Some investigators suggest that coadministration with aspirin may attenuate the vasodilator and hypotensive effects of ACE inhibitors. In addition, some have found that the benefits of ACE inhibitors on morbidity and mortality in post-acute myocardial infarction, coronary heart disease, and particularly congestive heart failure may be compromised or even nullified by aspirin. The proposed mechanism is aspirin inhibition of cyclooxygenase, resulting in suppression of prostaglandin synthesis and prostaglandin-mediated hemodynamic effects of ACE inhibitors. However, evidence of a negative interaction is largely contradictory, and interpretation of relevant data has often been complicated by multiple confounding elements as well as the retrospective or post hoc nature of most studies. Available data seem to indicate that low-dose aspirin (less than 236 mg/day, and especially less than 100 mg/day) is unlikely, or at least significantly less likely, to interfere with ACE inhibitor effects, although susceptibility to the interaction may be subject to some degree of interpatient variability.

MANAGEMENT: Based on current data, it is difficult to determine the likelihood of a negative interaction between aspirin and ACE inhibitors and its clinical relevance during long-term therapy, particularly in congestive heart failure. Current recommendations generally do not preclude combination use in patients with cardiovascular diseases or risk factors that might otherwise benefit from the drugs independently. However, patients receiving long-term therapy with the combination should undergo regular blood pressure and other appropriate clinical monitoring such as renal function assessments. The lowest therapeutic dosage of aspirin should be used.