Potential adverse interaction between aspirin and lisinopril in hypertensive rats

The potential clinical effect of aspirin (ASA) in patients treated with angiotensin converting enzyme (ACE) inhibitors is debatable. Several studies have suggested that ASA attenuates the beneficial effects of ACE inhibitors in hypertension, congestive heart failure (CHF) or coronary artery disease (CAD) and have questioned the safety of using ASA concomitantly with these agents. The present study aims to investigate the possible interaction between ASA and ACE inhibitor in hypertensive rats. Hypertension was induced in adult male Wistar rats using Methylprednisolone (MP) 20 mg/kg per week s.c. for 2 weeks. The systolic blood pressure (SBP) was measured by noninvasive BP technique. The effect of Lisinopril (LS) 15 mg/kg per day and that of combination of LS and ASA; 100 and 25 mg/kg per day p.o. was studied on hypertension induced by glucocorticoid. Concurrent ASA treatment with LS did not hinder the hypotensive effect of LS at either dose. However ASA 100 mg/kg per day caused mortality in animals and produced massive cardiac necrosis and renal damage as evident from histopathology. Treatment with ASA 25 mg/kg per day caused lower mortality with variable effects on cardiac and renal tissues. These results indicate that ASA attenuates the beneficial effects of ACE inhibitor on survival in hypertensive rats and this effect was more pronounced at higher dose of ASA.