Effect of Cardioselective Beta Blocker on Lisinopril Treated Isolated Rabbit’s Heart

Background: Certain drugs produce unpredictable responses when used in emergency conditions. These variable outcomes may be harmful or beneficial for the patient. Objective: This study has been conducted to evaluate the pharmacodynamic interaction between angiotensin converting enzyme inhibitor and metoprolol, a selective blocker of β1 receptors. Cardioselective beta blockers are commonly used to treat hypertension, arrhythmias and ischemic heart disease. Method: In this study, 20 healthy male rabbits were selected and divided into two groups. Effective dose of Lisinopril (10 mg/kg) was administered orally via oral feeding, for 9 days. By using Langendroff’s technique, the effects of metoprolol were observed in isolated hearts. Result: The data showed that the effective dose of Lisinopril (10 mg/kg daily orally) increases the inotropic and chronotropic effects of metoprolol significantly (p<0.05). Conclusion: Therefore, lisinopril, an inhibitor of angiotensin converting enzyme may increase the response of cardioselective beta blocker metoprolol in isolated rabbit’s heart.