Discordant effects of enalapril and lisinopril on systemic and renal hemodynamics

To investigate whether there are quantitative differences between the angiotensin converting enzyme (ACE) inhibitors enalapril and lisinopril with respect to their influence on renal versus systemic hemodynamics in humans.

This was a 12-month, single-blind crossover study in which eight patients with essential hypertension were examined. The main outcome measures were blood pressure and renal hemodynamics during ACE inhibition and/or angiotensin II infusion.

The decrease in blood pressure was dose dependent and not significantly different between both drugs. However, with the same blood pressure reduction effective renal plasma flow (ERPF) rose more and filtration fraction (FF) and renovascular resistance (RVR) decreased more after administration of enalapril (20 mg) than after administration of lisinopril (20 mg) (ERPF: 21.9% +/- 2.0% versus 4.4% +/- 2.5%, p = 0.018; FF: -16.7% +/- 2.8% versus -6.6% +/- 2.5%, p = 0.028; RVR: -28.1% +/- 3.1% versus -18.5% +/- 3.7%, p = 0.018). During angiotensin II infusion, with a similar increase in systemic blood pressure, the change in ERPF, FF, and RVR again was more pronounced during enalapril than during lisinopril (ERPF: -14.6% +/- 2.9% versus -7.8% +/- 3.3%, p = 0.018; FF: 18.3% +/- 5.9% versus 12.8% +/- 6.0%, p = 0.028; RVR: 36.7% +/- 8.1% versus 21.9% +/- 4.3%, p = 0.018).

We conclude that in a situation of a comparable systemic blood pressure reduction, enalapril has greater effects on renal hemodynamics than lisinopril. This finding may have implications for the choice of a certain ACE inhibitor in specific disease conditions.