Angiotensin converting enzyme (ACE) inhibitors and renal function. A review of the current status.

Angiotensin converting enzyme (ACE) inhibitors are well established in the treatment of hypertension and cardiac failure. Experimental studies in rats have suggested that these agents may protect renal function in chronic nephropathy by a mechanism other than simply lowering the systemic blood pressure. In human studies of incipient diabetic nephropathy, worsening of microalbuminuria was prevented during 3 years of ACE inhibition. ACE inhibitors reduce arterial blood pressure in chronic nephropathy, and may cause a fall in glomerular filtration rate. In diabetic nephropathy, proteinuria was reduced by 2 months' treatment with enalapril to less than half of the values obtained in a control group treated with metoprolol. Nonrandomised trials have suggested that ACE inhibitors may slow the deterioration of renal function, but no comparisons with other antihypertensive agents in prospective studies have been published to date. In chronic renal failure, ACE inhibitors may worsen anaemia and hyperkalaemia. Renovascular hypertension can be treated with ACE inhibitors, but the treatment may lead to a compromised renal function. The dosage of these drugs should be reduced in renal failure and therapy should be started cautiously in this setting, with close monitoring of blood pressure, renal function and plasma potassium.