Renal toxicity of enalapril in very elderly patients with progressive, severe congestive heart failure.

We evaluated the safety of enalapril administration in 20 very old (76 +/- 7 years) patients with rapidly progressive congestive heart failure (deteriorating from New York Heart Association class 2 to class 4 on admission). They were all given increasing doses of enalapril regardless of concomitant diuretic therapy and state of hydration. Renal function deteriorated in four patients (group A) and remained unchanged in 16 (group B). The mean pretreatment serum creatinine level in group A was significantly higher than that in group B (2.4 vs 1.3 mg/dl, p less than 0.001). No patient with a serum creatinine level less than 1.9 mg/dl on admission had further impairment of renal function. Groups A and B did not differ by age, concomitant diseases (including hypertension and diabetes mellitus), or medications (including diuretics) or by in-hospital serum electrolyte concentrations and blood pressure. Renal damage was noted during the initial four days of the study and was reversible following discontinuation of enalapril. Our data suggest that enalapril can be safely administered to very old patients with rapidly progressive congestive heart failure provided that the initial serum creatinine level is below 1.9 mg/dl. In patients with a higher serum creatinine level, careful monitoring and prompt discontinuation of enalapril administration can prevent irreversible renal damage.