Reversible Acute Renal Insufficiency with Combination of Enalapril and Diuretics in a Patient with a Single Renal-Artery Stenosis

Acute renal insufficiency induced by angiotensin converting enzyme inhibitors has been previously re ported in patients with bilateral renal-artery stenosis or renal-artery stenosis in a solitary kidney [1,2], Recently, reversible acute renal failure has been described with combination of enalapril and diuretics in patients with out renal-artery stenosis [3].Renal impairment with such a combination in patients with single renal-artery steno sis has not been reported.A 68-year-old hypertensive patient was admitted for dyspnea on exertion.He had been previously treated by nifedipine (30 mg daily).His blood pressure was 260/130 mm Hg: plasma creatinine concentration was 110 umol/1 and examination showed a grade 11 hypertensive retino pathy.Nifedipine was withdrawn and clonidine (0.150 mg daily) was started in addition to altizide (15 mg daily) and spironolactone (25 mg daily).As his blood pressure was not under control after 6 days, enalapril (10 mg daily) was introduced.24 h later the 24-hour urinary output decreased from 1,400 ml to 300 ml while blood pressure gradually decreased from 200/120 to 120/80 mm Hg; serum creatinine level rose to 397 pmol/1.Spironolac tone, altizide and enalapril were discontinued; within 48 h urinary output increased to 1,700 ml and serum creati nine level fell over 4 days to 109 umol/l.An intravenous pyelogram showed a 9 cm right kidney and a 12.5 cm left