DIURETICS POTENTIATE ANGIOTENSIN-CONVERTING ENZYME INHIBITOR-INDUCED ACUTE-RENAL-FAILURE

Previous studies suggest that angiotensin converting enzyme (ACE) inhi bitors cause reversible acute renal failure (ARF) in patients with hyp ertension, congestive heart failure (CHF), and renal disease. These pa tients often receive diuretics concomitantly with ACE inhibitors. The purpose of this study was to examine whether ACE inhibitors alone prod uce ARF or whether they do so when used in combination with diuretics. The medical records of patients taking ACE inhibitors without or with diuretics were reviewed. Complete data from 74 patients were obtained and the data were analyzed. These 74 patients had a diagnosis of hype rtension, CHF or diabetes mellitus. BUN and serum creatinine values be fore, during, and after discontinuation of ACE inhibitor therapy for a mean period of 8.7 months were collected. Seventy-four patients were divided into two groups: Group A (n = 41) patients who received ACE in hibitors alone; Group B (n = 33) patients who received a combination o f an ACE inhibitor and a diuretic. ARF developed in 1 of 41 (2.4%) Gro up A patients compared to 11 of 33 (33%) Group B patients. This group difference was highly significant (P < .001). In Group A, mean serum c reatinine before (1.24 +/- .34 mg/dl) was identical to that 1.23 +/- . 33 mg/dl) after 8.7 months of ACE inhibitor therapy, whereas in Group B, post-mean serum creatinine (3.11 +/- 2.27 mg/dl) was significantly (P < .01) higher than pre-mean serum creatinine (1.65 +/- .85 mg/dl). CHF patients had a higher rate of ARF than patients with other diagnos es. Urinary electrolytes showed that 4 of 6 Group B patients had chlor ide concentration less than 20 mEq/l. Renal function recovered to base line upon discontinuation of combination therapy but saline infusion a ppeared to enhance recovery. Therefore, this study suggests that diure tics through sodium-volume depletion potentiate the effect of ACE inhi bitors on the kidney to cause decreased renal function.