Nephrotoxicity and hyperkalemia in patients with acquired immunodeficiency syndrome treated with pentamidine

Recently, the use of pentamidine has risen because of its efficacy in managing patients with acquired immunodeficiency syndrome (AIDS) and Pneumocystis carinii infection. We undertook a retrospective analysis of the charts of 22 patients with AIDS given pentamidine when they were hospitalized over a two-year period.

Collectively, these 22 patients were admitted 28 times during this period and received a total of 23 courses of pentamidine. During five of these admissions, pentamidine was not given. The duration of therapy ranged from five to 33 days (mean: 13.4 days). Three admissions were excluded because of insufficient laboratory data or concomitant use of therapies that could affect the parameters being studied.

In 19 of the remaining 20 admissions, the patients treated with pentamidine were observed to have elevations of potassium (5.1 to 8.7 mEq/L), creatinine (1.5 to 11.8 mg/dL), and blood urea nitrogen (27 to 183 mg/dL), and a decrease in serum bicarbonate (14 to 21 mEq/L). Of the 19 patients exhibiting these abnormalities, most required sodium polystyrene sulfonate and two required dialysis. During the admissions when pentamidine was not given, hyperkalemia was not observed. After discontinuation of pentamidine therapy, these metabolic derangements normalized in all patients except for one who died while still in acute renal failure. Four patients received more than one course of therapy and upon reinstitution of pentamidine treatment, the same metabolic abnormalities recurred.

In conclusion, pentamidine is more nephrotoxic in patients with AIDS than previously reported in other subjects and can cause life-threatening hyperkalemia.