Effect of indomethacin on acute potassium tolerance

Nonsteroidal anti-inflammatory drugs are believed to impair potassium tolerance in both humans and experimental animals. We evaluated plasma potassium response to an acute potassium chloride load (75 microEq/100 gm body wt) in rats pretreated with indomethacin (10 mg/kg body wt). The increment in plasma potassium concentration in the indomethacin-treated group was significantly higher than that in the control group. In a subset of anuric animals treated with indomethacin, the change in plasma potassium concentration after potassium chloride infusion was similar to that in controls. We conclude that indomethacin disrupts acute potassium tolerance. The abnormality may be related to renal rather than extrarenal mechanisms.