Hyperkalemia Induced by the Sequential Administration of Metoprolol and Carvedilol

Abstract

This report describes the occurrence of asymptomatic hyperkalemia induced by the sequential administration of metoprolol and carvedilol in an 81-year-old man with type II diabetes and stable stage III renal insufficiency. The potassium level rose to 5.6–5.7 mEq/L with metoprolol and normalized when the agent was discontinued. However, the potassium level rose again to 5.6 mEq/L after the administration of carvedilol but the level normalized by halving the dose. The observations of hyperkalemia induced by two different β-blocker drugs in the same patient confirm that this side effect is common to all β-blocker drugs.