THE EFFECT OF SERUM POTASSIUM CONCENTRATION ON QUINIDINE TOXICITY

¹ Department of Medicine, Veterans Administration Research Hospital and Northwestern University Medical School, Chicago, Illinois

Quinidine gluconate was infused intravenously in anesthetized dogs until death, while serum quinidine, serum potassium and electrocardiograph (ECG) and arterial pressure were monitored. Control, hyperkalemic and hypokalemic animals were studied. Hyperkalemia did not significantly affect the intraventricular conduction disturbance produced by quinidine but did decrease survival time. Hypokalemia protected against the conduction prolongation from quinidine, but did not significantly prolong survival when compared to the control group. Despite the greater amounts of quinidine infused in the hypokalemic group than the hyperkalemic or control groups, the serum quinidine levels were not significantly different, suggesting that serum potassium influences the removal of quinidine from the blood. The serum quinidine was found to be a reliable index of severe quinidine intoxication.