A randomized controlled trial of quinidine in the treatment of cirrhotic patients with muscle cramps.

In an attempt to evaluate the effect of quinidine in the treatment of patients with cirrhosis and muscle cramps, 31 cirrhotic patients with muscle cramps were randomly divided into two groups and given orally 400 mg of quinidine sulfate per day or placebo, respectively. Baseline clinical and laboratory data for these two groups were similar. Four weeks after oral administration of quinidine, the number of cramps significantly decreased from 14.4 +/- 1.7 (mean +/- S.E.) to 4.4 +/- 1.1 episodes (p less than 0.0001), but it remained unchanged in the placebo group (from 11.8 +/- 1.0 to 11.5 +/- 1.5 episodes, p greater than 0.05). In addition, 88% of the 16 patients on quinidine and 13% of the 15 patients on a placebo showed a greater than 50% reduction in the number of cramps during a 4-week treatment period (p less than 0.0001). The peak and trough serum levels of quinidine in patients having received quinidine for 2 weeks were 1.3 +/- 0.1 and 0.7 +/- 0.1 mg/l, respectively. There was a significant relationship between serum quinidine concentrations and attenuation of cramps. No significant adverse effect was observed during the study, except for five (31%) patients who developed mild diarrhea after quinidine therapy. Diarrhea subsided spontaneously or was controlled by medications without the interruption of quinidine therapy. It was concluded that quinidine is a safe and effective drug for the treatment of cirrhotic patients with muscle cramps.