Meta-analysis of efficacy of quinine for treatment of nocturnal leg cramps in elderly people.

OBJECTIVE To assess quantitatively the efficacy of quinine (as quinine sulphate) compared with placebo in the treatment of nocturnal leg cramps. DESIGN A meta-analysis of six randomised, double blind, crossover trials. SETTING Randomised trials that were available as of April 1994. SUBJECTS A total of 107 general ambulatory patients who suffered from regular nocturnal leg cramps from six clinical trials. RESULTS Data from individual patients were used to calculate point estimates and 95% confidence intervals for each of the outcome measures reported by these studies. Treatment with quinine resulted in a significant reduction in the number of cramps for a four week period compared with placebo (8.83 fewer cramps; 95% confidence interval 4.16 to 13.49). Treatment with quinine reduced the number of nights with cramps by 27.4% (24.0% to 30.8%) compared with placebo. Treatment did not produce a significant change in the severity or duration of individual nocturnal leg cramps. Side effects were uncommon. CONCLUSIONS The results indicate that quinine can prevent nocturnal leg cramps in general ambulatory populations. Given the possible serious side effects of treatment with quinine, the benefits and risks in patients taking this drug should be closely monitored.