Magnesium for the treatment of nocturnal leg cramps: a crossover randomized trial.

Abstract

BACKGROUND:

Nocturnal leg cramps are a common health problem in the ambulatory setting. Our objective was to evaluate the efficacy of magnesium in the treatment of nocturnal leg cramps.

METHODS:

Our study was a crossover randomized double-blind placebo-controlled trial. We included patients from a large university-based ambulatory clinic in Buenos Aires, Argentina, with at least 6 cramps during the previous month. A total of 93 subjects took part in a 4-week washout period with placebo. Those who were still eligible (n = 45) were randomized to receive either (1) an oral dose of 900 mg magnesium citrate twice daily for 1 month, followed by a matching placebo for 1 month, or (2) the placebo first, followed by magnesium. Both groups had a 4-week washout period with placebo between each treatment month. Forty-two patients completed the 4-month study. The main outcome was the number of nocturnal leg cramps, and the secondary outcomes were duration, severity, and sleep disorders caused by those cramps.

RESULTS:

There were no significant differences between magnesium and placebo in any of the evaluated outcomes. The mean number of cramps was 11.1 (standard deviation [SD] +/- 7.3) for placebo versus 11.8 (SD +/- 7.6) for magnesium (P = .59). We observed a significant period-effect bias: All patients improved over time regardless of the treatment sequence they received.

CONCLUSIONS:

Magnesium was not effective for the treatment of nocturnal leg cramps. The period-effect bias probably occurred because of a combination of the natural history of this condition, a regression to the mean, and a true placebo effect.

• Authors: R Frusso, M Zárate, F Augustovski, A Rubinstein
• Journal: The Journal of family practice (J Fam Pract) Vol. 48 Issue 11 Pg. 868-71 (Nov 1999) ISSN: 0094-3509 [Print] United States
• PMID: 10907623 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Magnesium

Topics

• Adult
• Aged
• Aged, 80 and over
• Cross-Over Studies
• Double-Blind Method
• Female
• Humans
• Magnesium (therapeutic use)
• Male
• Middle Aged
• Muscle Cramp (complications, drug therapy)
• Sleep Wake Disorders (etiology)
• Treatment Outcome