A 74-year-old woman comes to the clinic to discuss frequent nocturnal leg cramps. She has been having calf cramps four to five times a week that occur when she is asleep. She does not have any major medical problems. Her only medication is famotidine, which she takes a few times a week for occasional GERD symptoms.
Her physical exam is normal.
What do you recommend to help prevent leg cramps?
a) Magnesium supplementation
b) Verapamil
c) Calf-stretching exercises
d) Hydroxychloroquine
e) Spironolactone
The correct answer here is to have the patient start calf-stretching exercises.
Nocturnal leg cramps are very common and frequently asked about by patients, occurring in 40% of patients over the age of 50. Patients’ sleep can be disturbed if the cramps occur frequently, and the resulting poor sleep can lead to fatigue and worsening quality of life.
The first step in helping patients is being certain of the diagnosis. The condition that has symptoms closest to nocturnal leg cramps is restless leg syndrome (RLS). Both nocturnal leg cramping and RLS occur at night. The most important differentiating point is that RLS symptoms are more continuous and, most important, improve with movement of the limb, especially brief periods of walking. Check a patient’s medication list first, as several medications can be triggers, with beta-agonists and potassium-sparing diuretics the most common causes (especially spironolactone).
Stretching exercises are the mainstay of preventive therapy. Hallegraeff and colleagues studied the effect of calf and hamstring stretching in 80 patients over age 55 who had nocturnal leg cramps and were not on any treatment. Half of the patients did calf and hamstring stretches at nighttime; the control group didn’t. Cramping frequency and severity was statistically significantly less in the stretching group. Tapper and colleagues randomly assigned 98 patients who had experienced more than four episodes of nocturnal leg cramps to stretching vs meditation. Both groups had a statistically significant reduction in cramp severity (P =.001).
Multiple treatments have been studied. For many years, quinine was the standard therapy offered until the US Food and Drug Administration banned it as an over-the-counter product in 1994 because of safety concerns. A Cochrane analysis in 2015 concluded that there is low-quality evidence that quinine (200-500 mg/d) significantly reduces cramp number and cramp days, and moderate-quality evidence that quinine reduces cramp intensity.
A recently published randomized controlled trial authored by Tan and colleagues supports the use of vitamin K2 for nocturnal leg cramps. A total of 199 patients were enrolled, with 103 randomly assigned to receive 180 µg/d of vitamin K2 and 96 receiving a matching placebo. During the 8-week intervention, the vitamin K2 group experienced a reduction in the mean weekly frequency of cramps to just fewer than one cramp per week, while the placebo group maintained mean weekly frequency of about 3.5 cramps per week. The between-group difference was statistically significant (P <.001).
Patients with cirrhosis frequently have bothersome nocturnal leg cramps. Vidot and associates conducted a small, randomized crossover trial of 30 patients with cirrhosis who had severe muscle cramps and who were treated with taurine. Patients had statistically significantly fewer and less severe cramps, as well as shorter duration of cramps, when they were taking 2 g of taurine (P =.03 for frequency and duration, P <.004 for intensity).
Magnesium is frequently prescribed for muscle cramps, but a Cochrane review concluded that it is unlikely that magnesium supplementation provides clinically meaningful cramp prophylaxis to older adults experiencing skeletal muscle cramp.
Pearl: The best option for muscle cramp prevention is stretching exercises. Vitamin K2 supplementation looks like a promising and safe option.
Dr Paauw is professor of medicine in the Division of General Internal Medicine at the University of Washington, Seattle, and serves as third-year medical student clerkship director at the University of Washington. Contact him at dpaauw@uw.edu.