https://immattersacp.org/weekly/archives/2011/12/20/4.htm

LABAs but not statins associated with leg cramps

Patients who begin taking a long-acting beta2-agonist or certain kinds of diuretics may have an increased risk of experiencing nocturnal leg cramps, a new study concluded.


Patients who begin taking a long-acting beta2-agonist (LABA) or certain kinds of diuretics may have an increased risk of experiencing nocturnal leg cramps, a new study concluded.

The study used a database of prescribing information for about 4 million residents of British Columbia, Canada. Researchers looked at adults 50 years or older that had an index prescription for a diuretic, a statin or a LABA in 2000 to 2008 and then assessed the rate of quinine prescriptions (which they considered a marker for cramp treatment) for these patients in the years preceding and following the index prescription. The results were published online Dec. 12 by Archives of Internal Medicine.

Beginning treatment with a LABA was associated with the greatest increase in quinine use. The adjusted sequence ratio was 2.42, indicating that patients were 142% more likely to receive quinine in the year after initiating LABA treatment than the year before (P<0.001). Diuretics as a class also increased risk (adjusted sequence ratio, 1.47; P<0.001), but differences existed among the diuretic subclasses in their risk for cramps. Potassium-sparing diuretics had the greatest association with quinine use (adjusted sequence ratio, 2.12; P<0.001), followed by thiazide-like diuretics (adjusted sequence ratio, 1.48; P<0.001). Loop diuretics did not pose a statistically significantly increased risk (adjusted sequence ratio, 1.20; P=0.07). Statins were also not found to increase risk (adjusted sequence ratio, 1.16, P=0.004).

Overall, the study found that 60.3% of quinine users in the database had received at least one of the medications that were found to increase cramp risk (LABAs, potassium-sparing diuretics or thiazide-like diuretics) during a 13-year period. The authors noted that these findings extend and support the existing evidence linking these drugs to muscle cramping, which previously had been largely anecdotal.

If patients' cramps could be eliminated by nonuse of these drugs, the number needed to treat by discontinuing the drugs would be 1.7 for LABAs and 3.1 for thiazides, the authors calculated. They concluded that physicians should be aware of the epidemiological association between these drugs and cramp treatment, and be mindful that use of the drugs could worsen patients' nocturnal leg cramps.