Is it safe to use statins in patients with myasthenia gravis?

This Practice Point commentary discusses a retrospective study by Oh et al. in which the consequences of using statins in patients with myasthenia gravis (MG) were examined. Out of 170 patients with MG seen at a single hospital center during a 2.5-year period, 54 used statins. Six of these patients reported a worsening of MG symptoms within 8 weeks after receiving statins; in two cases the worsening was associated with a confirmed increase in serum acetylcholine receptor antibody concentration. A further seven patients retrospectively reported temporary muscle aching during the first 8 weeks after statin treatment. This effect was less clearly attributable to the drugs. The effects of statins on MG symptoms were believed to be mediated by the immune system. Statins should be used for the same indications in patients with MG as in those without the condition. However, patients with MG should be informed about the possibility of MG exacerbation, and the statins should be withdrawn if this occurs.