Statin-Associated Myasthenia Gravis

A few recent individual case reports have suggested that a myasthenic syndrome may be associated with statin treatment, but this association is not well described. We report 4 patients who developed symptoms of myasthenia gravis within 2 weeks of starting treatment with a statin drug. In 1 case the drug appears to have exacerbated underlying myasthenic weakness, whereas in the other 3 cases, de novo antibody formation appears to be most likely. In each case, some degree of recovery followed discontinuation of the statin medication. Abbreviations: AChR = acetylcholine receptor, EMG = electromyogram, HMG-CoA = 3-hydroxy-3-methyl-glutaryl-CoA.