Tacrolimus in refractory patients with myasthenia gravis: coadministration and tapering of oral prednisolone.

We prospectively investigated therapeutic and adverse effects of tacrolimus in seven patients with myasthenia gravis (MG) who were resistant to conventional therapies or could not be treated with thymectomy because of complications. Within two months of initiation of tacrolimus all the patients subjectively showed improvement of clinical symptoms, while both the quantitative MG score for disease severity and MG-activities of daily living profile were significantly decreased (p<0.05) 3 and 6 months after commencement compared with before. Nine months after initiation and later, MG temporarily exacerbated in two patients with rapid tapering of oral prednisolone and one non-thymectomized one. This drug is useful in the treatment of refractory patients with MG irrespective of thymectomy, particularly in the early phase after commencement. When tacrolimus is additionally used for treatment of MG, preceding drugs, particularly corticosteroids such as oral prednisolone, should be carefully tapered if necessary in order to prevent clinical exacerbation.