Clinical efficacy of tacrolimus in prednisone-dependent patients with generalized myasthenia gravis

Objective　To evaluate the efficacy of tacrolimus in patients with prednisone-dependent generalized myasthenia gravis (MG). Methods　A total of 74 patients with prednisone-dependent generalized MG received either tacrolimus (FK506) (n=34) or azathioprine (n=40) for more than 12 months. The daily dosage and adverse reaction of tacrolimus or azathioprine used in these two groups were recorded, and the therapeutic effect of the drugs and the clinical scores of MG were evaluated and compared between the two groups before treatment and at 1, 3, 6 and 12 months after treatment. Results　Compared with that of before treatment (18.2±9.1), clinical relative scores of MG decreased significantly in tacrolimus group at 1, 3, 6 and 12 months after its treatment (13.4±6.5, 10.7±4.6, 8.7±3.7 and 5.3±2.1, respectively) (P<0.01). While in azathioprine group, the significant differences in efficiency appeared only 6 and 12 months after azathioprine treatment (P<0.05). The total clinical efficacy (clinical relative score ≥25%) in tacrolimus group were 65.3%, 77.6%, 81.2% and 85.8%, respectively at 1, 3, 6 and 12 months after treatment, and it was significantly higher than that in azathioprine group (12.3%, 25.4%, 56.7% and 75.6%, respectively). Prednisone decrement rate in tacrolimus group was 8.8%, 32.4% and 70.6%, respectively at 3, 6 and 12 months after treatment, and the rate of prednisonerelated adverse effects decreased from 94.1% at baseline to 14.7% at the final visit (P<0.01). Conclusion　The therapeutic effect of tacrolimus is clearly superior to that of azathioprine for the prednisone-dependent generalized MG patients, and it significantly reduces the dependence of patients on prednisone. DOI: 10.11855/j.issn.0577-7402.2015.01.10