[A case of polymyalgia rheumatica with improved steroid-responsibility after discontinuing carbamazepine]

A 70-year-old woman under anticonvulsive therapy with carbamazepine and valproate was diagnosed as polymyalgia rheumatica. She responded to the prednisolone therapy so poorly that she required high dose prednisolone and methotrexate, and it was difficult to reduce prednisolone. After discontinuing of carbamazepine, her steroid response improved immediately. Carbamazepine is known to induce hepatic enzyme CYP3A4 and alter metabolism of other drugs. In our case, the effect of prednisolone might have been reduced by carbamazepine. This case suggests more attention should be paid to the interaction between carbamazepine and prednisolone.