The effects of long-term carbamazepine, phenobarbital and valproic acid therapy on thyroid and parathyroid functionsErcan Uğur, Cihan Meral, Ferhan Karademir, Selami Süleymanoğlu, Seçil Aydınöz, İsmail Göçmen.
Carbamazepine, phenobarbital and valproic acid are used as antiepileptic drugs in many types of epilepsy. Although these antiepileptic drugs are well tolerated, it is known that they have some side effects on endocrine system. In this study, we investigated the effects of carbamazepin, phenobarbital and valproic acid treatment on thyroid and parathyroid functions of 120 cases (58 female and 62 male with ages ranging between 5 months to 14 years) followed-up with the diagnosis of epilepsy, and compared these effects with those of a control group. Complete blood count, serum levels of calcium, phosphorus, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, free triiodothyronine, free thyroxine, thyroid stimulating hormone, parathyroid hormone and serum drug concentrations were measured in all cases. Carbamazepin and phenobarbital except for valproic acid significantly decreased free thyroxine levels. Free triiodothyronine and thyroid stimulating hormone levels did not differ significantly between the study and control groups. Parathormone levels significantly increased in the groups of phenobarbital and carbamazepine when compared to the control group. No significant differences were observed among the groups regarding serum calcium and phosphorus levels. We conclude that thyroid and parathyroid functions of patients using carbamazepine and phenobarbital for a long time should be regularly monitored.
Phenobarbital, carbamazepine, parathyroid, thyroid, valproic acid