Effects of carbamazepine on pituitary responsiveness to luteinizing hormone-releasing hormone, thyrotropin-releasing hormone, and metoclopramide in epileptic patients.

Pituitary responsiveness to luteinizing hormone-releasing hormone (LH-RH), thyrotropin-releasing hormone (TRH), and metoclopramide (MC) was studied in 40 epileptic patients (24 men and 16 women) receiving carbamazepine (CBZ) treatment and in 29 (20 men and 9 women) untreated epileptic patients. Mean basal concentration of serum LH was significantly lower in the CBZ-treated female patients than in untreated female patients. The response of LH to LH-RH was also blunted in CBZ-treated female patients. No differences were found in basal or stimulated LH levels between the two groups of male patients. Nevertheless, the mean basal concentration of serum prolactin (PRL) was lower and the response of PRL to TRH was higher in male patients treated with CBZ. No differences were found in serum levels of follicle-stimulating hormone (FSH) or in responses of FSH to LH-RH between the CBZ-treated and untreated patients. These results indicate that CBZ has effects on pituitary responsiveness.