Long-term naltrexone treatment modifies luteinizing hormone secretory amplitude in polycistic ovary syndrome

Objective: To evaluate the neuroendocrine effect of naltrexone in the long-term treatment of polycystic ovary syndrome. Methods: The chronobiological secretory characteristics of the pituitary hormones FSH, LH, PRL, and cortisol were investigated over a period of 8 hours in a group of polycystic ovary syndrome patients before and after treatment with naltrexone (50 mg per os daily for 28 days). Results: No significant changes in integrated LH mean values and mean LH pulse frequency were found, whereas the mean LH pulse amplitude was significantly lower (p<0.05) after 28 days of naltrexone therapy. The characteristics of pulsatile FSH, PRL and cortisol secretory patterns were not significantly different before and after treatment with naltrexone. Conclusion: This study shows that long-term naltrexone therapy reduces the LH pulse amplitude probably through central and peripheral mechanisms without affecting the overall LH secretion. Thus, naltrexone can represent a useful tool in the clinical management of polycystic ovary syndrome.