Lack of changes in serum prolactin, FSH, TSH, and estradiol after melatonin treatment in doses that improve sleep and reduce benzodiazepine consumption in sleep-disturbed, middle-aged, and elderly patients

An open pilot study on the safety and efficacy of melatonin in the treatmen t of insomniac patients was conducted in 22 subjects (16 females), mean +/- S.D. age 60.1 +/- 9.5 years. All patients received 3 mg of gelatin melaton in capsules per os daily for 6 months, 30 min before expected sleep time. T wenty of 22 patients were on benzodiazepine treatment and they continued th is treatment for part of or for the entire melatonin administration period. Serum concentrations of prolactin, follicle-stimulating hormone (FSH), thy roid-stimulating hormone (TSH), or estradiol were measured by radioimmunoas say (RIA) in morning samples at the beginning and after 6 months of melaton in administration, and standard clinical laboratory tests for blood compone nts were performed. Urinary 6-sulphatoxymelatonin (aMT6s) excretion was mea sured by RIA before treatment. Serum concentrations of prolactin, FSH, TSH, or estradiol did not exhibit changes after 6 months of melatonin administr ation, nor were any indications of hematologic or blood biochemistry altera tion found. Melatonin augmented significantly the quality and duration of s leep, and decreased sleep latency and the number of awakening episodes, as assessed from sleep logs filled by the patients (first 21 days) and from st ructured interviews performed by incumbent physicians (up to 6 months). Est imates of next-day function (i.e., alertness in the morning and during the day) also improved significantly during melatonin treatment. The observed e ffect lasted for the entire period examined (up to 6 months), with 22 out o f 22 patients showing improved sleep at the end of treatment. The urinary e xcretion of aMT6s before starting administration of melatonin correlated ne gatively and significantly with age, but not with the intensity of sleep th e disorder or the outcome of treatment. In 13 of 20 patients taking benzodi azepines together with melatonin, benzodiazepine use could be stopped, and in another four patients, benzodiazepine dose could be decreased to 25-66% of the initial dose. The results of this open, subacute administration tria l indicate that melatonin is a safe and useful treatment for sleep disturba nces in middle-aged or elderly patients, either by itself or together with benzodiazepines.