Combination Therapy With Risperidone and High-Dose Melatonin Is Effective Despite Reversible Side Effects Including Breast Budding.

Melatonin is commonly used to treat sleep disorders. Regardless of the prolactin level elevation induced by melatonin administration, breast budding is not known to develop as a result of this treatment. A 10-year-old boy presented to our outpatient clinic with restlessness and sleep disorders. Risperidone (0.5 mg/day) and melatonin (1 mg/day) were orally administered. His daytime concentration improved after increasing the melatonin dosage to 2, 3, and 4 mg/day every 2 weeks, although his nighttime awakenings did not completely improve. After continuing high-dose melatonin treatment for one month, the patient experienced pain in his left mammary gland and developed breast budding. However, it disappeared promptly after the discontinuation of melatonin. Risperidone and high-dose melatonin administration effectively reduced restlessness. Administration of risperidone and high-dose melatonin may cause breast budding; however, breast budding is reversible upon the discontinuation of melatonin, and we suggest that clinicians prescribe medication as needed to improve these symptoms.