Risperidone-induced polydipsia and polyphagia associated with galactorrhea, abdominal pain, and rapid weight gain in an adolescent Hispanic female

A 15-year-old Hispanic female was started on risperidone for new-onset psychosis. The patient responded well to the gradual dose increase but developed rapid weight gain secondary to polydipsia and polyphagia. She also began complaining of nipple discharge and griping abdominal pain on the left lower quadrant by the third week of treatment. Her prolactin level escalated to three times normal with a weight gain of 12 pounds in 16 days. Risperidone was switched to another antipsychotic. Her prolactin level then dropped to a normal level within 7 days and she lost 7 pounds in the next 2 weeks. Her abdominal pain, galactorrhea, polydipsia, and polyphagia subsided within the first few days of the cessation of risperdione.