Aripiprazole for the treatment of duloxetine-induced hyperprolactinemia: A case report

It is well known that aripiprazole co-treatment effectively reduces antipsychotic-induced hyperprolactinemia. However, the effectiveness of aripiprazole to treat high prolactin levels induced by antidepressant drugs with serotoninergic activity, such as duloxetine, remains unknown.

An 18-year-old female diagnosed with major depressive disorder (MDD) was treated with 100 mg sertraline once daily. After two weeks, galactorrhoea was observed. Blood biochemical tests revealed an elevated serum prolactin level of 241 ng/mL. Physiological causes and additional potential pathological causes were ruled out. Therefore, sertraline was cross tapered with mirtazapine. Galactorrhoea ceased, but the side-effect of sedation prompted a switch to 40 mg duloxetine twice daily. After two weeks, the patient developed menstrual irregularities and milky discharge concomitant with a serum prolactin level of 205 ng/mL. As a result, duloxetine was decreased to 60 mg once daily, and aripiprazole was initiated at 2.5 mg daily and titrated to 5 mg daily. Two weeks after the initiation of dual therapy, galactorrhoea stopped, and prolactin levels decreased to 118 ng/mL. After eight weeks, prolactin levels decreased to 39 ng/mL, and menstruation returned to normal. After antidepressant therapy finished, prolactin levels normalized to 19 ng/mL.

The case suggests that adjunctive aripiprazole may be useful as a treatment option for duloxetine-induced hyperprolactinemia in MDD.