benztropine and Hyperprolactinemia

Akathisia tends to develop as an early complication of antipsychotic treatment in a dose-dependent manner. Although withdrawal akathisia has been reported after the discontinuation or dose reduction of typical antipsychotic drugs, akathisia following atypical antipsychotic drug withdrawal remains a rare phenomenon.. A 24-year-old woman with an acute psychotic episode was admitted and initially treated with aripiprazole. The aripiprazole dose was titrated up to 30 mg/day over 9 days and maintained for the next 3 days; however, her psychotic symptoms persisted without change. She was switched to amisulpride, with the dose increased over 2 weeks to 1000 mg/day. Subsequently, although the patient's psychotic episode subsided, her serum prolactin levels increased markedly. After discharge, the amisulpride dose was increased to 1200 mg/day owing to auditory hallucinations and was maintained with quetiapine (100-200 mg/day) and benztropine (1 mg/day) for 13 weeks. Given the potential for hyperprolactinemia as a side effect, the amisulpride dose was reduced to 800 mg/day concurrently with the discontinuation of benztropine; however, these changes resulted in severe restlessness without other extrapyramidal symptoms. The withdrawal akathisia disappeared over 2 weeks after switching to aripiprazole (10 mg/day) with propranolol (40 mg/day) and the patient's prolactin levels had normalized after 6 months of aripiprazole monotherapy.. The present case highlights the potential for the development of withdrawal akathisia when the dose of amisulpride is tapered abruptly. Thus, a slow tapering and careful monitoring are recommended when switching from amisulpride to other antipsychotic drugs. Furthermore, this case suggests that changing the regimen to aripiprazole with propranolol may be a potential option for amisulpride withdrawal akathisia superimposed on pre-existing hyperprolactinemia.

Topics: Adult; Amisulpride; Antipsychotic Agents; Aripiprazole; Benztropine; Female; Humans; Hyperprolactinemia; Prolactin; Propranolol; Psychomotor Agitation; Psychotic Disorders; Young Adult