Retrograde Ejaculation Associated With Paliperidone Palmitate: A Case Report.

OBJECTIVES: Retrograde ejaculation is a rare but distressing adverse effect of antipsychotic treatment, primarily mediated by alpha-1 adrenergic receptor antagonism. While this complication has been widely reported with risperidone, reports associated with paliperidone palmitate are extremely limited. This report aims to present a case of paliperidone palmitate-induced retrograde ejaculation and to highlight its clinical implications. METHODS: This report describes a 49-year-old male who developed retrograde ejaculation during treatment with paliperidone palmitate. Clinical evaluation, including urological assessment, was conducted to exclude organic causes. The temporal relationship between medication exposure, dose adjustment, and symptom progression was carefully assessed. RESULTS: Retrograde ejaculation emerged under paliperidone palmitate monotherapy, persisted despite dose reduction, and resolved only after discontinuation and switch to aripiprazole. No organic etiology was identified. Partial improvement was observed during cross-titration, with complete resolution following discontinuation. CONCLUSIONS: Paliperidone palmitate can induce retrograde ejaculation despite its lower alpha-1 adrenergic affinity compared with risperidone. This adverse effect may be underrecognized in clinical practice and can contribute to treatment nonadherence. Proactive assessment and appropriate treatment modification are essential to improve clinical outcomes.