Paliperidone as an Alternative for Risperidone in a Case of Schizophrenia With Retrograde Ejaculation

To the Editor: Risperidone is an atypical antipsychotic agent. Compared with other antipsychotics, risperidone is a potent α₁ adrenoreceptor antagonist, with a high affinity (Ki of 0.69).¹ There are specific adverse effects of this property. Significant among them is retrograde ejaculation.^2–5 The impact of risperidone, a strong α₁-receptor antagonist, on the adrenergic system might induce retrograde ejaculation by altering sympathetic tonus, allowing semen to go retrograde into the bladder during ejaculation. The management of antipsychotic drug-induced sexual dysfunction is primarily directed toward avoiding the mechanism of the adverse effect, whether it is prominent dopamine blockade, elevated prolactin levels, or α-adrenergic blockade.⁴ Here, a case of risperidone-induced retrograde ejaculation that was successfully managed with paliperidone (9-OH risperidone) is presented.

“Mr. A,” a 29-year-old man, was brought to the psychiatry outpatient department with a history of abnormal behavior for the past 8 months. Initially, his mother noted that he was becoming irritable and aggressive without any reason. He was expressing persecutory and referential ideas about his sister. Gradually, it was noted that his interactions with others had decreased. His occupational functioning deteriorated in the form of poor quality of work and absenteeism. During the next 2 months, he was locking himself inside his room for long hours. He had bizarre delusions and derogatory/commanding-type auditory hallucinations. A diagnosis of paranoid schizophrenia was made. His physical examination was normal. He was started on risperidone 2 mg and titrated up to 3 mg bid. In the next month, he showed significant improvement. After 6 weeks, he reported after defaulting on drugs for about a week. He had stopped medication because he was having orgasms without ejaculation on masturbation. He was highly distressed about this symptom. His serum prolactin level was 330 mI/L, within normal limits. Analysis of his post-orgasmic urine showed a significant number of motile sperms. He was diagnosed with risperidone-induced retrograde ejaculation. He was not willing to take the same medication, even at a lower dose. He also had started hearing the commanding voices on and off again. It was clinically a difficult decision to withhold risperidone, since it had helped him very well. The psychotic symptoms might resurface until another drug takes over its action. So it was decided in this case to prescribe an alternative antipsychotic that has a (nearly) similar pharmacokinetic and pharmacodynamic profile.^1,6 He was started on paliperidone 3 mg, increased to 9 mg. He was followed up for the next 6 months. His psychotic symptoms were under control. Most importantly, he was able to have a normal orgasm and ejaculation during this period. He was very comfortable in continuing the medication.