Low-dose clozapine-induced retrograde ejaculation.

Abstract

Retrograde ejaculation (RE) is the absence of ejaculation despite presence of orgasm. The reason for a large number of RE cases is medications used in treatments. Very few RE cases have developed secondary to the use of clozapine. We describe a case in which clozapine induced RE. Our patient, Mr M, was aged 31 years. He had undergone treatment and follow up for schizophrenia for approximately 5 years. Due to the deterioration of drug compliance, the patient suffered somatic delusions, grandiose delusions, and persecution delusions and was hospitalized. Clozapine treatment was started at a dose of 25 mg/day and we increased the dose gradually. Complete blood count readings were followed during the course of disease, and no anomaly was found. At day 20 of hospitalization, the clozapine dose was increased to 200 mg/day. Three days after the dose of 200 mg/day was reached, the patient started to define urologic problems. On the laboratory work up, blood prolactin level was within normal limits. The patient could not provide sperm for laboratory work up; however, on the urinalysis after orgasm, sperm cells were seen. No pathology was found in the patient's urinary system. The symptoms defined by the patient were assessed to be consistent with RE. The patient's clinical picture of RE was assessed as being due to use of clozapine. It was decided that clozapine treatment should be discontinued after being gradually decreased and paliperidone treatment should be started instead. During the follow-up period, clozapine was totally stopped and the patient was shifted to paliperidone treatment. The clinical picture of the patient's RE ameliorated. The patient continues follow-up treatment. Clozapine is known as a safely used antipsychotic regarding sexual side-effects amongst atypical antipsychotics, as it has relatively few side-effects on sexual functions, its effect on the prolactin level is limited, and it positively affects social functionality.1 Very few cases of clozapine-induced RE have been reported.2, 3 However in the present case, RE was induced by a lower dose of clozapine than has previously been reported. Despite the occurrence of RE with clozapine in this patient, there may be a few reasons for not having RE with paliperidone. First, the affinity of clozapine to alpha-1 adrenergic receptors is higher than that of paliperidone.4 Second, clozapine and paliperidone may differ in their affinities to 5HT1A and 5HT2C receptors, which are thought to be closely related to ejaculation. Third, individual differences may play a role in susceptibility to RE. The patient gave informed consent, and his anonymity has been preserved. The authors report no conflict of interest.