A Randomized Open Label Comparison of the Effects of Risperidone and Haloperidol on Sexual Function

Article excerpt

Objective: Sexual dysfunction in patients who take antipsychotics causes a decline in their quality of life and medication acceptance. Considering the restrictions in cross sectional design of many earlier researches, we used a clinical trial aimed at assessing sexual dysfunction by substituting Risperidone, an atypical antipsychotic drug, with Haloperidol, a typical one .

Method: This clinical trial was conducted on 51 patients who had been using Risperidone with a minimum dose of 2 mg/daily for at least 2 months. The patients were randomly divided into 2 groups. The first group continued taking Risperidone, whereas the second group was given Haloperidol. Sexual function prior to and after the drug substitution was assessed using a sexual questionnaire designed to assess four stages of sexual function .

Results: Compared to those who changed their medication to Haloperidol, the patients who remained on Risperidone therapy suffered from more sexual dysfunction, especially in their tendency towards having sexual activities (P= 0.01), post menstrual sexual activity (P= 0.002), and reaching orgasm in their sexual activities (P= 0.04); however in the Haloperidol group, no significant difference was observed before and after the change in medication .

Conclusion: Although Risperidone and Haloperidol can both disturb patients' sexual function, the side effects of Risperidone are stronger. Hence to prevent the decline of medication acceptance or irregular consumption by patients which may lead to possible relapse, substitution of Risperidone with another drug with fewer side effects on sexual activities is definitely to the advantage of the patients .

Key words: Adverse effects, Antipsychotic agents, Haloperidol, Risperidone, Sexual dysfunction

Iran J Psychiatry 2009; 4:116-119

One of the strongest predictors of patients' unwillingness for drug consumption is their experience of drug side effects. The major side effect of antipsychotic drugs in both sexes is sexual dysfunction which leads to the deterioration of quality of life and a decline in treatment acceptance by the patients. Hence considering the nature of sexual dysfunction and its vital role in the patients' quality of life and their treatment acceptance, selecting a drug with the least side effects should be a priority(1).

Literature reports that both typical and atypical drugs like Haloperidol and Risperidone can affect sexual function adversely (1,2).

The 2006 Knegtering et al study, conducted on 46 patients, compared the effects of Olanzapine and Risperidone on sexual function and reported less sexual dysfunction in patients using the latter(3).

In 2006, Dossendbachm et al simultaneously evaluated the effects of typical and atypical antipsychotics on the sexual function of schizophrenic patients among the patients from the schizophrenia study centers in Austria and Australia, and found that sexual dysfunction in schizophrenic patients leads to deterioration in their life quality and a decline in their treatment acceptance.

Following a one-year period of the treatment, sexual dysfunction was found to be remarkably higher in the Risperidone and Haloperidol groups as compared to the Olanzapine and Queitiapine groups (2). However, the Bobesj et al study conducted in the psychiatry ward of the Spanish Oviedo University-teaching hospital indicated that no meaningful/significant differences in side effects were found /observed between the longterm side effects of typical (Haloperidol) and atypical antipsychotic drugs, including Risperidone (4).

In 2003, in Scotland, Hunter et al, through a systematic review of the data from 1980 to 2002, concluded that Risperidone is more effective than Haloperidol in improving the positive and negative signs, thereby decreasing the possibility of relapse within the first year following the treatment. However, Risperidone had less sexual side effects compared to Haloperidol, demonstrating that Rispridone is more acceptable for treating patients with schizophrenia than Haloperidol (5). …