Abstract
Objective: Hyperprolactinemia is an adverse effect, which is related with the use of antipsychotics. All typical antipsychotics are considered to increase serum prolactin levels. Compared with typical antipsychotics, most of the atypical antipsychotics have a reduced tendency for increasing serum prolactin levels. However, effects of all atypical antipsychotics on serum prolactin levels are not always similar. In the present study, we aimed to compare short-term effects of risperidone and paliperidone, which are two similar atypical antipsychotics in terms of hyperprolactinemia and its associated symptoms.
Methods: In this study, we screened data of female patients with diagnosis of schizophrenia and other psychotic disorders, bipolar disorder and who were treated with risperidone or paliperidone. The patients who had adequate sociodemographical and clinical data and who had screened in terms of prolactin levels before and fourth week of the treatment were included to study.
Results: Forty-two patients have been treated with risperidone and 36 patients have been treated with paliperidone. Treatment groups were similar in terms of sociodemographic variables. The mean values of serum prolactin levels were significantly increased after four weeks of treatment in both groups (p<0.001). The discontinuation rates because of menstrual irregularities, galactorrhea, sexual dysfunction in risperidone and paliperidone groups were 11.9% and 30.6% respectively, and the rate was significantly higher in paliperidone group (?2=4.13, p=0.04).
Conclusion: We suggest that beside its benefits and some superiorities compared to risperidone, paliperidone has no advantage over risperidone in terms of hyperprolactinemia and its associated symptoms. We also suggest that female patients should be monitorized regulary in terms of hyperprolactinemia and its associated symptoms while they are being treated with paliperidone. To our knowledge, the present study is the first to compare and demonstrate the effects of paliperidone and risperidone on serum prolactin levels in Turkey. Further studies with larger sample size are needed to highlight the short term and long term effects of paliperidone on serum prolactin levels in female patients.

Key words: risperidone, paliperidone, prolactin