Changes in Serum Prolactin Levels after the Administration of Risperidone in Schizophrenic Patients: Gender Difference

Kim, Kwang Soo; Sung, Yang Sook; Chae, Jeong Ho; Bahk, Won Myong; Lee, Chung Tai; Lew, Tae Yul

Abstract

OBJECTIVE
In spite of being an atypical antipsychotic which has serotonergic(5HT2) biocking activity in addition to the dopaminergic(D2) antagonistic action, risperidone elevates serum prolactin level. Hyperprolactinemia secondary to neuroleptic treatment have an obvious impact on fertility. We investigated the prolactin response after oral administration of risperidone and compared the prolactin responses between male and female subjects. METHOD: Subjects included 10 male and 7 female patients who met DSM-IV criteria for schizophrenia(n=17), Blood samples(4 ml/sample) were taken on the 1st, 2nd, 3rd, 14th, 28th and 42nd days, twice, at 8:00 AM and at 10:00 AM in the morning after an overnight fast. The daily medication was administered after the first blood sampling at 8:00 AM. After baseline sampling, the same dose of risperidone was administered to each patient until the end of the 3rd day. The dose of risperidone was then decided by clinical evaluation. Serum prolactin concentrations were measured by standard double-antibody radioimmunoassay.
RESULTS
Administration of risperidone significantly increased serum prolactin levels (p<0.05). After administration of risperidone, the elevations of serum prolactin level in women was significantly higher than those in men (p<0.05). There were significant reductions in positive symptom stores (21.7+/-.8, vs 11.4+/-.0) and negative symptom score (20.5+/-.2, vs 14.6+/-.8), general symptom store (44.3+/-.4, vs 30.9+/-.0) of PANSS by risperidone administration for 6 weeks(p<0.05). All patients developed hyperprolactinemia and one of the ten men developed women developed menstrual disturbance during observation period.
CONCLUSIONS
This study suggests that administration of risperidone results in a significant increase of prolactin and the elevation of serum prolactin levels were significantly higher in women, therefore clinicians should be vigilant to possible reactions in female patients with psychotic symptoms upon treatment with risperidone.