Can clinical parameters of patients, sans serum prolactin measurement, identify amenorrhea associated with risperidone use? Results from a cross-sectional analytical study

Background: Risperidone is a second-generation antipsychotic, which exerts its action by antagonizing dopamine (D2) and serotonin (5-HT2A) receptors. Amenorrhea is a common adverse effect observed in risperidone. Risperidone blocks the dopamine receptor of lactotroph cells of the pituitary gland, resulting in loss of the inhibitory effect of dopamine on prolactin. The resultant hyperprolactinemia decreases estrogen through its impact on the pulsatile secretion of gonadotropins and ovarian follicular growth leading to amenorrhea. Identifying the associated clinical parameters will aid in predicting the occurrence of amenorrhea in patients on treatment with risperidone, especially in a setting devoid of prolactin estimation. The objective of this study was to compare the clinical profile of patients with and without risperidone-induced amenorrhea. Methodology: A cross-sectional comparative study was done in a tertiary care hospital. A total of 30 female patients on risperidone who developed amenorrhea were recruited, and age-matched patients on risperidone without amenorrhea were taken as controls. The clinical parameters of the groups were compared using the Mann–Whitney U-test. Binary logistic regression was used to predict the clinical predictors associated with risperidone-induced amenorrhea. Results: The amenorrhea group had a significantly longer duration of untreated psychosis (DUP) (P = 0.011), duration of total treatment (P = 0.003), and duration of treatment exclusively with risperidone (P = 0.002). No significant differences were noted in the dose of risperidone (P = 0.570) and the diagnosis (P = 0.455) between the groups. However, the regression test did not confer any risk due to any clinical parameters. Conclusion: Individuals who developed amenorrhea had a longer DUP and a longer duration of treatment exclusively with risperidone.