A risperidone-induced prolactinoma resolved when a woman with schizoaffective disorder switched to ziprasidone: a case report.

Antipsychotic drug therapy, e.g., risperidone, can be associated with endocrine abnormalities, including an increase in serum prolactin level (sPrl) due to a drug-induced benign pituitary tumor (prolactinoma). A few case reports have noted a resolution of hyperprolactinemia and prolactinoma after cessation of risperidone treatment. We report a similar finding for a woman with schizoaffective disorder, manic type.Due to a neurological disorder involving the tongue (tardive dyskinesia), a woman with schizoaffective disorder switched from 50mg thioridazine after 21 years to 2mg of risperidone at bedtime for 10 years. Elevated sPrl was noted in June and August 2005 (83.8 and 100.1µg/L; normal: 3.4-24.1µg/L) and a cranial magnetic resonance imaging scan showed evidence of a small area of decreased signal in the pituitary gland consistent with a microadenoma. The subject transitioned slowly to ziprasidone and off risperidone in October and November of 2005. The prolactinoma completely resolved with the switch to ziprasidone. It is recommended that sPrl be measured annually in patients taking antipsychotic drugs to test for any indication of pituitary prolactinoma that could suggest the need to switch the primary treatment to another drug.