6555 Cabergoline-induced psychiatric symptoms in a patient with a pituitary macroadenoma

Abstract Disclosure: G.S. Patel: None. J. Prater: None. Cabergoline is a long-acting dopamine agonist that is used for the treatment of hyperprolactinemia, especially in pituitary macroadenomas. It reduces the levels of prolactin (PRL) but is also effective in reducing the tumor size and allows patients to avoid undergoing surgical resection of the mass. It commonly causes side effects such as abdominal pain, bloating, dizziness, and headaches. It rarely can cause new onset psychological side effects or an exacerbation of pre-existing mood and behavioral disorders. We present the case of a male on cabergoline therapy who had new-onset psychiatric symptoms that persisted even after treatment was discontinued. The patient is a 40-year-old male who was found to have a pituitary macroadenoma measuring 2.2 x 1.8 x 1.6 cm on brain MRI after a one-year history of headaches, dizziness, and hearing loss. His vital signs and physical examination were unremarkable. Laboratory investigations revealed a PRL of 1,072 ng/mL. He was started on cabergoline 0.25 mg twice a week which reduced levels of PRL to 465.3 ng/dL. Throughout the next year, his PRL levels remained persistently elevated to >100 ng/dL and the cabergoline dose was steadily increased to 1 mg three times per week. About a year into treatment he began experiencing significant emotional lability, a tendency to cry, and bursts of temper which required the addition of multiple psychiatric medications. After two years of continued psychiatric symptoms, there was an attempt to both reduce cabergoline doses and switch to escalating doses of bromocriptine, both of which resulted in a reduction of psychiatric symptoms but also significant increases in PRL levels. The patient’s mood symptoms returned shortly after switching back to cabergoline, especially with increased doses. He eventually underwent trans-sphenoidal resection for his treatment-resistant pituitary macroadenoma. He was taken off cabergoline before surgery with a significant reduction in his mood symptoms but continues to require psychiatric medications for lasting emotional lability. Although rare, psychiatric side effects of cabergoline have been documented and must be addressed if a patient develops them while receiving treatment. Our patient had a severe presentation of mood symptoms from cabergoline therapy that required multiple psychiatric medications in escalating doses to control. It not only affected his quality of life but also resulted in long-term consequences. It is recommended that patients with similar presentations should be continued on cabergoline with the addition of clozapine as it has less of an effect on PRL levels. Other treatment options also include aripiprazole and quetiapine. However, when patients have treatment resistant macroprolactinomas and are unable to tolerate cabergoline, one would have to consider surgical treatment options for the treatment of hyperprolactinemia from pituitary macroadenomas. Presentation: 6/1/2024