Poster Presentation ESA-SRB-ANZBMS 2024 in conjunction with ENSA

Low-dose clonazepam can ameliorate severe psychological side effects of dopamine agonists in invasive prolactin-secreting pitNETs (#597)

William Kovacevic 1 , Rebecca Teng Jing Yap 1 , Emily Hibbert 1 2 3
  1. Nepean Hospital, Penrith, NSW
  2. Charles Perkins Centre - Nepean, Faculty of Medicine and Health, University of Sydney, NSW
  3. Nepean Clinical School, Faculty of Medicine and Health, University of Sydney, NSW

Background: Dopamine agonists are first-line treatment for prolactin secreting neuro-endocrine tumours (pitNETs) but can be associated with psychiatric side effects, particularly impulse control disorders1. These side effects can necessitate dose reduction or cessation and early surgical intervention2.

Case study: A 52-year-old gentleman underwent brain imaging after experiencing recurrent dizziness for over two years. MRI demonstrated an invasive 18x31x22mm lobulated pituitary mass with optic chiasm compression and extrasellar extension, not involving the cavernous sinus. He had mild superior field defects on perimetry. Biochemistry confirmed a prolactin-secreting pitNET with serum prolactin 22,460mIU/L (reference range 0-500mIU/L), with hypogonadotropic hypogonadism but no other pituitary dysfunction. He was started on cabergoline 0.5mg twice weekly, reducing prolactin levels and tumour size on MRI. However, he experienced significant psychiatric adverse effects including thoughts of self-harm, alcohol, gambling, and reckless driving which resulted in a motor vehicle accident and almost cost him his marriage. Consequently, he stopped cabergoline. He was lost to follow-up for 2 years, moved interstate and was referred to a new endocrinologist. Repeat MRI showed optic chiasm indentation and new right cavernous sinus extension with partial right carotid artery encasement. Following psychiatrist assessment, he was started on low-dose clonazepam in conjunction with cabergoline 0.5mg weekly. Clonazepam significantly reduced, but did not completely prevent side effects. This prompted referral for endoscopic transsphenoidal resection of the pituitary lesion 5 months after cabergoline recommencement. Surgery resulted in panhypopituitarism, but complete resolution of psychiatric side effects. At 1 month post-operatively, prolactin was normal and MRI scan showed full clearance of the pitNET, including from the right cavernous sinus.

Discussion: In people with severe psychiatric side effects of dopamine agonists in prolactin secreting pitNETs, low dose clonazepam can ameliorate these side effects, facilitating its use as a temporising measure prior to early pitNETs resection.

 

  1. De Sousa et al. Impulse Control Disorders in Dopamine Agonist-Treated Hyperprolactinemia: Prevalence and Risk Factors. The Journal of Clinical Endocrinology & Metabolism, Volume 105, Issue 3, March 2020, Pages e108–e118
  2. Petersenn, S., Fleseriu, M., Casanueva, F.F. et al. Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement. Nat Rev Endocrinol 19, 722–740 (2023)