Impulse Control Disorders with Short-term Use of Cabergoline in Macroprolactinomas: A Prospective Study with a Brief Review of Literature

Impulse control disorders (ICDs) are less-emphasized adverse effects of dopamine agonists. Evidence on prevalence and predictors of ICDs in patients with prolactinomas is limited and confined chiefly to cross-sectional studies. This was a prospective study performed to investigate ICDs in treatment-naïve patients with macroprolactinomas (n = 15) using cabergoline (Group I), compared to consecutive patients of nonfunctioning pituitary macroadenomas (n = 15) (Group II). Clinical, biochemical, radiological parameters and psychiatric comorbidities were evaluated at baseline. ICD was assessed by Minnesota impulsive disorder interview, modified hypersexuality and punding questionnaires, South Oaks gambling scale, kleptomania symptom assessment scale, Barratt impulsive scale (BIS), and internet addiction scores (IAS) at baseline and 12 weeks. Group I had a significantly lower mean age (28.5 vs. 42.2 years) with a female predominance (60%) compared to group II. Median tumor volume was lower in group I (4.92 vs. 14 cm³) despite significantly longer symptom duration (2.13 vs. 0.80 years) than in group II. Serum prolactin decreased by 86% (P = 0.006) and tumor volume decreased by 56% (P = 0.004) at 12 weeks in group I, with a mean weekly cabergoline dose of 0.40 ± 0.13 mg. There was no difference between both groups in hypersexuality, gambling, punding, and kleptomania symptom assessment scale scores at baseline and 12 weeks. Mean BIS showed a more remarkable change in group I (16.2% vs. 8.4%, P = 0.051), and 38.5% of patients transitioned from average to above-average IAS in group I. The current study found no increased risk of ICD with short-term use of cabergoline in patients with macroprolactinomas. The use of age-appropriate scores (such as IAS in younger individuals) may help diagnose subtle alterations in impulsivity.