Endocrine Abstracts

Background: Dopamine agonists (DA) remain the first-line medical therapy for prolactinomas and idiopathic hyperprolactinemia in Endocrinology. DA can also be efficacious in a selected group of patients with acromegaly. There is increasing awareness, among endocrinologists, of Impulse Control Disorders (ICDs) as possible adverse effects of DA therapy.

Case reports: We describe ICDs in four patients (two diagnosed with prolactinoma and two diagnosed with acromegaly) treated with low-dose DA. Our patients, aged 37 to 67 years, developed a range of ICDs including hypersexuality, excessive spending, punding (repetitive performance of tasks) and obsessive thoughts with insight. Two patients reported a breakdown of established relationships or multiple failed relationships due to hypersexuality.

Discussion: ICDs are well-recognised side effects in patients with Parkinson’s disease (PD) treated with higher doses of DA compared to the doses used in endocrine conditions. Emerging evidence of ICDs due to DA in Endocrinology is relatively recent, mostly documented in case reports. Other ICDs reported in the PD literature include pathologic gambling, compulsive eating and dopamine dysregulation syndrome (compulsion to seek and overuse DA). The development of ICDs can have serious consequences on patients and their families. Endocrinologists involved in the care of patients on DA therapy must be aware of this potentially devastating adverse effect and offer regular counselling regarding pertinent symptoms at initiation and during long-term follow-up, to enable early detection of ICDs. In patients who develop ICDs on DA therapy, cessation or tapering down of DA have been reported as successful management options, especially in the wider PD population. However, in Endocrinology, there are currently no published treatment guidelines for DA-induced ICDs. Due consideration should be given within a multidisciplinary approach to surgical, hormonal and non-pharmacologic (psychotherapy and cognitive behavioural therapy) treatment, depending on the initial endocrine diagnosis.