What is Cabergoline?
Cabergoline is a long-acting dopamine agonist medication with high specificity and affinity for dopamine D2 receptors, primarily used to treat hyperprolactinemia by suppressing prolactin secretion. 1, 2, 3
Mechanism and Clinical Use
- Cabergoline is a synthetic ergoline derivative that acts as a potent dopamine receptor agonist, specifically targeting D2 receptors to inhibit prolactin secretion from the pituitary gland 3, 4
- The medication is FDA-approved for treating hyperprolactinemic disorders, including prolactinomas (both micro- and macroadenomas) and idiopathic hyperprolactinemia 1, 5
- Standard initial dosing is 0.25 mg twice weekly, with gradual increases up to 2 mg/week for most patients 1, 2
Clinical Efficacy
- Cabergoline is superior to bromocriptine, normalizing prolactin levels in 83% versus 59% of patients, and has a significantly better side effect profile (52% versus 72% adverse events) 1, 6
- The medication normalizes prolactin levels in 86% of all hyperprolactinemic patients: 92% with microprolactinomas or idiopathic disease, and 77% with macroadenomas 5
- Tumor shrinkage occurs in 67-80% of cases, visual field abnormalities normalize in 70% of affected patients, and ovulatory cycles are restored in 72% of women 1, 5, 6
Side Effects
Common Adverse Effects
The most frequent side effects are gastrointestinal and neurological symptoms, occurring in approximately 50-68% of patients, though most are mild and transient: 7, 6
- Nausea (most common gastrointestinal complaint) 7, 8
- Headache 7, 8
- Dizziness and orthostatic hypotension (particularly with initial doses higher than 1.0 mg) 3, 7, 8
- Fatigue and weakness 7, 8
- Constipation and gastric pain 7, 8
Serious Adverse Effects
Cardiac Complications
- For patients on doses >2 mg/week, annual echocardiography with cardiac auscultation is mandatory due to risk of cardiac valvulopathy 1, 2
- For patients on ≤2 mg/week, echocardiographic surveillance can be reduced to every 5 years 1, 2
- Higher doses used for Parkinson's disease (up to 21 mg/week) significantly increase the risk of cardiac valvulopathy 1
Psychiatric and Behavioral Side Effects
Impulse control disorders and compulsive behaviors are dose-independent dopaminergic effects that require immediate attention: 1, 3
- Pathological gambling, uncontrollable spending urges, hypersexuality, and increased libido have been reported 3
- Mood changes, depression, and aggression may occur, particularly in children and adolescents 1
- These effects are generally reversible upon dose reduction or treatment discontinuation 3
- Prescribers must consider dose reduction or stopping medication if these urges develop 3
Other Serious Complications
- Cerebrospinal fluid rhinorrhea can occur when medication-induced tumor shrinkage affects prolactinomas that have invaded the sphenoid bone 1
- Postpartum use requires caution, though cabergoline has not been associated with the thromboembolic events reported with bromocriptine 4
Tolerability and Discontinuation
- Only 3-4% of patients discontinue cabergoline due to side effects, compared to 12% with bromocriptine 5, 6
- Over 95% of reported symptoms are relatively trivial and transient 7
- Small nocturnal dose increments can reduce gastrointestinal intolerance and postural hypotension 1
- Most patients intolerant of other ergot derivatives can tolerate cabergoline 4
Important Precautions
- Cabergoline should not be administered concurrently with D2-antagonists (phenothiazines, butyrophenones, thioxanthenes, or metoclopramide) 3
- Caution is required in patients with hepatic impairment since the drug is extensively metabolized by the liver 3
- Patients should notify their physician if they suspect pregnancy, as continuation of treatment should be discussed 3
- Patients should report shortness of breath, persistent cough, difficulty breathing when lying down, or extremity swelling 3