DOSTINEX

Indications

• Hyperprolactinemia
• Prolactin-secreting pituitary adenomas
• Acromegaly (in some cases as part of treatment regimen)

Dosage

Children: Refer to the BNF for Children for pediatric dosing information.

Adults: Refer to the BNF for specific dosing guidelines.

Mechanism of action

Carbegoline acts as a selective agonist for dopamine D2 receptors. By binding to these receptors, it mimics the action of dopamine, inhibiting the secretion of prolactin from pituitary lactotrophs. This reduction in prolactin levels is beneficial in managing conditions associated with hyperprolactinemia.

Pharmacodynamics

The pharmacodynamic effects of carbegoline primarily involve the suppression of prolactin release. It also has a longer half-life compared to other dopamine agonists, allowing for less frequent dosing. Its effects on dopamine receptors can influence other hormonal axes and may have implications for mood and motility.

Pharmacokinetics

Carbegoline is well absorbed after oral administration, with peak plasma concentrations occurring approximately 1 to 4 hours post-dose. It has a long elimination half-life of approximately 63 to 109 hours, allowing for once or twice weekly dosing. The drug is metabolized in the liver, primarily via cytochrome P450 enzymes, and its metabolites are excreted mainly in the feces.

Contra-indications

• Hypersensitivity to carbegoline or any component of the formulation
• History of cardiac valvulopathy
• Severe hepatic impairment

Adverse effects

• Nausea
• Headache
• Dizziness
• Fatigue
• Hypotension
• Constipation
• Abdominal pain
• Peripheral edema

Interactions

• Dopamine agonists may have additive effects when used with other medications that lower blood pressure
• Avoid use with strong CYP3A4 inhibitors which may increase carbegoline levels
• Caution is advised when used with other drugs that affect the dopaminergic system

Precautions

• Monitor for signs of cardiac valvulopathy, especially in long-term use
• Use with caution in patients with a history of psychiatric disorders
• Regular monitoring of blood pressure is recommended
• Assess renal function before initiation and during treatment

Pregnancy

Carbegoline is not recommended during pregnancy due to potential risks to the fetus. Use in pregnancy only if the benefits outweigh the risks.

Breast-feeding

Carbegoline is excreted in breast milk. Caution is advised, and breastfeeding should be monitored or discontinued during treatment.

Storage

Store at room temperature, away from moisture and heat. Protect from light.

Formulations

• Tablets: 0.5 mg, 1 mg