BROMOCRIPTINE MESYLATE
Clinical safety rating
safeAnimal studies have demonstrated safety
Bromocriptine mesylate is a dopamine D2 receptor agonist that also exhibits partial agonist activity at D1 receptors. By stimulating dopamine receptors in the tuberoinfundibular pathway, it inhibits prolactin secretion from the anterior pituitary. It also activates postsynaptic dopamine receptors in the striatum, improving motor function in Parkinson disease. Additionally, it has been shown to improve glycemic control in type 2 diabetes by modulating central dopaminergic tone and reducing hepatic glucose production.
| Metabolism | Extensively metabolized primarily by cytochrome P450 3A4 (CYP3A4) to multiple metabolites, including the major active metabolite 2-bromo-α-ergocriptine. Also undergoes non-CYP-mediated hydrolysis and conjugation. First-pass metabolism is significant, resulting in ~6% oral bioavailability. |
| Excretion | Primarily hepatic metabolism with 85-90% fecal excretion via bile; <5% renal excretion as unchanged drug and metabolites. |
| Half-life | Terminal elimination half-life is approximately 6-8 hours in healthy individuals, but may be prolonged to 12-14 hours in patients with hepatic impairment or in the elderly. |
| Protein binding | 90-96% bound to serum albumin, with some binding to alpha-1-acid glycoprotein. |
| Volume of Distribution | Approximately 2-3 L/kg, indicating extensive tissue distribution and penetration into breast milk and central nervous system. |
| Bioavailability | Oral: 28-30% due to extensive first-pass metabolism; sublingual: 40-50% due to partial avoidance of hepatic first-pass; rectal: approximately 20%. |
| Onset of Action | Oral: 1-2 hours for prolactin-lowering effect; inhibition of prolactin secretion begins within 2 hours. For Parkinson's disease, clinical response may take 2-4 weeks. Sublingual administration may have slightly faster onset. |
| Duration of Action | Prolactin suppression: 8-12 hours; clinical effects for Parkinson's disease may persist for 4-8 hours after a single dose. Sustained use required for continuous effect. |
| Molecular Weight | 750.7 Da (bromocriptine mesylate) |
Oral: 1.25-2.5 mg twice daily, increased gradually as tolerated. Maximum 100 mg/day. Also used intravaginally for hyperprolactinemia (2.5 mg once daily).
| Dosage form | CAPSULE |
| Renal impairment | No specific dose adjustment recommended; monitor for accumulation in severe renal impairment (eGFR <30 mL/min). |
| Liver impairment | Child-Pugh A: No adjustment; Child-Pugh B: Reduce dose by 50%; Child-Pugh C: Avoid use. |
| Pediatric use | Prolactinomas: 1.25-2.5 mg/m²/day orally in 2-3 divided doses; titrate based on response. Weight-based: 0.01-0.02 mg/kg/day, increase slowly. |
| Geriatric use | Initiate at low end of dosing range (1.25 mg once or twice daily) due to increased sensitivity and risk of hypotension; titrate slowly. |
| 1st trimester | Avoid due to potential for miscarriage or neural tube defects; embryotoxic in animal studies. |
| 2nd trimester | Use only if clearly needed; monitor for gestational hypertension and placental abruption risk. |
| 3rd trimester | Use only if clearly needed; may suppress postpartum lactation and cause maternal hypertension. |
Clinical note
Other drugs that lower blood pressure may have additive effects Ergot-related drugs may cause fibrosis of cardiac valves with long-term use.
| Placental transfer | Bromocriptine crosses the placenta; demonstrated in animal studies; human data limited but expected. |
| Breastfeeding | Bromocriptine suppresses lactation and is contraindicated in breastfeeding women due to reduction in milk production and potential for adverse effects in the infant. |
| Lactation Rating | L5 (Contraindicated) |
| Teratogenic Risk | First trimester: Limited human data; animal studies show increased fetal resorption and growth retardation at high doses. Second and third trimesters: Risk of postpartum hemorrhage due to uterine atony; may suppress pituitary prolactin, potentially impairing placental lactogen production. Overall, use only if clearly needed. |
| Fetal Monitoring | Monitor blood pressure (risk of hypertension or hypotension, including postpartum cerebrovascular accidents), uterine tone (risk of atony and hemorrhage), and signs of stroke or seizure. Periodic assessment of renal and liver function recommended. |
| Fertility Effects | Bromocriptine is used to treat hyperprolactinemia-induced infertility by restoring ovulatory cycles. In normoprolactinemic women, it may have no effect or potentially impair fertility due to prolactin suppression. Use in pregnancy should be discontinued once conception is confirmed unless treating prolactinoma. |
■ FDA Black Box Warning
None
| Common Effects | hyperprolactinemia |
| Serious Effects |
Uncontrolled hypertensionPreeclampsiaEclampsiaSevere coronary artery diseasePeripheral vascular diseaseLactation (postpartum)
| Precautions | May cause hypotension (especially postural), syncope, and severe adverse reactions such as myocardial infarction, stroke, seizures, and psychosis. Can cause pleural and retroperitoneal fibrosis, pericarditis, and valvulopathy (especially with high doses for Parkinson disease). Has been associated with pathological gambling, hypersexuality, and impulse control disorders. May cause somnolence and sudden sleep onset. Monitor for cardiac valvulopathy and pulmonary fibrosis. Use with caution in patients with cardiovascular disease, peptic ulcer disease, or a history of mental illness. |
| Food/Dietary | Take with food to reduce gastrointestinal irritation; avoid high-protein meals if using for hyperprolactinemia as protein may decrease absorption. |
| Clinical Pearls | Titrate slowly to minimize orthostatic hypotension and gastrointestinal upset. Administer with food to reduce nausea. Monitor for pulmonary fibrosis and Raynaud phenomenon with long-term use. Avoid concomitant use with ergot alkaloids due to additive vasospasm risk. |
| Patient Advice | Take with food to reduce nausea and lightheadedness. · Rise slowly from sitting or lying to prevent dizziness from low blood pressure. · Avoid alcohol as it may worsen side effects. · Report persistent cough, chest pain, or changes in urination or vision. · Do not stop abruptly; taper under medical supervision. |
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