Bromocriptine
Bromocriptine suppresses prolactin and has reproductive uses in dogs. It has not been effective for canine pituitary-dependent hyperadrenocorticism.
Group
Dopamine agonist and prolactin inhibitor
Mechanism of Action
Activates dopamine D2 receptors and suppresses anterior pituitary prolactin release.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Pregnancy termination | Reference only | PO | Use the staged bromocriptine–cloprostenol course described under Monitoring and Administration; this is a combination protocol. | |
| Lactation suppression | Reference only | PO | 10–100 mcg/kg every 12 hours for 10–14 days. The dosage bullet does not explicitly identify the administration route. | |
| Pseudopregnancy | 10–30 mcg/kg | PO | Every 12 h | If adverse effects occur, reduction to 7.5 mcg/kg is described. |
| Other endocrine conditions | 20–40 mcg/kg | PO | Every 12 h | The source does not identify a specific endocrine diagnosis for this general regimen. |
| Lactation suppression | 10–100 mcg/kg | PO | Every 12 h | Up to 14 days; Course 10–14 days; food and dose reduction may reduce vomiting. |
| Pseudopregnancy | 10–50 mcg/kg | PO | Every 12 h | An alternative described at least twice daily; adjust to prolactin signs and tolerance. |
| Pregnancy termination | 50–100 mcg/kg | PO, IM | Every 12 h | Up to 7 days; Start 35–45 days after the LH surge; course 4–7 days. Not uniformly effective; vomiting is common. Injectable use requires an appropriate sterile preparation. |
| Pregnancy termination with cloprostenol | Reference only | PO | From approximately 25 days after the LH surge: bromocriptine 30 mcg/kg orally every 24 hours plus cloprostenol 1 mcg/kg SC every 48 hours; this differs from the staged bromocriptine course already listed. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Other endocrine conditions | 20–40 mcg/kg | PO | Every 12 h | The source does not identify a specific endocrine diagnosis for this general regimen. |
| Acromegaly adjunct | Reference only | PO | An initial total dose of 0.2 mg is described, but route and repeat schedule are not assigned; insulin needs may change. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Pituitary dysfunction | 30–90 mcg/kg | PO, SC | Every 12 h | Limited-use historical alternative; pergolide is generally preferred. |
| Pituitary dysfunction | 5 mg/animal | IM | Every 12 h | Requires an appropriate sterile injectable formulation; do not inject an unvalidated oral-tablet mixture. |
Indications
- Pseudopregnancy
- Lactation suppression
- Pregnancy termination in combination with prostaglandin
Contraindications
- Pregnancy except intended termination.
- Lactation when continued nursing is desired.
- Hypertension; use cautiously with hepatic impairment.
Interactions
- Do not combine with MAO inhibitors, including selegiline.
- Cyclosporine concentrations may increase; dopamine antagonists can reduce efficacy.
- Erythromycin, clarithromycin and octreotide may raise bromocriptine exposure.
- Other hypotensive agents can worsen hypotension; other ergot drugs or sympathomimetics can produce serious cardiovascular interactions.
- Estrogens or progestins can oppose the desired endocrine effect; metoclopramide can increase prolactin release.
Adverse effects
- Vomiting, nausea and retching
- Hypotension
- Mammary changes
- Pyometra after pregnancy termination
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Bromocriptine 2.5 mg tablet | Tablet | 2.5 mg / tablet | PO |
| Bromocriptine 5 mg capsule | Capsule | 5 mg / capsule | PO |
Monitoring and Administration
Confirm complete pregnancy termination and monitor uterine discharge.
For pregnancy termination, give orally 15 mcg/kg every 12 hours on day 1, 20 mcg/kg every 12 hours on days 2–3, then 30 mcg/kg every 12 hours. Treatment averages 4–5 days but may require 10 days. Combine with cloprostenol 1 mcg/kg subcutaneously every 48 hours.
A 2.5 mg tablet dissolved to a final 10 mL gives 250 mcg/mL. Refrigerate in amber glass and use within one week. Avoid exposure during handling, particularly for women who may be pregnant.