Bromocriptine

Though kava should no longer be available in Canada, it should be noted that kava may antagonize the dopaminergic effects of bromocriptine; concomitant administration should be avoided.

Concomitant therapy with other ergot alkaloids (e.g., cabergoline, ergotamine derivatives, ergonovine, methysergide) should be avoided due to the theoretical risk of additive vasoconstrictive effects.

Although no specific guidelines are established, dosage adjustment may be necessary in patients with significant hepatic impairment as the drug is almost completely metabolized in the liver.

Dosage adjustment is not routinely recommended in patients with renal impairment.

Rarely, cerebrospinal fluid rhinorrhea has occurred in patients taking bromocriptine for the treatment of large prolactinomas.

Seizures and stroke have occurred rarely in women who took bromocriptine postpartum to suppress lactation; bromocriptine is no longer recommended for this indication.

Exacerbation or precipitation of manic episodes, hallucinations and other psychotic symptoms have occurred in patients taking bromocriptine. Concomitant therapy with levodopa may increase the risk of these effects.

Pleuropulmonary changes including pleural effusion, pleural thickening and pulmonary infiltrates have occurred rarely. Previous asbestos exposure may be a predisposing factor. Patients taking bromocriptine who experience unexplained pleuropulmonary symptoms should be investigated thoroughly to rule out serious lung changes necessitating immediate withdrawal of the drug. Retroperitoneal fibrosis has also occurred rarely. Pleuropulmonary changes and retroperitoneal fibrosis are usually associated with long-term use and may be dose-related.

Bromocriptine has been associated with cold-induced vasoconstriction in the fingers. This usually responds to dosage reduction and can also be avoided by keeping the fingers warm.

While hypotension occurs more frequently especially during initial therapy (see Table 1), hypertension has also been reported, rarely.

Although bromocriptine is not renally eliminated, caution is advised in patients with renal failure as there is little experience with its use in this population. Dosage adjustment is not routinely recommended based on renal function.

Bromocriptine is metabolized in the liver. Although no specific guidelines are available, caution is advised in patients with significant hepatic impairment, and dosage adjustment may be indicated.

Based on older case reports of peptic ulceration and bleeding in patients taking bromocriptine for acromegaly, it is recommended that bromocriptine be used with caution or alternate therapy be considered in patients with a history of peptic ulcer disease.

Bromocriptine therapy can be continued in the perioperative period when appropriate.

To assess effectiveness of therapy, serum prolactin is measured in patients treated for hyperprolactinemia; for acromegaly, growth hormone levels are monitored. To monitor for adverse effects, blood pressure should be periodically measured, and visual field examinations are performed in patients with macroprolactinomas.

Patients should be warned that bromocriptine-induced somnolence or sudden onset of sleep can impair their ability to perform hazardous tasks such as operating machinery or driving a motor vehicle.

During treatment of macroprolactinoma, visual field examinations are recommended to monitor effects on the optic chiasm caused by changes in the dimensions of the prolactinoma. Rapid visual field loss requires evaluation by a neurosurgeon.

See Boxed Serious Warnings and Precautions.

Bromocriptine is sometimes used in children ≥11 years in the management of hyperprolactinemic conditions. The usual adult precautions apply when bromocriptine is used in this setting.

Bromocriptine has not been associated with an increased risk of congenital birth defects and is sometimes used during pregnancy to suppress the growth of macroprolactinomas. Visual field examinations are indicated during pregnancy to monitor effects of changing tumor size on the optic chiasm.

Women who receive bromocriptine during the postpartum period should be closely monitored for cardiovascular effects such as hypotension or hypertension. It is because of serious cardiovascular effects and seizures in the postpartum population that bromocriptine is no longer indicated for suppression of lactation following childbirth.

Women being treated for galactorrhea and/or prolactin-induced amenorrhea need to be aware that fertility may be restored during bromocriptine therapy. Women who are sexually active during this treatment period are advised to use a barrier (nonhormonal) contraceptive method until such time as fertility is established and pregnancy is desired.

Because it suppresses lactation, bromocriptine is not compatible with breastfeeding.

Dose-related hypotension, including first-dose syncope, postural hypotension and severe prolonged hypotension, can occur in patients taking bromocriptine. Blood pressure should be monitored periodically, especially when therapy is initiated and in patients taking other hypotensive drugs.

Rarely, hypertension has also occurred.

Because psychotic symptoms such as hallucinations have occurred in association with bromocriptine therapy, the drug should be used cautiously in patients with a history of psychotic disorders.

Bromocriptine is well absorbed following oral administration, and is subject to a high hepatic extraction ratio and first-pass metabolism which results in approximately 6-7% of the original dose reaching the systemic circulation unchanged. Peak plasma concentrations are reached in 1 to 1.5 hours.

Bromocriptine is approximately 90-96% bound to serum albumin. As a substrate of CYP3A4, bromocriptine is almost completely metabolized in the liver to inactive metabolites that are subsequently eliminated through biliary excretion in the feces. The elimination half-life of bromocriptine is approximately 2-8 h.