Ergoline

The ergoline dopamine agonists should only be used in exceptional circumstances and after the non-ergoline agonist have been tried.

Fibrotic reactions: Ergot-derived dopamine-receptor agonists, bromocriptine, cabergoline, and pergolide, have been associated with pulmonary, retroperitoneal, and pericardial fibrotic reactions.

Exclude cardiac valvulopathy with echocardiography before starting treatment with these ergot derivatives for Parkinson's disease or chronic endocrine disorders (excludes suppression of lactation); it may also be appropriate to measure the erythrocyte sedimentation rate and serum creatinine and to obtain a chest X-ray. Patients should be monitored for dyspnoea, persistent cough, chest pain, cardiac failure, and abdominal pain or tenderness. If long-term treatment is expected, then lung-function tests may also be helpful. Patients taking cabergoline or pergolide should be regularly monitored for cardiac fibrosis by echocardiography (within 3–6 months of initiating treatment and subsequently at 6–12 month intervals).

Ergot derivatives (bromocriptine, cabergoline and pergolide) act by direct stimulation of surviving dopamine receptors. Although effective, they have no advantages over levodopa. They should be reserved for patients in whom levodopa alone is no longer adequate or who, despite careful titration, cannot tolerate levodopa. They are sometimes useful in reducing "off" periods in ameliorating fluctuations in the later stage of Parkinson's disease.

Excessive daytime sleepiness and sudden onset of sleep can occur with dopaminergic drugs. Patients starting treatment with these drugs should be warned of the possibility of these effects and of the need to exercise caution when driving or operating machinery.

Bromocriptine

• Tablets 2.5mg (£65.67 = 30 tablets)

Indications

• Prevention or suppression of lactation
• Parkinson's disease

Dose

• Prevention or suppression of lactation, 2.5mg on day 1 (prevention) or daily for 2–3 days (suppression); then 2.5mg twice daily for 14 days
• Parkinson's disease, first week 1–1.25mg at night, second week 2–2.5mg at night, third week 2.5mg twice daily, fourth week 2.5mg 3 times daily then increasing by 2.5mg every 3–14 days according to response to a usual range of 10–30mg daily
• Hypogonadism, galactorrhoea, infertility, initially 1–1.25mg at bedtime, increased gradually; usual dose 7.5mg daily in divided doses, increased if necessary to max. 30mg daily, usual dose in infertility without hyperprolactinaemia, 2.5mg twice daily
• Acromegaly, initially 1–1.25mg at bedtime, increase gradually to 5mg every 6 hours
• Prolactinoma, initially 1–1.25mg at bedtime; increased gradually to 5mg every 6 hours (occasional patients may require up to 30mg daily)

Notes

1. Bromocriptine has a known safety profile in pregnancy; further data is required to warrant prescribing cabergoline under such circumstances.

Cabergoline

• Tablets 500micrograms, 1mg, 2mg (£84.00 = 20 x 2mg tablets)

Indications

• Alone or as adjunct to co-beneldopa or co-careldopa in Parkinson's disease where dopamine-receptor agonists other than ergot derivative not appropriate
• Endocrine disorders

Dose

• Prevention of lactation, during first day postpartum, 1mg as a single dose; suppression of established lactation 250micrograms every 12 hours for 2 days
• Parkinson's disease, initially 1mg daily, increased by increments of 0.5–1mg at 7 or 14 day intervals; maximum 3mg daily
• Hyperprolactinaemic disorders, 500micrograms weekly (as a single dose or as 2 divided doses on separate days) increased at monthly intervals in steps of 500micrograms until optimal therapeutic response (usually 1mg weekly, range 0.25–2mg weekly) with monthly monitoring of serum prolactin levels; reduce initial dose and increase more gradually if patient intolerant; over 1mg weekly give as divided doses; up to 4.5mg weekly has been used in hyperprolactinaemic patients

Notes

1. Cabergoline has an advantage of administration on a once weekly basis although it is more expensive than bromocriptine. Evidence suggests it is better tolerated.
2. Please remember to optimize patient's prescription as their doses change; two 1mg tablets are considerably more costly than one 2mg tablet.