Dopamine Receptor Agonists Flashcards
What effect does dopamine have on the anterior pituitary?
Inhibits release of prolactin
Thus, dopamine agonists can be used in the treatment of galactorrhea and prolactinomas
What are the three main drugs in the family of dopamine agonists?
- Bromocriptine
- Cabergoline
- Quinagolide
What are the actions of bromocriptine? (2)
- Inhibits PRL release
2. Also inhibits release of GH (sometimes used in the treatment of acromegaly, but somatostatin analogues are preferred)
Do dopamine agonists have a role in lactation suppression?
Yes, but they should NOT be used for routine suppression or relief of symptoms of postpartum pain and engorgements that can be adequately treated with simple analgesia and breast support
Which dopamine agonist is preferred for lactation suppression?
Cabergoline is first line
Bromocriptine can also be used
Quinagolide is NOT licensed for suppression of lactation
What are the indications of bromocriptine? (8)
- Prevention of lactation
- Suppression of lactation
- Hypogonadism
- Galactorrhea
- Infertility
- Acromegaly
- Prolactinoma
- Parkinson’s disease
What are the important safety considerations that should be taken when prescribing bromocriptine and cabergoline? (2)
- Fibrotic reactions (pulmonary, retroperitoneal, and pericardial); exclude cardiac valvulopathy with echo before starting treatment +/- measure ESR and serum Cr +/- CXR and LFTs
- Impulse control disorders eg pathological gambling, binge eating, hypersexuality
“Ergot-derived dopamine agonists” include which drugs? (5)
- Bromocriptine
- Cabergoline
- Dihydroergocryptine
- Lisuride
- Pergolide
What are the contraindications to the use of bromocriptine and cabergoline?
- Cardiac valvulopathy (exclude before treatment due to risk of fibrotic disease)
- HTN in postpartum women or in puerperium
- Hypertensive disorders of pregnancy (pre-eclampsia, eclampsia, pregnancy-induced HTN)
What precautions should be taken when stopping treatment with ergot-derived dopamine agonists?
Antiparkinsonian drug therapy should never be stopped abruptly as this carries a small risk of neuroleptic malignant syndrome
What additional information should be given to patients taking bromocriptine, cabergoline, and quinagolide? (3)
- Excessive daytime sleepiness and sudden onset of sleep can occur with dopamine-receptor agonists
- Patients starting treatment with these drugs should be warned of the risk and of the need to exercise caution when driving or operating machinery. Those who have experienced excessive sedation or sudden onset of sleep should refrain from driving or operating machines until these effects have stopped occurring.
- Hypotensive reactions can occur in some patients taking dopamine-receptor agonists; these can be particularly problematic during the first few days of treatment and care should be exercised when driving or operating machinery.
What are the indications for Cabergoline? (4)
- Prevention of lactation
- Suppression of established lactation
- Hyperprolactinemic disorders
- Alone or as an adjunct to co-beneldopa or co-careldopa in PD where dopamine-receptor agonists other than ergot derivatives not appropriate
What precautions should be taken when prescribing cabergoline in women of childbearing potential? (5)
- Exclude pregnancy before starting
- Perform monthly pregnancy tests during the amenorrheic period
- Advise non-hormonal contraception if pregnancy not desired
- Discontinue 1 month before intended conception
- Discontinue if pregnancy occurs during treatment
What is the main indication for quinagolide?
Hyperprolactinemia
What class of drug is quinagolide?
Non-ergot dopamine agonist
