dopamine receptor agonists - PD Flashcards
name the 4 non ergot derived DRA
pramipexole
rotigotine
ropinirole
apomorphine
3 out of 4 non-ergot derived DRAs can be used for restless legs. which ones
pramipexole
rotigotine
ropinirole
dopamine receptor agonists are associated with impulse control disorders e.g. pathological gambling, binge eating, hyper sexuality. will switching between different DRA (i.e. ergot and non ergot) control these SE?
No, ergot and non-ergot derived DRA do not differ in their likelihood to cause impulse control disorders
amantadine - drug action
weak dopamine agonist with modest antiparkinsonian effects
when is amantadine indicated in PD
if pt develops dyskinesia and it is not adequately managed by modifying existing therapy, consider amantadine
amantadine - 2 contraindications
epilepsy
Hx gastric ulcer
this drug is used for PD, and is also licensed for prophylaxis and treatment of influenza A (but not recommended)
amantadine
when is apomorphine indicated in PD
severe PD - refractory motor fluctuations in PD (‘off’ episodes) that are inadequately controlled by co-beneldepa or co-careldopa or other dopaminergic, under expert supervision
Apomorphine is given with this antiemetic to reduce risk of nausea and vomiting, however there is an interaction between them both
domperidone
both increase risk of QT interval prolongation so it is advised they are actually avoided
name the 3 ergot derived DRA
- bromocriptine
- cabergoline
- quinagolide
drug action of bromocriptine
stimulant of dopamine receptors in brain
also inhibits release of prolactin by pituitary
which 2 ergot derived DRA are licensed for suppression of lactation (although not recommended for routine suppression, or for the relief of symptoms of PP pain and engorgement) that can be adequately treated with simple analgesics and breast support
bromocriptine
cabergoline (preferred)
important safety info bromocriptine - fibrotic and serosal reactions
- esp with long term and high dose treatment
- associated with pulmonary, pleural, retroperitoneal and pericardial fibrosis (latter often manifests as cardiac failure), pleural and pericardial effusions, and constrictive pericarditis
- baseline investigations and regular monitoring for signs and symptoms of these reactions should be undertaken and treatment stopped if suspected
important safety info for bromocriptine - impulse control disorders
DRA associated with impulse control disorders
inform pt and carer of the risk
ergot and non-ergot do not differ in their propensity to cause impulse control disorders
bromocriptine important safety info - prevention or suppression of lactation
only use where medically indicated! e..g intrapartum loss, neonatal death, mother with HIV infection
do not use for routine suppression of lactation or to relieve symptoms of PP breast pain and engorgement
monitor BP carefully esp during first days of treatment
bromocriptine is contraindicated in…
uncontrolled hypertension
hypertensive disorders of pregnancy (e.g. pre-eclampsia, eclampsia, pregnancy induced hypertension)
hypertension in PP women or in puerperium
cardiac valvulopathy (exclude before long term treatment)
discontinue bromocriptine immediately if …
hypertension, suggestive chest pain, severe progressive or unremitting headache (sign of stroke), or signs of CNS toxicity
what to do if GI bleeding occurs with bromocriptine
withdraw
DRA - sudden onset of sleep
- excessive daytime sleepiness and sudden onset of sleep can occur with DRA
- warn pt of risk and the need to exercise caution when driving or operating machinery
- if excessive sedation or sudden onset of sleep, refrain from driving or operating machinery until effect stopped
DRA - hypotensive reactions
- can occur in some pt taking DRA
- can be particularly problematic during first few days of treatment
- exercise care when driving or operating machinery
bromocriptine monitoring
- BP few days after starting and following dose increase
- baseline chest X rays/lung function tests, serum creatinine, inflammatory markers before starting treatment
- monitor for fibrotic or serosal inflammatory changes during treatment
bromocriptine - fibrotic or serosal inflammatory changes during treatment manifest as
dyspnoea, persistent cough, chest pain, cardiac failure, back pain, lower limb oedema, or renal impairment. discontinue if suspected.
cabergoline drug action
stimulant of dopamine receptors in the brain and it also inhibits release of prolactin by the pituitary.
cabergoline - fibrotic reactions, safety info
- risk of pulmonary, retroperitoneal, pericardial fibrotic reactions
- exclude cardiac valvulopathy with ECG before treatment for ergot derivatives for PD or chronic endocrine disorders
- may also be appropriate to measure ESR and creatinine and obtain chest X ray
monitor pt for dyspnoea, persistent cough, chest pain, cardiac failure, abdominal pain or tenderness - LFTs may be helpful if long term treatment needed
- regularly mounter for cardiac fibrosis by ECG (within 3-6m of initiation, subsequently at 6-12m intervals)
