DA receptor agonist Flashcards
Where receptors D1-D5 found?
cerebral cortex and limbic system
Where are D3 + D5 receptors found?
Hypothalamus
Where are D1 + D2 receptors found?
Corpus striatum
What D1 receptor agonist stimulate?
STIMULATE Adenylate cyclase to ACTIVATE the DIRECT PATHWAY
What does D2 receptor agonist inhibit?
INHIBIT adenylate cyclase to INHIBIT the INDIRECT PATHWAY
What does all DA receptor agonist stimulate?
All directly stimulate postsynaptic D2 receptors
Used as monotherapy in EARLY PD
- Adjunctive therapy to DDCI for patients with adv/mod PD
- Reduces ‘on/off motor fluctuations’ in PD patients on long term L-DOPA therapy and may slow disease progression
What are the DA receptor agonist?
Pramipexole
Ropinirole
Apomorphine
all cause sleep attacks
How are DA receptor agonist used?
Monotherapy in Early PD and adjunct in Late PD.
What are the characteristics of Pramipexole?
Preferential affinity for D2 and D3, but also binds D4 receptors.
- No binding AT D1 RECEPTORS - Possibly neuroprotective – scavenges H2O2
What are general characteristics of Ropinirole?
Higher affinity for D3 than D2 or D4 receptors
- Effective in patients with MILD DISEASE
-
What are the side effects of pramipexole?
- Side Effects: sleep attacks; Dopamine Dysregulation Syndrome –
impulse control disorder (chronic); abrupt d/c - WITHDRAWAL
What are the side effects Ropinirole?
- Side Effects: Orthostatic hypotension - - D2-mediated NE response-decrease in peripheral vascular resistance (i.e, edema)
- Metabolized by CYP1A2- WATCH enzyme INDUCERS or INHIBITOR
What are the general characteristics of apomorphine?
Low affinity for postsynaptic D2 receptors in striatum
S.C. injection - temporary relief of “off” periods of akinesia
What are side effects of Apomorphine?
Side effects: dyskinesias, drowsiness, sweating, hypotension
