Parkinson disease (dopamine receptor agonists) Flashcards
Dopamine receptor agonists used in PD - 5 drugs
Bromocriptine Pramipexole Ropinirole Rotigotine Apomorphine
Dopamine receptor agonists - MOA
Directly activate dopamine D2 receptors in the striatum.
Inhibition of the indirect neuronal pathway from the striatum to the thalamus, and increase thalamic stimulation of the motor area of the cortex.
When are the dopamine receptor agonists useful and why?
Advanced cases of PD.
Do not require functional dopaminergic neurons.
Bromocriptine - MOA
D2-agonist, D1-antagonist
Bromocriptine - indications
Adjunct to levodopa.
Type 2 DIA
Bromocriptine - adverse effects
Confusion, hallucinations, sedation, vivid dreams, dyskinesias.
Decreased prolactin levels.
Dry mouth, nausea, orthostatic hypotension.
Which dopamine receptor agonists activates both D2 and D3 receptors?
Pramipexole
Rotigotine
Which drugs for PD are also indicated for restless leg syndrome?
Pramipexole.
Ropinirole
Pramipexole, ropinirole - adverse effects
Dizziness Hallucinations Insomnia Nausea Vomiting Sedation
Pramipexole - interactions
Cimetidine increases serum levels
Ropinirole - MOA
Selective D2-receptor agonist.
Ropinirole - interactions
Ciprofloxacin increases serum levels
Ropinirole, rotigotine, pramipexole - indications
Delay need for levodopa in early stages of PD. Advanced stages – reduce off period. Monotherapy
Rotigotine - contraindications
Sulfite sensitivity
Apomorphine - MOA
Dopamine receptor agonist that is chemically related to morphine
Apomorphine - indications
Acute, intermittent hypomobility episodes in advanced PD.
Apomorphine - adm
Injection only
Centrally acting ACh receptor antagonists used in PD
Benztropine
Trihexyphenidyl
Benztropine - MOA
Like all central antiACh, it decreases the relative excess of ACh and has antihistamine activity.
In addition it inhibits neuronal reuptake of dopamine.
Centrally acting ACh receptor antagonists - indictions in PD
Adjunct therapy for PD.
Most effective for reducing tremor.
Reduce parksonian symptoms caused by dopamine receptor antagonists.
Centrally acting ACh receptor antagonists - adverse effects
Agitation Confusion Constipation Dry moth Delirium Memory loss Urinary retention Tachycardia
Centrally acting ACh receptor antagonists - interactions
Additive anticholinergic effect with antihistamines and phenothiazides