Parkinson drugs Flashcards
what is Levodopa typically used for in Parkinson Disease
to control bradkinetic symptoms
MOA of Levodopa
converted to dopamine by DOPA decarboxylase at the presynaptic neuron to stimulate D2 receptors
Side effects of Levodopa (alone)
- GI: Anorexia, N/V
- CVS: Arrhythmias. tachycardia, postural hypotension
- Behavior: depression, anxiety, agitation, insomnia, confusion, hallucinations, nightmares, euphoria
- choreoathetosis of the face and distal extremities
- wearing off/ off and on phenomena
- mydriasis may precipitate glaucoma, gout, and taste abnormalities
- brown secretions
- peripheral neuropathies
contraindications of Levodopa(alone)
Psych patients (may exacerbate psychosis)
Angle closure glaucoma (may exacerbate mydriasis)
Peptic ulcer disease
melanoma
interactions of Levodopa
antacids decrease bioavailability
ACh drugs and antipsych drugs may decrease serum levels/ effects
combination with MAOIs can cause HTN crisis and hyperpyrexia
B6 increases metabolism
can be antagonized by phenothiazines when not used with carbidopa
MOA of carbidopa
reduces peripheral conversion of Levodopa to dopamine and inhibits aromatic amino acid decarboxylase
does Carbidopa cross the BBB
no
AChR antagonists used in Parkinson Disease
Benztropine
Trihexyphenidyl
When are AChR antagonists used for Parkinson Disease?
patients who are 65 or younger and have a disturbing tremor, but no gait disturbance or bradykinesia
MOA of AChR antagonists
inhibits excitatory cholinergic neurons to decrease the concentration of ACh
Side effects of Benztropine and Trihexyphenidyl
Agitation
confusion
Constipation
Delerium
Dry mouth
Memory loss
urinary retention
tachycardia
Cautions and contraindications of using AChR antagonists
Caution: patients with closed-angle glaucoma
Contraindications: memory impaired, confused, hallucinating patients
Interactions with AChR antagonists
has additive anticholinergic effects with antihistamines and phenothiazines
What are the MAO-B Inhibitors and what are they used for
Selegiline, Rasagiline, Safinamide
Reduces mild on-off/ wearing off phenomena
for patients with declining or fluctuating response to Levodopa
Decreases free radicals and inhibits disease progression
MOA of MAOI-B Inhibitors
selectively and irreversibly inhibits MAO-B to increase dopamine in basal ganglia
MAO-B Inhibitor side effects
confusion
dyskinesias
hallucinations
hypotension
insomnia
nausea
Interactions of MAO-B Inhibitors
If taken with Meperidine: causes serotonin syndrome
With foods rich in tyrosine: hypertensive crisis
Rasagiline may enhance adverse effects of Levodopa
Most potent MAO-B inhibitor to prevent MPTP induced Parkinsonism
Rasagiline
The difference in the COMT inhibitors and what are they used for
Entacapone: peripheral COMT inhibitor
Tolcapone: Central COMT inhibitor
patients taking Levodopa who have fluctuations
MOA of COMT inhibitors
inhibits COMT to decrease the metabolism of dopamine
Side effects of COMT Inhibitors
Nausea
diarrhea
orange secretions
Contraindications of Tolcapone
Liver failure
only use if patient is unresponsive to other therapies
Interactions of COMT Inhibitors
decreases Levodopa clearance to increase the overall concentration in circulation
What is Amantadine used for and what is its MOA
Influenza A and early/ late-stage Parkinsonism
NMDA antagonist that potentiates dopaminergic function by influencing the synthesis, release and reuptake of dopamine
Side effects of Amantadine
dry mouth
hypotension
Livedo reticularis
nausea
restlessness
sedation
vivid dreams
What drugs can potentiate the effects of Amantadine
Benztropine
Trihexyphenidyl
What kind of disorders are dopamine receptor agonists most commonly associated with
impulse control disorders
which dopamine receptor agonists prefer D2 receptors and which prefer D3
D2: Bromocriptine and Ropinrole
D3: Pramipexole
Apomorphine is a general dopamine agonist
Side effects of Bromocriptine
confusion
decreased prolactin
dry mouth
dyskinesias
hallucinations
nausea
orthostatic hypotension
sedation
vivid dreams
suppression of lactation
Interactions of Bromocriptine
cardiac valve fibrosis
pulmonary fibrosis
When is Pramipexole used
advanced parkinson disease
Side effects of Pramipexole and Ropinrole
dizziness
hallucinations
insomnia
interactions of Pramipexole
Cimetidine increases levels
Which dopamine receptor agonist is contraindicated with breastfeeding
Ropinrole
What is apomorphine used for
rescue during off periods of akinesia in patients on dopaminergic therapy
Side effects of Apomorphine
N/V
Dyskinesia
Drowsiness
Hypotension
Chest pain
component of synthetic drugs that cause parkinsonism
MPTP
MOA of MPTP
inhibits mitochondrial oxidation, causing irreversible destruction of nigrostriatal dopaminergic neurons
