Movement Disorder Medications Flashcards
Levadopa MOA
Converted into dopamine after it crosses the blood-brain barrier thus increasing intraparenchymal levels of dopamine (dopamine precursor)
Side effects levadopa
Nausea/vomiting, dyskinesias, orthostatic hypotension
Why is carbadopa given with levadopa?
Reduce the GI side effects and reduce levodopa’s peripheral plasma breakdown
Is levodopa safe in pregnancy?
Yes
COMT inhibitors (tolcapone and entacapone) MOA
Reduces methylation of levodopa and dopamine, which increases levodopa’s half-life
What medication do COMT inhibitors need to be given with to work?
Levadopa
COMT inhibitor side effects
Severe diarrhea and discoloration of urine
MAO-B inhibitors (rasageline and selegiline) MOA
Decreases the catabolism of dopamine, resulting in a greater peak effect and less wearing off when used in combination with levodopa
When can MAO-B inhibitors be used as monotherapy?
Early PD
Side effect of MAO-B inhibitors
Tyramine heavy foods -> severe tachycardia and hypertensive crisis (can be fatal)
Serotonin syndrome - rare
Direct dopamine agonist (DDA) MOA
Agonists to the dopaminergic D2 receptors
DDA medications
Bromocriptine, pramipexole, ropinirole, rotigotine, and apomorphine
DDA side effects
First generation: cardiac valvulopathy
Impulse-control disorder, hallucinations, nausea, orthostatic hypotension, peripheral edema
Which DDAs are known to worsening driving drowsiness?
Pramipexole and ropinirole
If combined with levodopa, what symptoms can worsen with DDAs?
Dyskinesias
Amantadine MOA
Anti-dyskinetic effect by reducing the frequency of abnormal involuntary movements due to levodopa; helpful for resting tremor
N-methyl-d-aspartate (NMDA) receptor antagonist
Amantadine side effects
Livedo reticularis, confusion, hallucinations, ankle edema, constipation
When would anticholinergics (trihexyphenidyl and benztropine) be used for PD?
Patients younger than 60 because of cognitive concerns with tremor-predominant dysfunction, bradykinesia, postural instability, and/or rigidity
Side effects of trihexyphenidyl and benztropine?
Cognitive dysfunction, urinary retention, dry mouth, and GI disturbance
What is the antipsychotic of choice for PD-related psychosis?
Clozapine
* Preferential inhibition of dopamine receptors in the frontal lobe
* Side effects: bone marrow suppression
What is the only FDA approved medication specifically for Parkinson’s disease psychosis?
Pimavanserin
* Serotonin 5-HT2A receptor inverse agonist and antagonist
DBS only has effect on which symptoms of PD?
Motor symptoms
Neurosurgical interventions for PD
Targeting of the basal ganglia;
High-frequency stimulation (deep brain stimulation)
Lesioning (focused ultrasound)
Location for DBS placement
Ventral intermediate nucleus (VIM) of the thalamus (for tremor)
Globus pallidus interna (GPi)/subthalamic nucleus (STN) (tremor, bradykinesia, and rigidity)
