movement disorder pharm Flashcards
(23 cards)
L-DOPA moa
immediate precursor to DA, replenishes DA stores in the remaining DA terminals in the striatum
L-DOPA pharmacokinetics
concentrations peak quickly; converted in the periphery and brain to DA by L-ADD; must be given in high doses when used alone, usually administered with carbidopa (L-AAD inhibitor)
L-DOPA monotherapy adverse effects
GI disturbances, CV dysfunction - arrhythmias (tachy, a. fib, and extrasystoles), orthostatic hypotension
L-DOPA + carbidopa adverse effects
behavioral problems and dyskinesias
DA replacement negative interactions
vitamin B6 increases metabolism, MAO-A inhibitors can increase risk of HTN crises
DA replacement contraindications
psychotic patients, glaucoma, cardiac disease, peptic ulcer, and melanoma
Dopamine agonists
bromocriptine, apomorphine, pramipexole (D2 selective + free radical scavenger), ropinirole (D2 selective)
Ropinirole pharmacodynamics
metabolized by CYP 1A2
Amantadine
antiviral agent that appears to enhance release and possibly DA synthesis; may also inhibit uptake.
amantadine adverse effects
restlessness, depression, agitation, irritability, insomnia, excitement, hallucinations, and confusion; overdose may produce psychosis
amantadine contraindications
patients with Hx seizures or heart failure
selegiline MOA
selective MAO-B inhibitor - slows breakdown of DA; metabolites increase DA release and may be neuroprotective and reduce PD progression by inhibiting MAO-B mediated formation of free radicals
selegiline indications
used in patients whose responsiveness to L-DOPA has declined
selegiline negative interactions
do not take with meperidine, TCAs or SSRIs
rasagiline moa
potent inhibitor of MAO-B approved for combined therapy with levodopa in late-stage PD or alone in early PD
entacapone and tolcapone moa
selective inhibitors of COMT, prolonging the action of L-DOPA, reducing the production of 30MD which may compete with L-DOPA for transport carriers, increasing L-DOPA bioavailability
muscarinic antagonists used for PD
benztropine, diphenhydramine, trihexyphenidyl
antipsychotics MOA in HD treatment
ability to block D2 receptors, increasing indirect pathway activity
selegiline adverse effects
may potentiate adverse effects of L-DOPA
anticholinergic moa in PD treatment
blocks cholinergic activation in the striatum, altering the DA/ACh balance
anti-cholinergic contraindications
BPH, obstructive bowel disease, glaucoma; avoid use of TCAs or antihistamines
VMAT inhibitors (drugs)
reserpine and tetrabenazine
Dopamine antagonists (drugs)
chlorpromazine and haloperidol
