Shared Flashcard Set

Details

Exam #3 - Drugs for Treatment of Parkinson's Disease
N/a
36
Pharmacology
Graduate
10/21/2009

Additional Pharmacology Flashcards

 


 

Cards

Term
Parkinson's Disease
Definition
progressive, degenerative disease with onset usually after 50 yrs of age; Symptoms: tremor (resting tremor, "pill rolling" movement), muscular rigidity ("cogwheel" rigidity, "masked" facial expression), bradykinesia, akinesia (slowed purposeful movements, difficulty in initiating or stopping movements), postural & gait defects ("simian posture", "downhill walk")
Term
Reason for Parkinsonian symptoms
Definition
alteration of dopamine-ACh balance in striatum; a relative deficiency of dopaminergic activity in relation to ACh; due to death of dopaminergic neurons in nigrostriatal dopamine pathway
Term
Drugs that enhance dopaminergic activity - raise levels of dopamine
Definition
l-DOPA (Larodopa; Sinemet, Stalevo) - dopamine precursors converted to DA; selegiline/deprenyl (Eldepryl) & rasalagine (Azilect) - inhibit metabolism of DA by MAO-B; entacapone (Comtan) - inhibits metabolism (breakdown) of DA by COMT;
Term
Drugs that enhance dopaminergic activity - stimulate post-synaptic dopamine receptors
Definition
bromocryptine (Parlodel) & pergolide (Permax) - ergot derivatives; pramipexole (Mirapex) & ropinirole (Requip) - newer, non-ergot dopaminergic agonists
Term
Drugs that enhance dopaminergic activity - stimulate release of dopamine
Definition
amantadine (Symmetrel)
Term
Drugs that reduce cholinergic activity - centrally acting antimuscarinics
Definition
benztropine (Cogentin), trihexiphenidyl (Artane), & diphenhydramine (Benadryl)
Term
Chemistry & Mode of Action of l-DOPA (Larodopa, Sinemet)
Definition
amino-acid precursor of dopamine that is transported to brain & converted to dopamine
Term
Pharmacokinetics of l-DOPA (Larodopa, Sinemet)
Definition
variable absorption in GI; enters brain by active transport amino acid pump; metabolized to form DA by DOPA decarboxylase in brain & periphery; addition of a peripheral DOPA-decarboxylase inhibitor (Carbidopa) significantly reduces metabolism of DOPA to DA in periphery (reduction in dose of l-DOPA by 75% & greatly decreases severity of peripheral side effects)
Term
Therapeutic Effects of l-DOPA (Larodopa, Sinemet)
Definition
takes 3-4 wks to see full effect; 15% of pts are symptom free, 60% will be significantly improved, 25% show no improvement; therapeutic effects become less pronounced as disease progresses; does not halt the progression of disease, but becomes less effective as disease progresses
Term
Side Effects of l-DOPA (Laradopa, Sinemet)
Definition
nausea & vomiting (occurs in 80% of patients); cardiovascular effects: postural hypotension, tachycardia, arrhythmias; behavioral effects: depression, psychotic reactions, hallucinations, nightmares, euphoria, mood & personality changes, increased libido, release of inhibitions, compulsive behavior; Extrapyramidal Motor Symptoms: choreiform movements; Endocrine Effects: decreased levels of prolactin;
Term
clozapine (Clozaril)
Definition
atypical antipsychotic that is preferred in managing psychiatric effects of l-DOPA; unfortunately, it is also associated with agranulocytosis
Term
Ways to minimize nausea & vomiting side effects of l-DOPA
Definition
minimize incidence of this side effect by giving l-DOPA in divided doses after meals or by building up total daily dose gradually; since CRTZ is located outside of the BBB, concurrent administration of carbibidopa (Sinemet) significantly reduces incidence & severity
Term
Concurrent administration of carbidopa with l-DOPA
Definition
decreases significantly the frequency & severity of side effects caused by just l-DOPA
Term
Miscellaneous Effects of l-DOPA
Definition
precipitation of glaucoma, precipitation of gout, hot flashes, taste & smell disturbances, elevation of liver enzymes, positive Coomb's test, blood dyscrasias, exacerbation of malignant melanoma
Term
Contraindications of taking l-DOPA
Definition
cardiac arrhythmias, psychosis, melanoma, glaucoma, active peptic ulcer disease
Term
Major Drug Interactions with l-DOPA
Definition
interacts with: pyridoxine - enhancement of extracerebral metabolism decreases therapeutic effects; antipsychotics (DA antagonists) - inhibit effects; MAO inhibitors - hypertensive crisis; tricyclic antidepressants - hypertensive crises
Term
carbidopa (Lodosyn, Sinemt [+ l-DOPA])
Definition
inhibits DOPA decarboxylase in periphery but does not enter brain, permits reduction in dose of l-DOPA, thus reducing some of its side effects
Term
Sinemet =
Definition
carbidopa + l-DOPA
Term
bromocryptine (Parlodel) & pergolide (Permax)
Definition
ergot derivatives that act as relatively nonspecific DA receptor agonists; less effective than l-DOPA in treatment of Parkinson's disease; use in pts who do not tolerate or respond to l-DOPA, also used as therapeutic effects of l-DOPA diminish;
Term
Side Effects of bromocryptine (Parlodel) & pergolide (Permax)
Definition
nausea & vomiting, postural hypotension, mental disturbances (confusion, agitation, hallucinations, seizures), choreiform movements, endocrine disturbances (due to inhibition of prolactin)
Term
ropinirole (Requip) & pramipexole (Mirapex)
Definition
newer non-ergot dopaminergic agonists; approved for use in both early & late stage parkinsonism, used increasingly as first line drugs; also used in treatment of "restless leg syndrome"
Term
Side Effects of ropinirole (Requip) & pramipexole (Mirapex)
Definition
choreiform & dyskinetic movements, nausea, dizziness, confusion, sedation, behavioral changes, hallucinations
Term
pramipexole (Mirapex)
Definition
newer non-ergot dopaminergic agonist that may have antioxidant & neuroprotective effects which may be beneficial in slowing progression of Parkinson's Disease
Term
amantadine (Symmetrel)
Definition
originally used as an antiviral agent; stimulates release of DA from nerve endings; less effective than l-DOPA but more effective than anticholinergic drugs; may potentiate actions of l-DOPA
Term
Side Effects & Toxicities of amantadine (Symmetrel)
Definition
mental disturbances, hyperexcitability, ataxia, confusion, convulsions, choreiform movements, excreted by kidney - may require dosage adjustments in pts with impaired renal function
Term
selegiline/deprenyl (Eldepryl)
Definition
selectively inhibits MAO-B & prevents breakdown of dopamine in CNS; used as a supplement to l-DOPA, particularly in latter stages of Parkinsons; initial reports indicated it may slow progression of Parkinson's possibly inhibiting conversion of MPTP to neurotoxic metabolites but recent studies have not confirmed the earlier results
Term
Side Effects of selegiline/deprenyl (Eldepryl)
Definition
tremor, dyskinesias, choreiform movements, hallucinations, agitation, behavior & mood changes, nausea, weight loss, "Cheese toxicity" with tyramine seen at high doses
Term
entacapone (Comtan) & tolcopone (Tasmar)
Definition
newer drugs that inhibit metabolism of DA & l-DOPA by COMT; approved for use in conjunction with l-DOPA & l-DOPA + carbidopa for treatment of parkinson's disease; main side effects are due to increased levels of dopamine (hallucinations, nausea, hypertension)
Term
Stalevo (l-DOPA + carbidopa + entacapone)
Definition
new combination product used in treatment of Parkinson's Disease; has l-DOPA + carbidopa + entacapone
Term
benztropine (Cogentin) & trihexyphenidyl (Artane)
Definition
anticholinergics that may be effective in mild parkinsonism, usually more effective against tremor than rigidity; drugs of choice for treatment of iatrogenic Parkinsonism from DA antagonists
Term
Side Effects of benztropine (Cogentin) & trihexyphenidyl (Artane)
Definition
automatic - dry mouth, dry hot skin, hyperthermia, constipation, urine retention, loss of visual accomodation, tachycardia; behavioral - sedation, confusion, memory impairment; drug interactions with CNS depressants - alcohol, sedatives, opioids, muscle relaxants
Term
diphenhydramine (Benadryl)
Definition
antihistamine used to treat Parkinsonism primarily due to its anticholinergic activity
Term
Treatment of Mild to Moderate Symptoms of Parkinson's Disease
Definition
amantadine, dopamine agonists, MAO-B inhibitors, or anticholinergics may be adequate; pramipexole (Mirapex) and ropinirole (Requip) are becoming increasingly popular first line drugs
Term
Treatment of Moderate to Severe Symptoms of Parkinson's Disease
Definition
l-DOPA and carbidopa with or without entacapone
Term
Treatment of non-responsive patients with Parkinson's
Definition
add a dopamine agonist, selegiline, amantadine, or anticholinergics
Term
Huntingdons Disease
Definition
autosomal dominant with onset in middle-age; progressive deterioration; many of extrapyridal motor symptoms are similar to those seen in tardive dyskinesia; effects of treatment have focused on: decreasing dopaminergic activity (antipsychotics), enhancing effects of GABA (benzodiazepines), or ACh (physostigmine, rivastigmine)
Supporting users have an ad free experience!