Parkinson's Disease Flashcards
Classification of Parkinson’s
- idiopathic -> just get it
- latrogenic -> drug induced particularly in antipsychotics
- post-traumatic -> after brain injury
In those with parkinsons’s disease, there is more
ACh and less dopamine
Drugs that raise dopamine levels
- l-DOPA
- selegiline/deprenyl inhibits metabolism of dopamine by MAO-B
- entacapone inhibits COMT
Drugs that stimulate post-synaptic dopamine receptors
- bromocryptine, pergolide, pramipexole
Drug that stimulates release of dopamine
amantadine
Drugs that reduce cholinergic activity
centrally acting muscarinic antagonists
benztropine
diphenhydramine (BENADRYL)
addition of Carbidopa to l-DOPA can
reduce metabolism of DOPA to dopamine by about 75% and decreases severity of some peripheral side effects
Therapeutic effects of l-DOPA
- takes 3-4 weeks before full effect
- less pronounced effects as disesase progresses
Side effects of l-DOPA
- nausea and vomiting due to stimualtion of chemoreceptor trigger zone by dopamine
Cardiovascular effects of l-DOPA
postural hypotension
tachycardia
arrhythmias
Behavioral effects of l-DOPA
-psychotic rxns, hallucinations, nightmares, mood changes
- increased libido and release of inhibitions
antipsychotic clozapine effective for managing psychiatric side effects
Choreiform movements (writhing movements)
after long term therapy or when used with carbidopa
end of dose phenomenon
decline in blood levels of l-DOPA near the end of dosage interval
on-off phenomenon
can occur at any time in dosage interval and appears to be related to the progression of disease
effects minimized by using sustained release preparation or by adding COMT inhibitor or dopamine agonist
Contraindications of l-DOPA
- cardiac arrhythmias
- psychosis
- melanoma
- glaucoma
- active peptic ulcer disease
Sinemet =
carbidopa + l-DOPA
Bromocryptine
nonspecific DA receptor agonist
less effective than l-DOPA
Bromocryptine side effects
- nausea vomiting
- postural hypotension
- mental disturbances
- choreiform movements
Ropinirole, Pramipexole, and Rotigotine
newer non-ergot dopaminergic agonists that target D2 and D3 receptors
now being used as first line drugs
less severe side effects
Rotigotine is a new long-acting patch product
Amantadine (activity, side effects)
antiviral agent
stimualtes release of dopamine
side effects:
mental disturbances, choreiform movements
Selegiline
selectively inhibits MAO-B and prevents breakdown of dopamine in CNS
Entacapone and tolcopone
inhibit metabolism of dopamine and l-DOPA by COMT
provide more sustained blood level of I-DOPA
Anticholinergic drugs
effective in milk parkinsons
more effective agonist tremor than rigidity
side effects: dry mouth, constipation, dry hot skin, blurring of vision
