Parkinsonism Flashcards
L-Dopa- Mech of Action
DOPAMINE PRECURSOR
CROSSES BBB, IS CONVERTED TO L-DOPA, IS THEN TRAPPED IN THE BRAIN
L-Dopa- Absorption, Distribution
Low bioavailability
L-Dopa- Elimination
L-Dopa half life 1-3hrs
Increased by an additional 1-3hrs by addition of carbidopa
L-Dopa- Clinical Use
Given in combination
Parkinson’s (especially the bradykenisia)
Elevate growth hormone release
Hyperprolactinemia
L-Dopa- adverse effects/contraindications
ON-OFF PHENOMENA (END DOSE AKINESIA, FLUCTUATION IN RESPONSE)
Dyskinesia (tics, grimacing, bobbing)
Behavioral (organic brain syndrome- confusion, delirium; hallucinations, paranoia, mania, insomnia, anxiety, nightmares, depression)
L-Dopa- Drug Rxns
Hypertensive crisis when taken with MAO inhibitors (Phenelzine, but not Selegine)
Carbidopa- Mech of Action
DOPAMINE PERIPHERAL DEGRADATION INHIBITOR.
DOPA DEBARBOXYLASE INHIBITOR.
Carbidopa- Clinical Use
Given in combination
Parkinson’s (especially the bradykinesia)
Elevate growth hormone release
Hyperprolactinemia
Carbidopa- Adverse Effects/Contraindications
ON-OFF PHENOMENA (END DOSE AKINESIA, FLUCTUATION IN RESPONSE)
Dyskinesia (tics, grimacing, head bobbing)
Behavioral (organic brain syndrome- confusion, delirium)
hallucinations, paranoia, mania, insomnia, anxiety, nightmares, depression
Bromocriptine- Mech of Action
D2 AGONIST
PARTIAL D1 ANTAGONIST
Bromocriptine- Clinical Use
Parkinson’s
Hyperprolactinemia, pituitary adenoma
Bromocriptine- Adverse Effects/Contraindications
HYPOTENSION
ARRHYTHMIAS
DYSKINESIAS
PSYCHOLOGICAL DISTURBANCE (including increase in impulse control disorders- i.e. gambling)
anorexia, nausea, vomiting, colicky abdominal pain
less “on-off” phenomena
Ropinirol- Mech of Action
D2 AGONIST
Ropinirol- Clinical Use
Parkinson’s
Ropinirol- Notes
Newer drugs= more specific, longer half lives, less side effects
Ropinirol- Adverse Effects/Contraindications
Nausea
Pramipexole- Mech of Action
D3 Agonist
Pramipexole- Clinical Use
Parkinson’s
Amantadine- Mech of Action
RELEASE DA FROM TERMINALS
ANTI-VIRAL
Amantadine- Clinical Use
Early Stage Parkinson’s
Amantadine- Adverse Effects/Contraindications
CNS effects restlessness insomnia inrritability confusion enhances anti-choinergic effects
Selegaline, Rasgeline- Mech of Action
MAO-B INHIBITOR= DECREASED DA DEGRADATION
Selegaline, Rasgeline- Clinical Use
Early stage Parkinson’s
later stages with L-DOPA to reduce “on-off” phenomena
Selegaline, Rasgeline- Notes
metabolized to amphetamine (a DA and NE releaser and uptake inhibitor)
