Parkinson's Flashcards
Most effective tx for Parkinson’s?
Levodopa
What do you give with Levodopa? Why?
Carbidopa.. Cuz levodopa is metabolized by L-AAD. Carbidopa inhibits L-AAD in the periphery but not in CNS –> need less levodopa dose & less AE’s
AE’s of levodopa monotherapy?
Arrhythmias, orthostatic hypoTN… and GI upset
Levodopa/Carbidopa AE’s?
Behavioral (give antipsychotics), hyperkinetic dyskinesias, may increase free radicals –> worsens Parkinsons
Describe the “On-Off” phenomenon
Levodopa works great sometimes and sometimes it sucks.. There is no rhyme or reason to this (it is not dose dependent & does not come from increased tolerance - according to UWorld)
Contraindications in levodopa?
Psychos, glaucoma, CV disease, PUD, melanoma. Also drug interaction w/ Vit B6
What Parkinson’s dz drugs are dopamine agonists?
- Apomorphine (NS)
- Bromocriptime (D2/some D1)
- Pramipexole (D2, free radical scavenger)
- Ropinirole (D2, CYP1A2)
* All Bros Prefer Rowdiness
Preferred initial therapy in Parkinson’s?
Dopamine agonists
What drug increases dopamine release?
Amantadine: an antiviral that treats the flu
**No effect on metabolism!!!
Contraindications with Amantadine?
Seizures, CHF
What drugs are dopamine metabolism inhibitors? (4 total drugs; 2 inhibiting each enzyme)
- MAO-B Inhs: Selegiline & Rasagiline
- COMT Inhs: Entacapone & Tolcapone
Which dopamine metabolism inhs are neuroprotective and not that effective when used alone?
The MAO-B’s: Selegiline & Rasagiline
What are the MAO-B’s (Selegiline & Rasagiline) metabolized to?
Amphetamine/methamphetamine
What drugs do the MAO-B’s (Selegiline & Rasagiline) interact with?
Meperidine, TCAs, SSRIs
What do COMT inhs do to levodopa?
Prolong its action & increase its bioavailability
*They also help reduce “ON-OFF”
Are the COMT’s (Entacapone & Tolcapone) protein bound?
Yes
Which COMT acts only peripherally?
Entacapone. Significant cuz no AE’s
Tolcapone acts peripherally and centrally thus it has AE’s. What are they?
Hepatic failure!!!
What Parkinson’s drugs are anticholinergic?
Block That Doo-doo:
Benztropine, Diphenhydramine, Trihexyphenidyl
CNS AE’s of the anticholinergics
sedation, confusion, hallucination, mood change
PNS AE’s of anticholinergics?
Opposite SLUDGEBBB
Contraindications of anticholinergics?
BOGAT*
BPH, OBD (organic brain disease), glaucoma, anti-histamines (1st generation), TCAs
What drug for Parkinson’s is a future drug that blocks L-type Ca channels?
Israpidine
