Levodopa (Dopar)

Class

MOA

Pharm

Dopamine precursor drug

MOA: increases dopamine synthesis in the striatum

Pharm: Only 2% of dose reaches brain

Primary drug for Tx of Parkinsons

Levodopa (Dopar)

ADRs

Dose dependent N/V

Postural Hypotension

Psychosis

Dark sweat/urine

Dyskinesia

Dysrhythmias

Levodopa (Dopar)

↑ beneficial effects w/ carbidopa or prampexole

↓ effects w/ Vit B6 & antipsychotics

↑ toxicity w/ MAOI's

Pramipexole (Mirapex)

Class

MOA

Pharm

Dopamine Agonist (Dopaminergic)

MOA: binds selectivley to dopamine D₂ and D₃ receptors

Pharm: readily absorbed 

   Onset 1-2 hours

   Food reduces absorption

   Wide distribution and high [ ] in RBC's

Pramipexole (Mirapex)

ADR's

Orthostatic Hypotension

Nausea

Dizziness

Daytime Sleepiness

Insomnia

Weakness

Hallucinations

Sleep attacks

Impulse control behaviors

Pramipexole (Mirapex)

Drug interactions

Dosage

Route

Teaching

• Tagamet ↑ blood levels
• PO in divided doses
• May allow for reduction in Levodopa dose
• Fewer off times if pramipexole taken with levodopa
• May be taken w/ food for ↓ nausea

Levodopa/Carbidopa (Sinemet)

Class

MOA

Use

Combination agent

MOA: Carbidopa enhances effects of levodopa by preventing breakdown of levodopa

First line use for PD patients between 50-70 yoa

Levodopa/Carbidopa (Sinemet)

ADR's

Drug interactions

Dosing/route

↓ADR's because combination w/ carbidpoa allows dose of levodopa to be decreased.

↓ adverse effects

Interactions minimal due to ↓ levodopa dose

PO.  IR or SR dose. Initial dosing schedule can be intense must be strictly adhered to  (Q 2-3 hours)

Entacopone (Comtan)

Class

MOA

pharm

COMT Inhibitor

• Inhibits catechol-O-methyltransferase 
• ↑ half life & availability of Levodopa
• Used only in combination w/ levodopa/carbidopa

Pharm rapidly absorbed (PO) Q daily

peak 2hrs

excreted feces

T 1/2:  1.5-3.5 hours

Entacapone (Comtan)

ADR's

Drug interactions

• dyskenesia
• orthostatic hypotension
• nausea
• hallucinations
• sleep disturbances

Drug interactions: ↑ levels of levodopa, methyldopa, dobutamine & isoproterenol

Entacopone (Comtan)

Dosage

Teaching

PO Dose daily w/ sinemet

ED:

• Fewer on/off times expected
• Report SE's to MD immediately