Parkinson's Drugs Flashcards
Dopaminergic Therapies
List of drugs for Parkinson’s Disease
Dopamine Agonists
1. Levodopa/Benserazide
2. Levodopa/Carbidopa
Ergot-derived Dopamine Agonists: Bromocriptine
Non-ergot derived Dopamine Agonists:
1. Ropinirole
2. Pramipexole
3. Rotigotine
Irreversible MAO-B Inhibitor:
1. Selegiline
2. Rasagiline
Reversible COMT Inhibitor: Entacapone
NMDA Antagonist: Amantadine
Other Combination medications: Stalevo (Levodopa, Carbidopa, Entacapone)
Levodopa / Carbidopa Formulations used mainly in NUH and Max dosing
250/25 mg Tablet (Credanil)
Max dose: 8 tablets/day (Levodopa 2 g/day, Carbidopa 200 mg/day)
Levodopa/Benserazide Formulations used mainly in NUH
250 mg Tablet (Madopar)
Max dose: Levodopa
- 1200 mg/day for 1st year (6 tabs/day)
- 600 mg/day for subsequent years (3 tabs/day)
Counseling points for levodopa: How to take?
- Empty stomach (But can take with light snacks if irritated)
- Take on time to maintain the effect of medication
- Avoid high-protein diet while taking levodopa
- Other DDIs:
- Space apart 2 hours: Iron, pyridoxine
- Alternatives to consider for Metoclopramide, sulpiride
Counseling points for levodopa: ADRs?
- Orange coloration in body fluids (Harmless)
- Low BP
- Uncontrolled movement (On-off phenomenon, wearing off effect)
- Nausea, vomiting
What is the role of benserazide and carbidopa?
Prevent peripheral conversion of levodopa in the bloodstream so that more levodopa can enter the brain
This also reduces the side effects of nausea, vomiting
Ropinirole formulation and dosing
Form:
- 0.25 mg, 1 mg, 2 mg Tablets
- PR 2 mg, 4 mg Tablet (Requip PD)
IR: 0.25 mg TDS initially, then increase every 7 days
Max: 24 mg/day, 3 divided dose
Usual dose: 12 to 16 mg/day
Pramipexole formulation and dosing
Form
- 0.125 mg (Immediate)
- 0.375 mg (Extended)
IR: 0.125 mg TDS increase every 7 days up to 4.5 mg/day
ER: 0.375 mg QD up to 4.5 mg/day
Rotigotine Formulation and Dosing
Formulation
2 mg/24 hours
4 mg/24 hours
6 mg/24 hours
8 mg/24 hours
Dosing:
Early stage: Start with 2 mg
Advanced-stage: Start with 4 mg
Do not discontinue abruptly, decrease by 2 mg/24 h EOD
Bromocriptine Formulation and Dosing
Form: 2.5 mg Tablet
Dosing:
- Usual PD dose: 1.25 mg BD then 2.5 mg QD in 2-4 week interval
- Absolute max dose: 100 mg/day
ADRs of dopamine agonists (ergot/non-ergot)
Dopaminergic:
1. Nausea, vomiting
2. Orthostatic hypotension
3. Leg or arm swelling
Non-dopaminergic:
1. Hallucination, agitation
2. Compulsion (Urges)
3. Sleep attacks (Sudden)
MAO-B Inhibitors Place in therapy and dosing
Selegiline 5 mg tablets (Max: 1 tab BD)
Indication:
- PD adjunct
- PD monotherapy in young
- MDD
Rasagiline 1 mg tablets (Max: HALF to 1 tab QD)
Indication:
- PD adjunct
- PD monotherapy
What is the special point about selegiline dosing, relating to the ADR?
Take one dose in the morning and one in the afternoon (Liver metabolism to amphetamine causing difficulty sleeping)
What are the other ADRs of selegiline and the rationale?
MAO plays a major role in breaking down DA, 5HT, NE and epinephrine
- Nausea, abdominal pain, constipation, diarrhea (5HT)
- Low BP (NE)
- Dry mouth
Rare: Hallucinations
Entacapone formulation, place in therapy and dosing
Form: 200 mg Tablet
Indication: PD adjunct to levodopa (increase the effect of levodopa)
Maximum: 1600 mg/day
May need to reduce L-dopa dose