| Dopaminergic Agents |
| Precursor amino acid:
levodopa |
|
Dyskinesia, dystonia,
hallucinations, hyperkinesia, dizziness, fatigue, abdominal pain, constipation,
diarrhea, nausea, vomiting, cardiac abnormalities, orthostatic hypotension,
discolored urine |
| Carbidopa-levodopa
(Sinemet) |
200–2000 mg/day, divided
three times daily |
Increase by 1 tablet
every day or every other day to a maximum of 8 tab/day |
| Controlled release
(Sinemet CR) |
200–1400 mg/day, divided
twice daily |
Increase by 1 tablet
every 3 days to a maximum of 8 tab/day |
| Madopar CR 100/25mg
(L-dopa and benserazide) |
1–8 tabs 4–6 times
daily |
Introduce
gradually |
| Carbidopa-levodopa-entacapone (Stalevo) |
12.5 mg
carbidopa with 50 mg levodopa and 200 mg entacapone twice daily |
Used when other
medications become less effective |
| Increase slowly to a
maximum of 8 tab/day |
| Dopamine agonists |
|
Somnolence, sudden onset
of sleep (caution with driving), confusion, hallucinations,
hypotension |
| Bromocriptine |
2.5–60 mg/day |
Adjust every 2 weeks
|
| |
1.25 mg twice daily |
|
| Pramipexole |
0.125 mg three times
daily |
Adjust every week up to a
maximum of 1.5 mg three times daily |
| Ropinirole |
0.25 mg three times
daily |
Adjust every week up to a
maximum of 12–16 mg |
| Monamine oxidase B
inhibitors |
|
Sleep disturbance,
light-headedness, nausea, abdominal pain, confusion, hallucinations |
| Selegiline
(deprenyl) |
5 mg at breakfast and
lunch |
No dosage titration
required |
| Indirect agonists |
|
Hallucinations, dry
mouth, livedo reticularis, ankle swelling, myoclonic encephalopathy in setting
of renal failure |
| Amantadine |
100–300 mg/day |
Avoid in patients with
cognitive impairment |
| Catecholamine-O-Methyltransferase (COMT) inhibitors |
|
Effective only with
levodopa and given in combination to reduce levodopa-induced dyskinesias;
enables levodopa dosage to be reduced, increase levodopa bioavailability, and
prolongs its half-life; reduces "off" time and increases "on" time |
| Tolcapone |
300–600 mg/day, or 100 or
200 mg three times daily |
Worsening of
levodopa-induced dyskinesias (as evidenced by improvement with decrease in
levodopa dosage), diarrhea, nausea, vivid dreams, visual hallucinations, sleep
disturbances, daytime drowsiness, headache, hepatotoxicity |
| Entacapone1 |
200 mg, twice to eight
times daily, with each dose of carbidopa-levodopa |
| Other Drug Classes |
| Anticholinergics2 |
|
Confusion, sleepiness,
blurred vision, constipation |
| Trihexyphenidyl |
2–15 mg/day |
|
| Biperiden |
1–8 mg/day |
Avoid in patients with
cognitive impairment or patients older than 65. |
| Novel neuroleptics |
|
Used for psychosis and
unusual tremor |
| Clozapine |
12.5–100 mg/day |
Fatal neutropenia,
somnolence |
| Quetiapine |
12.5–100 mg/day |
Somnolence, potential
aggravated parkinsonism |
| Miscellaneous |
|
|
| Amitriptyline |
10–50 mg/day at
bedtime |
Sleep fragmentation, dry
mouth, forgetfulness, blurred vision, constipation |
| Baclofen |
10–80 mg/day |
Dystonic cramps,
sleepiness, dizziness |