Entacapone
COMTAN
Pronunciation: en-TA-ka-poen
“Compton into Capone”
What it isCOMT inhibitor blocking peripheral levodopa breakdown; Parkinson disease with wearing-off.
Why this oneUnlike tolcapone it stays peripheral and avoids liver monitoring; unlike opicapone it accompanies each levodopa dose.
What limits itUseless without levodopa. Diarrhea can end treatment, while orange urine discoloration is harmless.
Pearls
- Can worsen dyskinesia; lower the levodopa dose when adding.
- Also sold combined with carbidopa/levodopa (Stalevo).
Entacapone prescription history
Animated chart of estimated U.S. prescriptions per year, Parkinson medicines (1948–2026). Entacapone enters in 1999 (estimated).
FDA-approved for
- Parkinson disease (1999)
Principal riskUseless alone; must accompany every levodopa dose
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityOrthostasis, hallucinations, dyskinesia and impulse-control symptoms; abrupt withdrawal can be hazardous.
FDA label
Read the full label on DailyMed ↗
NO BOXED WARNINGS
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Parkinson's disease — adjunct to levodopa/carbidopa | adult | 200 mg with each levodopa/carbidopa dose | 200 mg with each levodopa/carbidopa dose | 8 doses/day (1,600 mg/day) |
Renal Undefined
Hepatic Caution — entacapone AUC and Cmax approximately doubled in documented liver disease
Limited clinical experience with daily doses above 1,600 mg.
Instructions
- Always administer with levodopa/carbidopa — entacapone has no antiparkinsonian effect of its own
- May take with or without food
- Can be combined with immediate- or sustained-release levodopa/carbidopa
- Levodopa dose reduction (average ~25%) often needed, especially if levodopa >=800 mg/day or preexisting moderate-severe dyskinesia
- Withdraw slowly — rapid withdrawal may cause re-emergence of PD signs and an NMS-like syndrome (hyperpyrexia, confusion); adjust other dopaminergic therapy on discontinuation
Available strengths
- tab 200 mg
Cautions
- Ordinarily do not combine with non-selective MAOIs (phenelzine, tranylcypromine) — both catecholamine pathways inhibited; selective MAO-B inhibitors (selegiline) may be used
- Caution with COMT-metabolized drugs (epinephrine, isoproterenol, norepinephrine, dopamine, dobutamine, methyldopa, apomorphine) — increased heart rate, arrhythmias, blood-pressure changes
- Falling asleep during activities of daily living / somnolence — caution driving
- Hypotension, orthostatic hypotension, syncope
- Hallucinations and psychotic-like behavior; avoid in major psychotic disorder
- Impulse-control and compulsive behaviors (gambling, sexual, spending urges)
- Diarrhea — may signal drug-induced microscopic (lymphocytic) colitis; discontinue if prolonged
- May cause or exacerbate dyskinesia (may persist despite levodopa reduction)
- Rhabdomyolysis reported; hyperpyrexia/confusion (NMS-like) with rapid withdrawal
Adverse reactions
- Dyskinesia (25%), hyperkinesia (10%)
- Nausea (14%), diarrhea (10%), abdominal pain (8%), vomiting (4%), dry mouth (3%)
- Urine discoloration (10%)
- Dizziness (8%), somnolence, anxiety
- Postmarketing: hepatitis with mainly cholestatic features
Pregnancy Category C — fetal variations and eye anomalies in animal studies; use only if potential benefit justifies fetal risk.
Lactation Excreted in rat milk; unknown in humans — use caution.
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 200 mg | tab | per unit | $0.32/ea | offered |
Generic entry2012
Open Entacapone in the interactive console ↗
Memory aids: interaction avatars
Open Entacapone in the interactive console ↗
Self-check
- Does entacapone help without levodopa?
No. - What harmless urine change can entacapone cause?
Orange discoloration.