Prescription medication · COMT Inhibitor
entacapone
Also sold as Comtan. Entacapone is used to treat Parkinson's disease.
Data updated 2026-05-15
- 3,955
- FDA reportsLightly reported
- 3
- InteractionsFew interactions
- 1
- Recall record
What the data shows
entacapone (Comtan) is a prescription COMT Inhibitor, among the least-reported drugs the FDA tracks (3,955 FDA reports), with 3 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
entacapone (Comtan) is a prescription COMT Inhibitor. Entacapone is used to treat Parkinson's disease.
Entacapone is a medicine that helps people with Parkinson's disease. It is always used with levodopa and carbidopa to help reduce "wearing-off" symptoms.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.32/unit
Generic Available
Yes (5 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: ENTACAPONE 200 MG TABLET
Same CMS presentation as the headline generic unit price above (2 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: -23.3% vs prior release.
| Effective | NADAC / unit | vs prior | NDCs |
|---|---|---|---|
| February 21, 2024 | $0.4113/EA | - | 1 |
| December 18, 2024 | $0.3153/EA | -23.3% | 11 |
What it does
Entacapone is used to treat Parkinson's disease.
Common side effects
Uncontrolled movements, Urine discoloration, Diarrhea
Key warnings
If you suddenly stop taking entacapone or quickly lower the dose, your Parkinson's symptoms may get worse.
The sections below are summarized in plain English from entacapone's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Entacapone belongs to a class of drugs called COMT inhibitors. It works by blocking an enzyme called COMT, which breaks down levodopa in the body. By blocking COMT, entacapone helps levodopa work longer and more effectively.
Side Effects (from patient reports)
Based on 3,955 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for entacapone, by number of reports
- Dyskinesia
Dyskinesia
461 reports
- Hallucination
Hallucination
459 reports
- Fall
Fall
443 reports
- Death
Death
318 reports
- Parkinson^S Disease
Parkinson^S Disease
274 reports
- Confusional State
Confusional State
255 reports
- Gait Disturbance
Gait Disturbance
253 reports
- Tremor
Tremor
251 reports
- On And Off Phenomenon
On And Off Phenomenon
225 reports
- Somnolence
Somnolence
190 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for entacapone each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where entacapone sits
entacapone has more FDA adverse-event reports than 22% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is entacapone; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 3,955 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2003–2025.
Total Reports
3,955
Reports Mentioning Death
603
15.2% of reports — not proof of cause
Hospitalization Reports
1,340
Top Indication
Parkinson^S Disease
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DYSKINESIA | 461 |
| 2 | HALLUCINATION | 459 |
| 3 | FALL | 443 |
| 5 | DEATH | 318 |
| 6 | PARKINSON^S DISEASE | 274 |
| 7 | CONFUSIONAL STATE | 255 |
| 8 | GAIT DISTURBANCE | 253 |
| 9 | TREMOR | 251 |
| 10 | ON AND OFF PHENOMENON | 225 |
| 11 | SOMNOLENCE | 190 |
| 12 | CONSTIPATION | 188 |
| 13 | FATIGUE | 184 |
| 14 | NAUSEA | 184 |
| 15 | HALLUCINATION, VISUAL | 181 |
| 16 | DIZZINESS | 180 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
If you suddenly stop taking entacapone or quickly lower the dose, your Parkinson's symptoms may get worse. This could also cause a high fever and confusion. If you stop taking entacapone, your doctor should watch you closely and adjust your other medicines as needed. It is best to slowly lower the dose before stopping completely.
Known Drug Interactions
7 DRUG INTERACTIONS Drugs metabolized by COMT: use with caution ( 5.10 , 7.2 ) Anti-hypertensive agents: dose adjustment may be required ( 7.3 ) Tricyclic antidepressants: risk of hypertension and dyskinesia reported during concomitant use with carbidopa/levodopa ( 7.4 ) Dopamine D2 receptor antagonists, isoniazid, phenytoin, papaverine and iron salts: may reduce efficacy of carbidopa, levodopa and entacapone tablets ( 7.5 , 7.6 , 7.7 , 7.8 , 7.9 ) Drugs that interfere with biliary excretion, glucuronidation and intestinal beta-glucuronidase: dose adjustment of carbidopa, levodopa and...
Mechanism: Entacapone is designed to block the enzyme that breaks down levodopa, which helps the medicine stay in your system longer. This can increase the effects of the levodopa on your brain and body.
Product Clinical Comment on Concomitant Use [See Contraindications (4.1)] ; Predominant Effect/Risk [Hypertensive Reaction (HR) [See Warnings and Precautions (5.3)] ; or Serotonin Syndrome (SS) [See Warnings and Precautions (5.7)] ] Altretamine Use with caution If not otherwise specified in this table, consider avoiding concomitant use (see also information on medication-free intervals , use agent at the lowest appropriate dose, monitor for effects of the interaction, advise the patient to report potential effects, and be prepared to discontinue the agent and treat effects of the...
Mechanism: Using these medications together can cause a sudden, dangerous increase in blood pressure or a serious brain chemical imbalance. Both drugs affect how the body breaks down certain chemicals, leading to a risky buildup.
In an interaction study in healthy volunteers, entacapone did not significantly change the plasma levels of S-warfarin while the AUC for R-warfarin increased on average by 18% [Cl90 11% to 26%], and the INR values increased on average by 13% [Cl90 6% to 19%]. Nevertheless, cases of significantly increased INR in patients concomitantly using warfarin have been reported during the postapproval use of entacapone. Therefore, monitoring of INR is recommended when entacapone treatment is initiated or when the dose is increased for patients receiving warfarin.
Mechanism: Entacapone can increase the levels of warfarin in your system, which may cause your blood to become too thin.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
Can I take entacapone by itself?
What should I do if my urine turns orange-brown?
Can I drive while taking entacapone?
Will entacapone cure my Parkinson's disease?
Can I drink alcohol while taking entacapone?
What if I have liver problems?
Can entacapone interact with other medications I'm taking?
How long does it take for entacapone to start working?
What if I experience uncontrolled movements (dyskinesia)?
Is it okay to take with food?
What are the common side effects of entacapone?
Does entacapone interact with other medications?
What drug class is entacapone?
What pregnancy or breastfeeding source fields are listed for entacapone?
Has entacapone been recalled?
Active Recalls
Product mix up: complaint received that sealed medication bottle contained Carbidopa, Levodopa, and Entacapone film-coated tablets (37.5 mg/150 mg/200 mg) instead of labelled lower strength Carbidopa, Levodopa, and Entacapone film-coated tablets (25 mg/100 mg/200 mg).
Rising Pharma Holding, Inc.
Related Medications in COMT Inhibitor
Other drugs grouped near entacapone - same-class peers and common alternatives.
acamprosate
Campral
Acamprosate is a medicine that can help you stay away from alcohol if you are alcohol-dependent and have already stopped drinking.
Compare with entacapone →
alprazolam
Xanax
Alprazolam (Xanax) is a medication that can help you with anxiety and panic disorders.
Compare with entacapone →
amitriptyline
Elavil
Amitriptyline is a medicine used to treat depression.
Compare with entacapone →
amphetamine/dextroamphetamine
Adderall, Adderall XR
Adderall XR is a stimulant medicine.
Compare with entacapone →
aripiprazole
Abilify
Aripiprazole (Abilify) is a medicine used to treat certain mental disorders and mood problems.
Compare with entacapone →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for entacapone: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 3,955.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 15.25%.
- sildenafil Δ 0.08 pts · 55,325 reports · PDE5 Inhibitor 15.17%death share
- oseltamivir Δ 0.08 pts · 7,575 reports · Neuraminidase Inhibitor (Antiviral) 15.17%death share
- senna Δ 0.09 pts · 20,197 reports · Stimulant Laxative 15.34%death share
- memantine Δ 0.15 pts · 12,807 reports · NMDA Receptor Antagonist 15.10%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
Save on entacapone
Compare prices and find discounts at pharmacies near you. Free coupons can save up to 80% on prescriptions.
Disclosure: This link may earn us a commission at no extra cost to you. See our terms.
What the FDA Data Shows for entacapone
The FDA label for entacapone (sold under brand names such as Comtan) classifies it as a prescription-only medication in the COMT Inhibitor class. Entacapone is used to treat Parkinson's disease. Official labeling lists 8 commonly reported side effects, including Uncontrolled movements, Urine discoloration, Diarrhea.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 3,955 voluntary reports. The database also lists 3 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.32.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: October 7, 2023
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages