Entacapone
Entacapone is a COMT-inhibitor tablet taken together with levodopa and carbidopa to treat end-of-dose “wearing-off” in people with Parkinson’s disease.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 14 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Entacapone is a common add-on to levodopa and carbidopa for Parkinson’s “wearing-off” (symptoms returning before the next dose is due). It has been on the market since about 1999 and is available generically. It blocks COMT, an enzyme that breaks down levodopa mostly outside the brain, so each dose lasts longer. It is generally well tolerated, but because it boosts levodopa it can bring more extra, uncontrolled movements (dyskinesia), and nausea, diarrhea and harmless brownish-orange urine are common. Watch for daytime sleepiness or falling asleep without warning, even a year in, and never stop it suddenly, since that can bring back symptoms with high fever, stiffness and confusion.
Clinical pearls
- Take it at the same moment as each levodopa/carbidopa dose, since on its own it has no effect on Parkinson’s symptoms.
- New jerky or writhing movements after starting often mean the levodopa dose needs trimming, not that entacapone must stop.
- Warfarin users need an INR blood check when entacapone starts or its dose goes up.
- Remind hospital teams you take it, since drugs like epinephrine, dopamine and dobutamine can raise heart rate or shift blood pressure.
Patient information guide A plain-language walkthrough of Entacapone, written from its FDA label.
What Entacapone is used for
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Entacapone is used as an add-on treatment for Parkinson’s disease.
- Entacapone tablets (oral) treat end-of-dose “wearing-off” in Parkinson’s disease, when taken with levodopa and carbidopa.
- It has not been well studied in people with Parkinson’s disease who do not have wearing-off.
How Entacapone works
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Entacapone blocks COMT, an enzyme that breaks down levodopa outside the brain. With less breakdown, levodopa levels in the blood are higher and last longer when taken with carbidopa.
This is believed to give steadier dopamine stimulation in the brain and better control of Parkinson’s symptoms. It can also increase levodopa side effects.
Entacapone dosage
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Entacapone tablets are taken by mouth together with each levodopa and carbidopa dose. They can be taken with or without food.
- It should always be given with levodopa and carbidopa, since it does not treat Parkinson’s on its own.
- Your prescriber may lower your levodopa dose or lengthen the time between doses.
- Don’t stop it suddenly. Follow your prescriber and the label.
Dosing details from the FDA-approved label
From the Entacapone prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Parkinson's disease patients (adjunct to levodopa and carbidopa)
- One 200 mg tablet administered concomitantly with each levodopa and carbidopa dose
- Maximum: 8 times daily (200 mg x 8 = 1,600 mg per day)
- May be taken with or without food; can be combined with immediate and sustained-release levodopa/carbidopa; levodopa dose reduction or longer dosing interval may be needed (average reduction about 25%)
- Patients with impaired hepatic function
- Treat with caution
- No specific dose given
- AUC and Cmax of entacapone approximately doubled in patients with documented liver disease (single-dose studies)
- Withdrawing patients from entacapone
- If discontinuing, withdraw slowly and monitor patients closely
- Adjust other dopaminergic treatments as needed
- Rapid withdrawal or abrupt dose reduction could cause signs and symptoms of Parkinson's disease, hyperpyrexia and confusion
Read the label’s full dosing text
DOSAGE AND ADMINISTRATION The recommended dose of entacapone tablets is one 200 mg tablet administered concomitantly with each levodopa and carbidopa dose to a maximum of 8 times daily (200 mg x 8 = 1,600 mg per day). Clinical experience with daily doses above 1,600 mg is limited. Entacapone tablets should always be administered in association with levodopa and carbidopa. Entacapone has no antiparkinsonian effect of its own. In clinical studies, the majority of patients required a decrease in daily levodopa dose if their daily dose of levodopa had been greater than or equal to 800 mg or if patients had moderate or severe dyskinesia before beginning treatment. To optimize an individual patient’s response, reductions in daily levodopa dose or extending the interval between doses may be necessary. In clinical studies, the average reduction in daily levodopa dose was about 25% in those patients requiring a levodopa dose reduction. (More than 58% of patients with levodopa doses above 800 mg daily required such a reduction.) Entacapone tablets can be combined with both the immediate and sustained-release formulations of levodopa and carbidopa. Entacapone tablets may be taken with or without food (see CLINICAL PHARMACOLOGY ). Patients With Impaired Hepatic Function : Patients with hepatic impairment should be treated with caution. The AUC and C max of entacapone approximately doubled in patients with documented liver disease, compared to controls. However, these studies were conducted with single-dose entacapone without levodopa and dopa decarboxylase inhibitor coadministration, and therefore the effects of liver disease on the kinetics of chronically administered entacapone have not been evaluated (see CLINICAL PHARMACOLOGY , Pharmacokinetics of Entacapone ). Withdrawing Patients from Entacapone tablets : Rapid withdrawal or abrupt reduction in the entacapone tablets dose could lead to emergence of signs and symptoms of Parkinson’s disease (see CLINICAL PHARMACOLOGY , Clinical Studies ), and may lead to hyperpyrexia and confusion, a symptom complex resembling NMS (see PRECAUTIONS , Other Events Reported With Dopaminergic Therapy ). This syndrome should be considered in the differential diagnosis for any patient who develops a high fever or severe rigidity.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Entacapone side effects
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The most common side effects seen in studies were:
Common side effects
- Dyskinesia (uncontrolled, extra movements)
- Hyperkinesia (excess movement)
- Nausea
- Diarrhea
- Urine discoloration (brownish-orange)
- Abdominal pain
- Vomiting
- Dry mouth
When to get medical help
- Call your doctor if you feel sleepy during the day or fall asleep suddenly during activities like eating or talking.
- Get help right away if you develop a high fever, severe muscle stiffness or confusion, especially after stopping or cutting back entacapone.
- Tell your doctor if you have a fast or irregular heartbeat or big swings in blood pressure, especially when using certain other medicines.
- Report ongoing severe diarrhea, nausea or abdominal pain.
- Hepatitis (liver inflammation) has been reported, so tell your doctor about symptoms of liver trouble.
Call your doctor about sudden sleep episodes, severe or ongoing diarrhea, high fever with stiffness or confusion, or signs of liver problems.
Entacapone warnings and precautions
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- Sudden sleepiness: People have fallen asleep without warning during daily activities, sometimes causing accidents.
- Stopping suddenly: This can bring back Parkinson’s symptoms and cause high fever and confusion.
- Heart effects with some drugs: Medicines broken down by COMT may cause faster heart rate, rhythm problems and blood pressure swings.
- Liver: Use caution with liver disease. Hepatitis has been reported.
Entacapone interactions
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Several medicines need caution with entacapone.
- Non-selective MAO inhibitors: should ordinarily not be combined, as they block many pathways for processing catecholamines.
- Selegiline (an MAO-B inhibitor): can be used together.
- COMT-metabolized drugs such as epinephrine, norepinephrine, dopamine, dobutamine, isoproterenol and apomorphine: may raise heart rate or change blood pressure.
- Warfarin: INR can rise, so monitoring is recommended.
- Probenecid, cholestyramine and some antibiotics: may interfere with how entacapone is cleared.
Interactions listed in the FDA-approved label
From the Entacapone prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Warfarin: AUC for R-warfarin increased on average by 18% and INR values increased on average by 13% in a healthy volunteer study; S-warfarin plasma levels not significantly changed; cases of significantly increased INR reported postapproval. Monitor INR when entacapone is initiated or when the dose is increased in patients receiving warfarin.
- CYP enzymes (1A2, 2A6, 2C9, 2C19, 2D6, 2E1, 3A): Entacapone inhibited these enzymes only at very high concentrations, so inhibition is not expected in clinical use.
- Highly protein-bound drugs (warfarin, salicylic acid, phenylbutazone, diazepam): In vitro studies showed no binding displacement between entacapone and these drugs.
- Non-selective MAO inhibitors: Label refers to WARNINGS regarding concomitant use. See WARNINGS.
- Selegiline (MAO-B inhibitor): No interaction noted in two multiple-dose studies with levodopa and dopa decarboxylase inhibitor; more than 600 patients used selegiline with entacapone and levodopa/DDC inhibitor.
- Drugs interfering with biliary excretion, glucuronidation, and intestinal beta-glucuronidase (probenecid, cholestyramine, some antibiotics such as erythromycin, rifampicin, ampicillin, chloramphenicol): Most entacapone excretion is via the bile, so these drugs may interfere. Exercise caution when given concurrently with entacapone.
- Imipramine (tricyclic antidepressant): No interaction shown in a single-dose study with entacapone without levodopa and dopa-decarboxylase inhibitor.
- Levodopa hormone effects (prolactin, growth hormone): Levodopa depresses prolactin secretion and increases growth hormone levels; entacapone with levodopa and dopa decarboxylase inhibitor does not change these effects.
- Drugs metabolized by catechol-O-methyltransferase (COMT): Label refers to WARNINGS. See WARNINGS.
Read the label’s full interactions text
Drug Interactions In vitro studies of human CYP enzymes showed that entacapone inhibited the CYP enzymes 1A2, 2A6, 2C9, 2C19, 2D6, 2E1 and 3A only at very high concentrations (IC50 from 200 microM to over 1,000 microM; an oral 200 mg dose achieves a highest level of approximately 5 microM in people); these enzymes would therefore not be expected to be inhibited in clinical use. 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. Protein Binding Entacapone is highly protein bound (98%). In vitro studies have shown no binding displacement between entacapone and other highly bound drugs, such as warfarin, salicylic acid, phenylbutazone, and diazepam. Drugs Metabolized by Catechol- O -Methyltransferase (COMT) See WARNINGS. Hormone Levels Levodopa is known to depress prolactin secretion and increase growth hormone levels. Treatment with entacapone coadministered with levodopa and dopa decarboxylase inhibitor does not change these effects. Effect of Entacapone on the Metabolism of Other Drugs See WARNINGS regarding concomitant use of entacapone and non-selective MAO inhibitors. No interaction was noted with the MAO-B inhibitor selegiline in two multiple-dose interaction studies when entacapone was coadministered with a levodopa and dopa decarboxylase inhibitor (n=29). More than 600 patients with Parkinson’s disease in clinical studies have used selegiline in combination with entacapone and levodopa and dopa decarboxylase inhibitor.
Excerpted — the section continues on the label. Read the full Drug Interactions section on DailyMed →
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Entacapone
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- Do not use if you are allergic to entacapone or its ingredients.
- Tell your doctor about liver disease or bile duct blockage.
- Mention sleep disorders and sedating medicines.
- Review all your medicines, especially warfarin and MAO inhibitors.
- Kidney impairment did not have important effects on entacapone levels in a study.
Entacapone overdose
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Overdose has caused sleepiness, reduced activity, confusion, coma, restlessness, agitation, aggression, and discoloration of skin, tongue and urine. There is no known antidote. Treatment is supportive care in a hospital, so get emergency help right away.
What Entacapone does in the body
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Entacapone reversibly inhibits COMT in red blood cells. The effect grows with dose, and at a single 200 mg dose it averaged about 65% maximum inhibition, returning to baseline within 8 hours.
How your body processes Entacapone
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Entacapone is absorbed quickly, with peak levels in about 1 hour, and food does not affect it. It is highly bound to proteins in blood and is almost completely metabolized. Most leaves through the bile into feces. With levodopa and carbidopa, it extends levodopa’s half-life from about 1.3 to 2.4 hours. Liver disease roughly doubled entacapone levels in a single-dose study.
How to store Entacapone
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Store at 20º to 25ºC (68º to 77ºF); excursions permitted to 15°C to 30°C (59°F to 86°F).
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Entacapone
33 supplements and herbal products have documented interactions with Entacapone in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 22
- Minor · 10
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Entacapone: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Entacapone — the kind of thing our pharmacy team would talk through with you at the counter.
What is entacapone for?
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How should I take it?
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What side effects should I expect?
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Is it safe to drive on entacapone?
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Can I take it with my other medicines?
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What happens if I stop it suddenly?
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Is Entacapone available over the counter?
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When was Entacapone first available?
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Who makes Entacapone?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Entacapone on HelloPharmacist
Entacapone forms and strengths (how it comes)
Entacapone is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Entacapone inactive ingredients by manufacturer.
Tablet
How this form is used
- Entacapone tablets are used with levodopa and carbidopa to treat end-of-dose “wearing-off” in Parkinson’s disease.
- Entacapone tablets are taken by mouth with each levodopa and carbidopa dose.
- Entacapone tablets may be taken with or without food.
- Entacapone tablets can be combined with immediate-release and sustained-release levodopa and carbidopa.
Entacapone on the U.S. market: products, makers and brands
How Entacapone appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
14 companies list 14 Entacapone product records with the FDA, mostly as tablet; the earliest marketing or approval year on record is 1999. Brand names on the directory include Comtan; the rest are generics.
Also listed with the FDA, not a patient dose form: Powder (11) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
How widely Entacapone is used (Medicaid data)
A general measure of how commonly Entacapone is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Entacapone is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Entacapone prescribed? Of the 1,601 medications we measure, Entacapone ranks #1,075 by Medicaid prescriptions — more than 33% of them.
Utilization by Entacapone product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
entacapone 200 MG Oral Tablet
Summed across the 4 of 39 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 317094
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Entacapone, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 4 of 39 listed Entacapone NDCs with Medicaid activity.
Compare Entacapone products
A representative set of FDA-listed product records for Entacapone — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 200 mg | Oral | Ajanta Pharma USA Inc. | ANDA | View NDC → |
| 200 mg | Oral | Alembic Pharmaceuticals Inc. | ANDA | View NDC → |
| 200 mg | Oral | Alembic Pharmaceuticals Limited | ANDA | View NDC → |
| 200 mg | Oral | American Health Packaging | ANDA | View NDC → |
| 200 mg | Oral | Aphena Pharma Solutions - Tennessee, LLC | NDA AUTHORIZED GENERIC | View NDC → |
| 200 mg | Oral | Aurobindo Pharma Limited | ANDA | View NDC → |
| 200 mg | Oral | AvPAK | ANDA | View NDC → |
| 200 mg | Oral | Lannett Company, Inc. | ANDA | View NDC → |
| 200 mg | Oral | Macleods Pharmaceuticals Limited | ANDA | View NDC → |
| 200 mg | Oral | Major Pharmaceuticals | ANDA | View NDC → |
| 200 mg | Oral | NCS HealthCare of KY, LLC dba Vangard Labs | ANDA | View NDC → |
| 200 mg | Oral | Rising Pharma Holdings, Inc. | ANDA | View NDC → |
| 200 mg | Oral | Sandoz Inc | NDA AUTHORIZED GENERIC | View NDC → |
| 200 mg | Oral | Sun Pharmaceutical Industries, Inc. | NDA AUTHORIZED GENERIC | View NDC → |
Showing 14 of 14 products — FDA National Drug Code Directory. See every product, package size and price: browse all 14 Entacapone NDCs →
Entacapone side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Entacapone — a signal of what to watch for, not proof the drug caused it.
The effects most often named in FDA reports that mention Entacapone are hallucination, fall, dyskinesia; about 71% of the reports were classed as serious. These are voluntary reports, so they show what people report, not how often it happens.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Entacapone in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Entacapone FDA approval history
How Entacapone went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Entacapone was first approved by the FDA in 1999 (Brand: COMTAN · Orion Pharma); the first generic version was approved in 2012. It remains available in U.S. pharmacies today.
Source: Drugs@FDA.
Entacapone recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list one Entacapone recall since July 2021. It is no longer listed as ongoing. A recall names specific lots from one company, so check the lot number on your own bottle rather than assuming every product is affected; your pharmacist can check whether your supply came from an affected lot.
- Entacapone Tablets, USP, 200 mg, Rx only, 30 Tablets per unit dose cartons, Distributed by: Major Pharmaceuticals, 17177 N. Laurel Park Dr., Suite 233, Livonia, MI 48152. NDC 0904-6822-04 Lots: Lot, expiry: N00187, 05/2022; N00245, 06/2022; N00273, 07/2022; N00355, 11/2022 FDA record D-0806-2021 →
Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 60307 1 dose form · 1 strength
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Dose form (SCDF) Oral Tablet RxCUI 374616In current FDA listingsClinical drug / strength (SCD) 200 MGRxCUI 317094
Look up RxCUI 60307 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Entacapone supply and shortage status
Whether Entacapone is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
💵 What Entacapone costs pharmacies (NADAC benchmark)
The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Sep 30, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.
| Form | Strength | Pharmacy acquisition benchmark | |
|---|---|---|---|
| Tablet, Film Coated · Oral | 200 mg | $0.325 per tablet | NDC details & price history |
Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.
Entacapone brand names
Entacapone is sold under one brand name in the FDA directory — Comtan. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Entacapone: manufacturers and labelers
14 companies list Entacapone products with the FDA. By number of product records, the largest are Ajanta Pharma USA Inc., Alembic Pharmaceuticals Inc., Alembic Pharmaceuticals Limited. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Entacapone drug class (RxNorm)
Entacapone belongs to the Catechol-O-Methyltransferase Inhibitor class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Entacapone page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Aphena Pharma Solutions - Tennessee, LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →