entacapone
Brand names: Comtan
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.
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 →
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.
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.
How to Take It
Take one 200 mg tablet with each dose of levodopa and carbidopa. Do not take it more than 8 times a day, for a total of 1600 mg of entacapone. You can take entacapone with or without food. Your doctor may need to lower your levodopa dose when you start taking entacapone, especially if you take a high dose of levodopa (800 mg or more).
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if entacapone will harm your unborn baby. Talk to your doctor about the risks and benefits of taking entacapone while breastfeeding.
Missed Dose
Take the missed dose with your next dose of levodopa and carbidopa. Do not take extra entacapone to make up for the missed dose.
Storage
Store entacapone at room temperature, between 68°F and 77°F.
Side Effects (from patient reports)
Based on 3,272 FDA adverse event reports.
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
Death-Related Reports
603
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 |
| 4 | DRUG INEFFECTIVE | 332 |
| 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 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) 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 entac...
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.
What to do: Use this combination with caution as directed by your doctor. Your healthcare provider may need to adjust your dose to prevent side effects.
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 interactio...
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.
What to do: Use this combination with extreme caution and at the lowest doses possible. Tell your doctor right away if you experience a severe headache, fast heartbeat, or sudden changes in your mood.
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.
What to do: Your doctor should monitor your blood clotting levels (INR) closely when you start entacapone or change your dose.
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?
Is entacapone safe during pregnancy?
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.
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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 3,272 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 further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
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. Always consult a healthcare professional before making medication decisions.
Last updated: October 7, 2023
Read our methodology — how this data is sourced, computed, and verified.
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