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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Limited Use [what does this mean?]
Generic drug name: entacapone (in TACK a pohn)
Brand name(s): COMTAN
GENERIC: not available FAMILY: Drugs for Parkinson’s Disease
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: entacapone with levodopa and carbidopa
Brand name(s): STALEVO
GENERIC: not available FAMILY: Drugs for Parkinson’s Disease
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

These drugs caused fetal harm in animal studies, including abortions, resorptions and decreased fetal weights, as well as malformed eyes, viscera, and skeleton. Because of the potential for serious adverse effects to the fetus, these drugs should not be used by pregnant women.

Breast-feeding Warning

These drugs are excreted in animal milk. It is likely that these drugs, like many others, are also excreted in human milk. Because of the potential for serious adverse effects in nursing infants, you should not take these drugs while nursing.

Facts About This Drug [top]

Entacapone (COMTAN) was approved by the Food and Drug Administration (FDA) in October 1999 to be used along with the combination drug levodopa and carbidopa (SINEMET, SINEMET CR) to treat Parkinson’s disease in patients who experience the signs and symptoms of end-of-dose “wearing off” of SINEMET. Entacapone’s effectiveness has not been systematically evaluated in patients with Parkinson’s disease who do not experience end-of-dose “wearing off.”[1]

The Medical Letter found entacapone to be...

Entacapone (COMTAN) was approved by the Food and Drug Administration (FDA) in October 1999 to be used along with the combination drug levodopa and carbidopa (SINEMET, SINEMET CR) to treat Parkinson’s disease in patients who experience the signs and symptoms of end-of-dose “wearing off” of SINEMET. Entacapone’s effectiveness has not been systematically evaluated in patients with Parkinson’s disease who do not experience end-of-dose “wearing off.”[1]

The Medical Letter found entacapone to be “modestly effective in prolonging the effectiveness of levodopa in Parkinson’s disease patients with ‘wearing-off’ motor fluctuations.”[2]

How it works

Entacapone is not used alone — it is used to improve the body's response to the drug combination levodopa and carbidopa, which are first-line drugs for treating parkinsonism.

Entacapone inhibits the enzyme COMT (catechol-O-methyltransferase), which breaks down levodopa, allowing the drug to stay in the body — especially in the brain — longer, preventing it from wearing off.[3],[4],[5] Thus entacapone improves mobility, balance and the ability to perform daily activities.[6],[7],[8]

When people with Parkinson's disease take levodopa, it replenishes dopamine and controls involuntary movements. However, after a few years, the levodopa becomes less effective, leading to imbalance and gait-freeze.[9],[3],[10] Changes in the dose of levodopa or the interval between doses alone may improve control. If the problem persists, then several other measures may be considered to improve control of Parkinson's symptoms and prevent the effects of levodopa from wearing off. These measures include other drugs, physical therapy and surgery.

Adverse effects

Since entacapone increases levodopa levels, it can cause more adverse effects of levodopa. These include involuntary movements, nausea and hallucination.

Although entacapone can help improve muscle control, it can damage muscles and cause involuntary movement of muscles that seem contorted. It also can cause repetitive movements of face, tongue, arms or legs. Furthermore, a sudden drop in blood pressure may occur when changing position.[1]

Another issue is that the European Medicines Agency, an agency similar to the FDA, has received multiple reports of liver disorders associated with the use of entacapone. An article published in Prescrire International concluded the following: “In practice, the risk of hepatic toxicity linked to entacapone is becoming clearer. This drug is not sufficiently effective to justify exposing patients to the risk of liver damage.”

Studies say...

In May 2004, a Medical Letter review of STALEVO expressed concern about the ease of use of this fixed-dose combination of three drugs (carbidopa, levodopa and entacapone):

Because of the fixed dose of entacapone, only one Stalevo tablet can be taken at each dosing interval. Stalevo tablets (which are not scored) should not be cut in half; doing so would reduce the dose of entacapone by half, which may be ineffective. Patients requiring more than 150 mg of levodopa per dose would have to take an additional carbidopa/levodopa pill. Those who are on different doses of levodopa throughout the day may require different Stalevo prescriptions for each one. This might cause more confusion because Stalevo pills, although shaped differently, are all the same color. Finally, patients who take controlled-release levodopa preparations (which are only 70% as bioavailable as immediate-release) plus entacapone cannot easily be switched to Stalevo.[11]

Regulatory actions surrounding entacapone

2009: The patient package insert for entacapone has been updated to include information on reports of an intense urge to gamble, increased sexual urges and other intense urges (and the inability to control these urges) in patients using it. In some cases the urges were stopped when the drug was decreased or stopped. However, it has not been proven that the drug caused these events.[12]

In August 2010, the FDA issued a safety warning to the public that it was conducting an ongoing review concerning the use of Stalevo. The FDA stated that it was evaluating information from a clinical trial that may show an increased risk of cardiovascular events (heart attack, stroke and cardiovascular death) associated with Stalevo compared with SINEMET (carbidopa and levodopa).[13]

2015: The FDA announced that the safety review initiated in 2010 had found no clear evidence of an increased risk of heart attacks, strokes or other cardiovascular events associated with the use of entacapone for the treatment of Parkinson’s disease.[14]

Before You Use This Drug [top]

Do not use if you have or have had:

  • allergy to entacapone

Tell your doctor if you have or have had:

  • low blood pressure
  • fainting spells
  • involuntary movements
  • liver problems
  • pregnancy or are breast-feeding

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Have regular visits to your doctor to monitor progress.
  • Do not drive or operate equipment requiring alertness until you know whether or not you develop dizziness, drowsiness, hallucinations, involuntary muscle movements, or change in blood pressure.
  • Change positions gradually when going from lying down to sitting, or sitting to standing.
  • Tell any doctor, dentist, emergency help, pharmacist, or surgeon you see that you use entacapone.
  • Always take this drug with levodopa/carbidopa; never take it by itself.
  • Check with your doctor before discontinuing this drug; gradual dosage reduction may be needed.
  • Drug may cause urine to turn brownish-orange. There is no need to contact your doctor if this happens.

How to Use This Drug [top]

  • Take at the same times of day that you take levodopa/carbidopa. Take with or without food, but be consistent.
  • If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day.
  • Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

ALDOMET, amitriptyline, amoxapine, ANAFRANIL, apomorphine, AVENTYL, clomipramine, desipramine, dobutamine, DOBUTREX, dopamine, doxepin, EFFEXOR, ELAVIL, ELDEPRYL, furazolidone, hypericum, imipramine, iron supplements, isocarboxazid, isoproterenol, ISUPREL, LEVOPHED, LUDIOMIL, maprotiline, MARPLAN, MATULANE, methyldopa, moclobemide, NARDIL, norepinephrine, NORPRAMIN, nortriptyline, pargyline, PARNATE, phenelzine, procarbazine, protriptyline, selegiline, SINEQUAN, SURMONTIL, TOFRANIL, tranylcypromine, trimipramine, venlafaxine, VIVACTIL.

Adverse Effects [top]

06Call your doctor immediately if you experience:

  • twitching
  • twisting
  • uncontrolled repetitive movements of tongue, lips, face, arms, or legs
  • hallucinations
  • hyperactivity
  • increase in body movements
  • absence of or decrease in body movements
  • fever
  • chills
  • cough or hoarseness
  • lower back or side pain
  • painful or difficult urination
  • confusion
  • shortness of breath
  • muscle cramps
  • pain
  • stiffness
  • weakness
  • unusual tiredness

Call your doctor if these symptoms continue:

  • abdominal pain
  • small red spots on skin
  • bruising
  • sleepiness or unusual drowsiness
  • increased sweating
  • acid or sour stomach
  • anxiety
  • back pain
  • belching
  • burning feeling in chest or stomach
  • constipation
  • diarrhea
  • difficult or labored breathing
  • dizziness
  • dry mouth
  • fatigue
  • heartburn
  • indigestion
  • irritability
  • loss of strength or energy
  • muscle pain or weakness
  • nausea
  • nervousness
  • passing gas
  • restlessness
  • shortness of breath
  • stomach discomfort, upset, or pain
  • tenderness in stomach area
  • tightness in chest
  • tremor
  • unusual weak feeling
  • vomiting
  • wheezing
  • unusual or unpleasant taste in mouth

last reviewed June 30, 2021