Carbidopa-Levodopa-Entacapone

Carbidopa-levodopa-entacapone is a prescription combination medication used to treat Parkinson’s disease. This guide explains the basics in plain language. It does not replace advice from your care team.

What is Carbidopa-Levodopa-Entacapone?

Carbidopa-levodopa-entacapone is a three-in-one prescription tablet. Each ingredient plays a different role:

• Levodopa is a dopamine precursor. The body converts it to dopamine in the brain.
• Carbidopa is a decarboxylase inhibitor. It helps more levodopa reach the brain.
• Entacapone is a catechol-O-methyltransferase (COMT) inhibitor. It slows the breakdown of levodopa so it lasts longer.

Approved use in the United States:

• Treating adults with Parkinson’s disease, either to replace carbidopa-levodopa and entacapone taken as separate tablets in people who are stable on them, or to replace carbidopa-levodopa in people who have “wearing-off” episodes and whose symptoms are not well controlled on carbidopa-levodopa alone (in some cases, only after a trial of the separate medicines)

Available formulations and strengths:

• Fixed-dose oral tablets, taken by mouth, in several strengths of carbidopa/levodopa/entacapone, including Carbidopa-Levodopa-Entacapone 50mg (12.5mg-, Carbidopa-Levodopa-Entacapone 100mg (25mg-, Carbidopa-Levodopa-Entacapone 150mg (37.5mg-

Each tablet contains 200 mg of entacapone. Strength names differ by brand, and the combination tablet is not interchangeable with carbidopa-levodopa alone or with entacapone alone without direction from your prescriber. Each strength has its own detailed page with more information.

What is the Recommended Dosage of Carbidopa-Levodopa-Entacapone?

There is no single dose that fits everyone. Your prescriber chooses the strength and schedule based on:

• Your current levodopa dose. Most people are matched to a tablet strength based on what they already take.
• Stage and severity of Parkinson’s disease. Needs often change over time.
• Symptom pattern. People with “wearing-off” or involuntary movements (dyskinesia) may need adjusted timing.
• Liver function. Entacapone is processed by the liver, so people with liver problems may need closer monitoring or a different plan.
• Age. Older adults may be more sensitive to side effects such as confusion and dizziness.
• Other medicines. Some drugs can change how the combination works.

Because each tablet has a fixed amount of entacapone, the number of tablets per day is usually limited, and the levodopa dose may need to be lowered when starting. Tablets are usually swallowed whole, one at a time, and are not split. Kidney function does not usually require a dose change. This medication has not been established for use in children. Always follow the exact instructions from your neurologist or other prescribing specialist and your pharmacy label. Do not change your dose or schedule on your own.

How Carbidopa-Levodopa-Entacapone Works

In Parkinson’s disease, brain cells that make dopamine are lost, which can lead to stiffness, tremor, and slow movement. Dopamine itself cannot enter the brain from the bloodstream, but levodopa can. Once in the brain, levodopa is converted into dopamine.

Carbidopa blocks one enzyme that breaks down levodopa outside the brain. Entacapone blocks a second enzyme, COMT, that also breaks down levodopa. Together, they allow levodopa to stay in the body longer, which may reduce “off” time between doses.

This medication helps manage symptoms. It does not cure Parkinson’s disease and has not been shown to slow its progression.

Is a Prescription Required to Buy Carbidopa-Levodopa-Entacapone Online?

Yes. In the United States, carbidopa-levodopa-entacapone is a prescription-only medication. A licensed clinician must decide whether it is appropriate for you. This is usually a neurologist, ideally one who specializes in movement disorders.

If you buy medication online, use only licensed, verified pharmacies that require a valid prescription. Be cautious of websites that offer prescription medicines without one. Counterfeit or improperly stored products may contain the wrong ingredient or the wrong amount. Products from unknown sources or made for animals are not safe substitutes.

Side Effects of Carbidopa-Levodopa-Entacapone

Common Side Effects

Many people have mild effects, especially early in treatment. These may include:

• Involuntary movements (dyskinesia), which may increase at first
• Nausea
• Diarrhea
• Abdominal pain
• Dizziness or lightheadedness
• Fatigue or drowsiness
• Constipation or dry mouth
• Vivid dreams or trouble sleeping
• Harmless brownish-orange discoloration of urine, and sometimes sweat or saliva

Tell your clinician if these effects continue or bother you. The levodopa dose may need adjusting.

Serious Side Effects

These are less common but need prompt attention:

• Hallucinations, confusion, or new paranoia
• Fainting or severe dizziness when standing up
• Severe or persistent diarrhea, which may appear weeks or months after starting
• Sudden episodes of falling asleep during daily activities
• New or unusual urges, such as gambling, binge eating, shopping, or increased sexual urges
• Signs of liver problems, such as yellowing of the skin or eyes or severe stomach pain
• Worsening depression, mood changes, or thoughts of self-harm
• Irregular or rapid heartbeat
• Black or bloody stools, or vomiting blood
• Fever, severe muscle stiffness, and confusion, especially after stopping the medicine suddenly
• Severe or worsening involuntary movements
• Tingling or numbness in the hands or feet
• Vision changes or eye pain

Seek emergency medical care for fainting, chest pain, trouble breathing, signs of an allergic reaction such as facial swelling or hives, or thoughts of self-harm.

Drug Interactions

Some medications and substances can raise the risk of side effects or change how this combination works. Examples include:

• Non-selective MAO inhibitors, such as phenelzine and tranylcypromine, which should not be used with this medication
• Selegiline and rasagiline (MAO-B inhibitors), which may be used together under close supervision, with dose limits for selegiline
• Medicines broken down by the same enzymes as entacapone, such as apomorphine, isoproterenol, epinephrine, norepinephrine, dopamine, dobutamine, and methyldopa, which may cause faster heart rate or blood pressure changes
• Iron supplements, which can reduce levodopa absorption and bind to entacapone in the gut
• Dopamine-blocking medicines, such as many antipsychotics, metoclopramide, and some anti-nausea medicines, which may reduce its effect
• Certain other medicines that lower dopamine, such as phenytoin, papaverine, and isoniazid
• Blood pressure medicines, which may add to low blood pressure or dizziness
• Sedating medicines, including sleep aids, sedatives, and alcohol, which may increase drowsiness
• Other Parkinson’s medicines, such as dopamine agonists and amantadine, which are often used together but may need dose changes

Over-the-counter products to review with a pharmacist include iron-containing vitamins, cough and cold products, decongestants, antihistamines, and sleep aids. Supplements and herbal products should also be reviewed, especially iron, vitamin B6 in high amounts, and products that cause drowsiness.

Give your licensed medical specialist a complete list of everything you take, including prescriptions, OTC medicines, vitamins, and herbal products.

Safety & Important Considerations

• Sleep attacks: Sudden sleepiness has been reported, including while driving. Talk with your clinician about safe driving and about activities that require alertness.
• Low blood pressure: Standing up slowly may help reduce dizziness.
• Impulse control problems: Compulsive gambling, eating, shopping, or sexual behavior can occur. Family members and caregivers may notice these changes first.
• Diarrhea: Persistent diarrhea, sometimes with weight loss, has been reported. Tell your clinician if it does not go away.
• Liver disease: Entacapone is processed by the liver. Use carefully and with monitoring. Rare liver injury has been reported with a related medicine (tolcapone), so tell your clinician about any liver history.
• Kidney disease: Dose changes are usually not needed, but monitoring may still be advised.
• Pregnancy: Human data are limited, and animal studies have shown harm with levodopa. Talk with your clinician before taking this medication if you are pregnant or planning pregnancy.
• Breastfeeding: Levodopa passes into breast milk and may lower milk production. Your clinician can help you weigh the options.
• Children: Safety and effectiveness have not been established.
• Older adults: Confusion, hallucinations, dizziness, and falls may be more likely, so closer monitoring is often needed.
• Other conditions: Tell your clinician if you have heart disease, irregular heartbeat, a history of stomach ulcers, glaucoma, psychiatric illness, or a history of compulsive behaviors.
• Do not stop suddenly. Abrupt discontinuation or a large dose reduction may cause a serious reaction with high fever, muscle stiffness, and confusion. Your clinician will guide any changes.
• Skin checks: Some studies have raised questions about a possible link between Parkinson’s disease or its treatments and skin cancer (melanoma). Regular skin checks are often recommended.
• Monitoring: Your clinician may check movement symptoms, blood pressure, mood, thinking, behavior, weight, and, in some cases, blood counts, liver and kidney tests, or vitamin B12 levels over time.

Who This Medication Is For

Carbidopa-levodopa-entacapone may be prescribed to adults with Parkinson’s disease who already take carbidopa-levodopa and entacapone separately and are stable on them, or who experience “wearing-off” symptoms on carbidopa-levodopa. It is not a first-line treatment for early Parkinson’s disease. It is also not used for other forms of parkinsonism unless a specialist advises it. Your specialist decides if it is suitable based on your health history, symptoms, and other treatments.

Who Should Not Take Carbidopa-Levodopa-Entacapone

This medication should not be used by:

• People who are allergic to carbidopa, levodopa, entacapone, or any ingredient in the product
• People taking non-selective MAO inhibitors, or who have taken one within the last 2 weeks
• People with narrow-angle glaucoma, in most cases
• People with suspicious, undiagnosed skin lesions or a history of melanoma, unless a specialist advises otherwise

Use with extra caution, and only with clinician guidance, if you have liver disease, heart disease, low blood pressure, severe dyskinesia, psychosis or other mental health conditions, a history of stomach ulcers, seizures, a history of neuroleptic malignant syndrome, or a history of compulsive behaviors. Use is also a concern if you are pregnant or breastfeeding, or if you are an older adult.

What to Do If You Miss a Dose

• Take the missed dose as soon as you remember, unless it is almost time for your next dose.
• If it is nearly time for the next dose, skip the missed one and return to your regular schedule.
• Never take a double dose to make up for a missed one.
• Missed doses can cause symptoms to return quickly, so contact your licensed medical specialist or pharmacist if you are unsure what to do or if you miss several doses in a row.

Related medications to Carbidopa-Levodopa-Entacapone

Other medicines may be used depending on the situation:

• Carbidopa-levodopa taken with separate entacapone tablets: allows the two medicines to be adjusted individually
• Carbidopa-levodopa alone: immediate-release, extended-release, or orally disintegrating forms
• Other COMT inhibitors: opicapone and tolcapone (tolcapone requires special liver monitoring), usually added to carbidopa-levodopa
• MAO-B inhibitors: rasagiline, selegiline, safinamide
• Dopamine agonists: pramipexole, ropinirole, rotigotine
• Others: amantadine, anticholinergic medicines, and apomorphine for “off” episodes
• Procedures: deep brain stimulation may be considered for some people with advanced disease

Each option has its own benefits and risks. Never switch or stop treatment without consulting your specialist.

Storage Instructions

• Store at room temperature, about 68°F to 77°F (20°C to 25°C), unless the label says otherwise.
• Keep in a tightly closed container, away from moisture, heat, and direct light. Avoid storing in a bathroom.
• Keep all medicines out of reach and sight of children and pets.
• Dispose of expired or unused medicine through a pharmacy take-back program when possible.

Disclaimer:

This page is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Patients must consult a licensed neurologist (or other relevant medical specialist, depending on the condition being treated) before starting, changing, or stopping treatment. Treatment decisions must be based on a full clinical evaluation by a qualified specialist.