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Generic name: tolcapone [ TOLE-ka-pone ]
Brand name: Tasmar
Dosage form: oral tablet (100 mg)
Drug class: Dopaminergic antiparkinsonism agents

Medically reviewed by on Jan 1, 2024. Written by Cerner Multum.

What is tolcapone?

Tolcapone is used together with other medicines (carbidopa and levodopa) to treat symptoms of Parkinson's disease, such as stiffness, tremors, muscle spasms, and poor muscle control. Tolcapone increases levels of levodopa in the body.

Tolcapone is usually given to people who are already taking carbidopa and levodopa but have not had successful treatment of symptoms.

Tolcapone may also be used for purposes not listed in this medication guide.

Tolcapone side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

In rare cases, tolcapone can cause a condition that results in the breakdown of skeletal muscle tissue, leading to kidney failure. Call your doctor right away if you have unexplained muscle pain, tenderness, or weakness especially if you also have fever, unusual tiredness, or dark colored urine.

Also call your doctor at once if you have:

Certain side effects may be more likely in older adults.

You may have increased sexual urges, unusual urges to gamble, or other intense urges while taking tolcapone. Talk with your doctor if this occurs.

Common side effects of tolcapone may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


You should not use this medicine if you have liver disease, if you have ever had liver problems caused by tolcapone, or if you have ever had muscle damage or fever and confusion caused by using any medication.

Do not use tolcapone if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

Tolcapone can cause liver failure. Call your doctor at once if you have unusual tiredness, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes). Your liver function will need to be checked often.

Before taking this medicine

You should not use tolcapone if you are allergic to it, or if you have:

Do not use tolcapone if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

Tolcapone can cause liver failure. You may be required to read and sign a Patient Consent form before you get a prescription for tolcapone.

To make sure tolcapone is safe for you, tell your doctor if you have ever had:

People with Parkinson's disease may have a higher risk of skin cancer (melanoma). Talk to your doctor about this risk and what skin symptoms to watch for.

It is not known whether tolcapone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether tolcapone passes into breast milk or if it could affect the nursing baby. Tell your doctor if you are breast-feeding.

How should I take tolcapone?

Your doctor will perform blood tests to make sure you do not have conditions that would prevent you from safely using tolcapone.

Follow all directions on your prescription label. Your doctor may occasionally change your dose. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Do not take tolcapone as your only Parkinson's medication. Tolcapone must be used in combination with carbidopa and levodopa.

Tolcapone is usually taken three times a day. The first dose is taken with your first daily dose of carbidopa and levodopa. The second and third doses of tolcapone are taken 6 and 12 hours later.

Follow your doctor's dosing instructions very carefully.

Tolcapone may be taken with or without food.

Tolcapone may cause you to fall asleep during normal daytime activities such as working, talking, eating, or driving. You may fall asleep suddenly, even after feeling alert. Tell your doctor if you have any problems with daytime sleepiness or drowsiness.

Your liver function will need to be checked often: Every 2 to 4 weeks for the first 6 months of treatment, and then as often as your doctor recommends.

Call your doctor if your symptoms do not improve after 3 weeks of treatment.

Do not stop using tolcapone suddenly, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using tolcapone.

Store at room temperature in a tightly closed container, away from moisture and heat.

Tolcapone dosing information

Usual Adult Dose for Parkinson's Disease:

Initial dose: 100 mg orally 3 times a day
-Dose should be increased to 200 mg orally 3 times a day only if the anticipated incremental clinical benefit is justified
Maximum dose: 600 mg/day

-Because of the risk of potentially fatal acute fulminant liver failure, this drug should only be used in patients who are experiencing symptom fluctuations and are not responding satisfactorily to, or are not appropriate candidates for, other adjunctive therapies.
-For patients who do not demonstrate observable symptomatic benefit within 3 weeks of starting therapy, therapy should be discontinued.
-In clinical trials, the first dose of the day was always taken with the first dose of the day of levodopa/carbidopa, and subsequent doses were given 6 and 12 hours later.
-In clinical trials, a majority of patients who had levodopa doses greater than 600 mg/day or had moderate or severe dyskinesias prior to starting therapy, required a dose reduction of levodopa; the average dose reduction of levodopa was about 30%.

Use: As an adjunct to levodopa and carbidopa for the treatment of the signs and symptoms of idiopathic Parkinson's disease.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose can cause vomiting and severe dizziness.

What should I avoid while taking tolcapone?

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

Drinking alcohol with tolcapone can cause side effects.

What other drugs will affect tolcapone?

Taking tolcapone with other drugs that make you sleepy can worsen this effect. Ask your doctor before taking a sleeping pill, opioid pain medication, muscle relaxer, or medicine for anxiety, depression, or seizures.

Other drugs may interact with tolcapone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.