Sinemet (carbidopa/levodopa) is a prescription drug that’s used to treat Parkinson’s disease and parkinsonism. The drug comes as a tablet that you swallow. Two tablets are usually taken four times per day for a total of eight tablets.

If you have Parkinson’s disease or parkinsonism from certain causes, your doctor might suggest Sinemet as a treatment option for you. It’s a prescription drug that treats adults with:

Sinemet contains the active ingredients carbidopa and levodopa. (An active ingredient is what makes a drug work.)

Carbidopa belongs to a group of drugs called decarboxylase inhibitors. And levodopa belongs to a group of drugs called dopamine precursors. They work together to increase dopamine levels in the brain.

Sinemet comes as a tablet that you swallow.

This article describes the dosages of Sinemet, as well as its strengths and how to take it. To learn more about Sinemet, see this in-depth article.

Note: This article covers Sinemet’s usual dosages that the drugmaker provides. But, when using Sinemet, always take the dosage your doctor prescribes.

The information listed below describes the usual dosages of Sinemet. Tablet strengths are listed in milligrams (mg), with the strength of carbidopa first and levodopa second (carbidopa/levodopa).

Note: This chart highlights the basics of Sinemet’s dosage if you’re new to Sinemet and its ingredients. If you’re switching to Sinemet from another drug containing levodopa, your starting dosage may differ. See “What are the usual dosages of Sinemet?” below for more information.

Starting dosageMaintenance dosage†Maximum dosage
Sinemet doseone tablet of either:

• 10 mg/100 mg
• 125 mg/100 mg*
two tablets in one of the following strengths:

• 110 mg/100 mg
• 125 mg/100 mg
• 125 mg/250 mg
two tablets of 25 mg/250 mg
How often you’ll take itthree or four times per dayfour times per dayfour times per day

* This is the typical starting dose. If your doctor prescribes this dose, you will usually take it only three times per day at first.
† Your maintenance dosage will depend on how your body responds to the medication. If the starting dosage isn’t effective for your condition, your doctor will slowly increase your dosage to find one that works for you.

What is Sinemet’s form?

Sinemet comes as a tablet that you swallow.

What strengths does Sinemet come in?

Each Sinemet tablet contains two active ingredients,* carbidopa and levodopa. The tablets are available in several strengths:

  • Sinemet 10 mg/100mg contains 10 mg of carbidopa and 100 mg of levodopa
  • Sinemet 25 mg/100 mg contains 25 mg of carbidopa and 100 mg of levodopa
  • Sinemet 25 mg/250 mg contains 25 mg of carbidopa and 250 mg of levodopa

* An active ingredient is what makes a drug work.

What are the usual dosages of Sinemet?

If you’ve never taken Sinemet before, your doctor will typically prescribe the standard starting dose of Sinemet. If you’re switching from another medication containing levodopa, your doctor will calculate your Sinemet dose based on the amount of levodopa you were taking before.

Your doctor will adjust your dosage over time to reach the right amount for you. They’ll ultimately prescribe the smallest dosage that provides the desired effect.

The information below describes dosages that are commonly used or recommended. But be sure to take the dosage your doctor prescribes for you. They’ll determine the best dosage to fit your needs.

Dosage for Parkinson’s disease and parkinsonism

Your starting dosage of Sinemet for Parkinson’s disease and parkinsonism will depend on if you’re new to levodopa treatment or if you’ve taken levodopa before.

If you’re new to levodopa treatment: The usual starting dose of Sinemet is one 25 mg/100 mg-strength tablet taken three times per day. In some cases, your doctor may prescribe a lower starting dose of one 10 mg/100 mg-strength tablet taken three or four times per day.

If you’ve taken levodopa before: Your doctor will calculate your Sinemet dosage based on your previous dosage of levodopa. The new dosage of the levodopa ingredient in Sinemet will usually be about 25% of your prior levodopa dosage. Your doctor will also have you stop taking your other levodopa medication at least 12 hours before you start taking Sinemet.

Typically, your doctor will calculate your new dosage in this way:

  • If your previous levodopa dose was less than 1500 mg, you’ll take one 25 mg/100 mg-strength tablet three or four times per day.
  • If your prior levodopa dose was more than 1500 mg, you’ll take one 25 mg/250 mg-strength tablet three or four times per day.

Maintenance and maximum dosages

Your doctor will slowly increase your dosage as needed until you’re taking two tablets four times per day (for a total of eight tablets per day). Depending on your symptoms, your doctor may divide these doses differently so that you take Sinemet five times per day.

Your maintenance dosage of Sinemet will depend on how your body responds to treatment. Your dosage will usually include at least 70 mg to 100 mg of the carbidopa ingredient per day. Your doctor will monitor you closely and adjust your dosage to prescribe the best dosage to manage your symptoms.

The maximum dose of Sinemet is eight 25 mg/250-mg strength tablets.

If you have questions about Sinemet’s dosages, talk with your doctor.

Is Sinemet used long term?

Yes, Sinemet is usually used as a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take it long term.

Below are answers to some commonly asked questions about Sinemet’s dosage.

What is the maximum dose of Sinemet?

The typical maximum daily dose of Sinemet is 200 milligrams (mg) of carbidopa and 2000 mg of levodopa, or eight 25 mg/250-mg strength tablets. It’s unknown whether it’s safe to take more than 200 mg of carbidopa per day.

Do I have to take my Sinemet doses at a certain dosing interval?

Yes. Your doctor will give you instructions on the dosing timing. When you begin treatment with Sinemet, your doctor will typically have you take one tablet three or four times per day.

In some cases, your doctor may change your dosing schedule so that you take Sinemet five times per day instead of four. Sometimes this is necessary to make sure you always have enough of the drug in your body for it to work effectively.

How does the dosage of Sinemet compare with the dosage of Sinemet CR?

Sinemet is an immediate-release version of carbidopa/levodopa, and Sinemet CR was an extended-release version. Sinemet releases its ingredients into the body within 30 minutes. But with extended-release drugs, the ingredients are slowly released into your body over a longer period of time.

Sinemet CR is no longer available, but the generic version (carbidopa/levodopa ER) is.

If you have questions about taking an extended-release drug for your condition, talk with your doctor. They can provide more details, including any differences in dosage.

If you miss a dose of Sinemet, talk with your doctor or pharmacist. They’ll be able to suggest whether you should skip the missed dose or if you need to take it.

If you need help remembering to take your dose of Sinemet on time, try using a medication reminder. This can include setting an alarm or downloading a reminder app on your phone.

The dosage of Sinemet your doctor prescribes may depend on several factors. These include:

  • the type and severity of the condition you’re using the drug to treat
  • other medications you may take
  • your overall health

Sinemet comes as a tablet that you swallow.

You can take Sinemet with or without food. But taking Sinemet with high protein foods (such as eggs or chicken) can cause your body to absorb less Sinemet. It can also make your body absorb the drug more slowly.

In general, it’s recommended that if you eat any high protein foods, you do so at least 30 minutes before or 60 minutes after taking Sinemet. To learn more, talk with your doctor about high protein foods and Sinemet.

If you have trouble swallowing tablets, see this article for tips that may help. And for information on the expiration, storage, and disposal of Sinemet, see this article.

Accessible drug containers and labels

If you find it hard to read the prescription label on your medication, tell your doctor or pharmacist. Some pharmacies provide medication labels that:

  • have large print or use braille
  • feature a code you can scan with a smartphone to change the text to audio

Your doctor or pharmacist may be able to recommend pharmacies that offer these accessibility features if your current pharmacy doesn’t.

If you have trouble opening medication bottles, let your pharmacist know. They may be able to supply Sinemet in an easy-open container. They may also have tips to help make it simpler to open the drug’s container.

Do not take more Sinemet than your doctor prescribes, as this can lead to serious side effects.

Symptoms of overdose

An overdose of Sinemet can cause dangerous changes in the rate or rhythm of your heart.

What to do in case you take too much Sinemet

Call your doctor right away if you think you’ve taken too much Sinemet. You can also call 800-222-1222 to reach the America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.

You should not suddenly stop taking Sinemet. Over time, your body can become dependent on the increased dopamine levels in your brain.

Suddenly stopping or lowering your dose of Sinemet can increase your risk of withdrawal symptoms. (Withdrawal symptoms are side effects that can occur when you stop taking a drug that your body has become dependent on.)

Sinemet withdrawal symptoms can be life threatening and cause symptoms similar to neuroleptic malignant syndrome. Symptoms can include:

If you want to change your Sinemet dosage or stop treatment, it’s important to talk with your doctor first.

The sections above describe the usual dosages provided by the drugmaker. If your doctor recommends Sinemet for you, they’ll prescribe the dosage that’s right for you.

Remember, you should not change your dosage of Sinemet without your doctor’s recommendation. Only take Sinemet exactly as prescribed. Talk with your doctor if you have questions or concerns about your current dosage.

Here are some examples of questions you may want to ask your doctor:

  • Does my dosage of Sinemet depend on my age?
  • Would I need a lower dose of Sinemet if I’m experiencing side effects?
  • Will I need a higher dose of Sinemet if I’m taking certain other medications?

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.