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Carbidopa and levodopa

Generic Name: carbidopa and levodopa (KAR bi DOE pa and LEE voe DOE pa)
Brand Name: Rytary, Sinemet, Sinemet CR

Medically reviewed by Drugs.com on Jun 23, 2020 – Written by Cerner Multum

What is carbidopa and levodopa?

Carbidopa and levodopa is a combination medicine used to treat symptoms of Parkinson's disease, such as muscle stiffness, tremors, spasms, and poor muscle control. Parkinson's disease may be caused by low levels of a chemical called dopamine (DOE pa meen) in the brain.

Carbidopa and levodopa is also used to treat Parkinson symptoms caused by carbon monoxide poisoning or manganese intoxication.

Carbidopa and levodopa may also be used for purposes not listed in this medication guide.

Important Information

You should not use carbidopa and levodopa if you have narrow-angle glaucoma.

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

Before taking this medicine

You should not use carbidopa and levodopa if you are allergic to it, or if you have:

  • narrow-angle glaucoma.

Do not use carbidopa and levodopa 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.

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.

Tell your doctor if you are pregnant or breastfeeding.

The disintegrating tablet may contain phenylalanine. Tell your doctor if you have phenylketonuria (PKU).

How should I take carbidopa and levodopa?

If you already take levodopa, you must stop taking it at least 12 hours before you start taking carbidopa and levodopa.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Carbidopa and levodopa can be taken with or without food. Take your doses at regular intervals to keep a steady amount of the drug in your body at all times. Get your prescription refilled before you run out of medicine completely.

Swallow the capsule whole and do not crush, chew, break, or open it.

The tablet is sometimes broken in half to give the correct dose. Always swallow a whole or half tablet without chewing or crushing.

Remove an orally disintegrating tablet from the package only when you are ready to take the medicine. Place the tablet in your mouth and allow it to dissolve, without chewing. Swallow several times as the tablet dissolves.

It may take up to several weeks of using carbidopa and levodopa before your symptoms improve. For best results, keep using the medication as directed. Talk with your doctor if your symptoms do not improve after a few weeks of treatment. Also tell your doctor if the effects of this medication seem to wear off quickly in between doses.

If you use carbidopa and levodopa long-term, you may need frequent medical tests at your doctor's office.

This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using carbidopa and levodopa.

Do not stop using carbidopa and levodopa suddenly, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using this medicine.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

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

What should I avoid while taking carbidopa and levodopa?

Avoid driving or hazardous activity until you know how carbidopa and levodopa will affect you. Your reactions could be impaired. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Avoid taking iron supplements or eating a diet that is high in protein (protein sources include meat, eggs, and cheese). These things can make it harder for your body to digest and absorb carbidopa and levodopa. Talk with your doctor or nutrition counselor about the best foods to eat while you are taking this medicine.

Carbidopa and levodopa side effects

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

Call your doctor at once if you have:

  • uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);

  • worsening of tremors (uncontrolled shaking);

  • severe or ongoing vomiting or diarrhea;

  • confusion, hallucinations, unusual changes in mood or behavior;

  • depression or suicidal thoughts; or

  • severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.

Some people taking carbidopa and levodopa have fallen asleep during normal daytime activities such as working, talking, eating, or driving. Tell your doctor if you have any problems with daytime sleepiness or drowsiness.

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

You may notice that your sweat, urine, or saliva appears dark in color, such as red, brown, or black. This is not a harmful side effect, but it may cause staining of your clothes or bed sheets.

Common side effects 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.

What other drugs will affect carbidopa and levodopa?

Other drugs may affect carbidopa and levodopa, 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.