Carbidopa & Levodopa

Carbidopa/levodopa treats symptoms of Parkinson's disease.

Carbidopa & Levodopa Overview

Reviewed: January 12, 2015
Updated: 

Carbidopa/Levodopa is a prescription medication used to treat symptoms of Parkinson's disease. It can also treat Parkinson's-like symptoms caused by certain conditions and injuries to the central nervous system. Parkinson's symptoms, including tremors (shaking), stiffness, and slowness of movement, are caused by a lack of dopamine, a natural substance usually found in the brain.

It is a single product containing 2 medications: levodopa and carbidopa. Levodopa is in a class of medications called central nervous system agents. It is converted to dopamine in the brain. Carbidopa is in a class of medications called decarboxylase inhibitors. It works by preventing levodopa from being broken down before it reaches the brain.

This combination medication comes in regular tablet, orally disintegrating tablet, and extended-release (long-acting) tablet, extended-release capsule, and suspension forms to be taken by mouth. Carbidopa/levodopa is also available as an enteral suspension to be given through a tube placed in the stomach or intestines.  This medication is usually taken 3 to 4 times a day.

Common side effects include nausea and abnormal movements.

Carbidopa/levodopa can cause drowsiness, dizziness, and blurred vision. Do not drive or operate heavy machinery until you know how carbidopa/levodopa affects you.

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Uses of Carbidopa & Levodopa

Carbidopa/levodopa is a prescription medication used to treat symptoms of Parkinson's disease.

It is also used to treat Parkinson's-like symptoms that may develop after encephalitis (swelling of the brain) or injury to the nervous system caused by carbon monoxide poisoning or manganese poisoning.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Carbidopa & Levodopa Brand Names

Carbidopa & Levodopa may be found in some form under the following brand names:

Carbidopa & Levodopa Drug Class

Carbidopa & Levodopa is part of the drug class:

Side Effects of Carbidopa & Levodopa

Serious side effects have been reported with carbidopa/levodopa. See the "Carbidopa & Levodopa Precautions" section.

Common side effects of carbidopa/levodopa include the following:

  • dizziness
  • nausea
  • vomiting
  • loss of appetite
  • diarrhea
  • dry mouth
  • constipation
  • changes in sense of taste
  • forgetfulness or confusion
  • nervousness
  • nightmares
  • difficulty sleeping
  • headaches
  • weakness
  • increased sweating
  • drowsiness
  • abnormal or impaired movement

This is not a complete list of carbidopa/levodopa side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Carbidopa & Levodopa Interactions

Tell your doctor about all the medications you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

  • antidepressants such as amitriptyline (Elavil), amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Adapin, Sinequan), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil)
  • antihistamines
  • haloperidol (Haldol)
  • ipratropium (Atrovent)
  • iron pills and vitamins containing iron
  • isocarboxazid (Marplan)
  • isoniazid (INH, Nydrazid)
  • medications for high blood pressure, irritable bowel disease, mental illness, motion sickness, nausea, ulcers, or urinary problems
  • metoclopramide (Reglan)
  • papaverine (Pavabid)
  • phenytoin (Dilantin)
  • rasagiline (Azilect)
  • risperidone (Risperdal)
  • selegiline (Eldepryl)

This is not a complete list of carbidopa/levodopa drug interactions. Ask your doctor or pharmacist for more information.

Carbidopa & Levodopa Precautions

Serious side effects have been reported with carbidopa/levodopa.

  • unusual or uncontrolled movements of the mouth, tongue, face, head, neck, arms, and legs
  • fast, irregular, or pounding heartbeat
  • depression
  • thoughts of death or suicide
  • hallucinations
  • swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
  • hoarseness
  • difficulty swallowing or breathing
  • hives
  • black, tarry stools
  • red blood in stools
  • blood in vomit
  • vomit that looks like coffee grounds

Carbidopa/levodopa can cause drowsiness, dizziness, and blurred vision. Do not drive or operate heavy machinery until you know how carbidopa/levodopa affects you.

Do not take carbidopa/levodopa if you:

  • are allergic to carbidopa/levodopa or any of its ingredients
  • are taking or have recently stopped taking a monoamine oxidase inhibitor (MAOI)

Carbidopa & Levodopa Food Interactions

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of carbidopa/levodopa, there are no specific foods that you must exclude from your diet when receiving this medication.

However, tell your doctor if you plan on changing your diet to include foods that are high in protein, such as meat, poultry, and dairy products, since these foods can affect the way your body uses the mediction.

Inform MD

Before taking carbidopa/levodopa, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

  • are allergic to carbidopa/levodopa or to any of its ingredients
  • have or have had glaucoma
  • have or have had melanoma (skin cancer) or a skin growth that has not been diagnosed
  • have or have had hormone problems
  • have asthma or emphysema
  • have mental illess
  • have diabetes
  • have or have had ulcers
  • have had a heart attack
  • have an irregular heart beat
  • have blood vessel, heart, kidney, liver, or lung disease
  • are pregnant or breastfeeding
  • have phenylketonuria

Tell your doctor about all the medicines you take inclyding prescription and non-prescription medicines, vitamins, and herbal supplements.

Carbidopa & Levodopa and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X - are used to classify the possible risks to an unborn baby when medication is taken during pregnancy.

Carbidopa/levodopa falls into category C. In animal stidues, pregnancy animals were given this medication and had some babies born with problems. No well-controlled studies have bene done in humans. Therefore, this medication may be used if the potential benefits to the mother outweight the potential risks to the unborn child.

Carbidopa & Levodopa and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed.

Levodopa, one of the components of carbidopa/levodopa, has been detected in human breast milk. Caution should be exercised when carbidopa/levodopa is given to a nursing woman.

Carbidopa & Levodopa Usage

Take carbidopa/levodopa exactly as prescribed.

This combination medication comes in regular tablet, orally disintegrating tablet, and extended-release (long-acting) tablet, extended-release capsule, and suspension forms to be taken by mouth. It is usually taken 3 to 4 times a day.

Carbidopa/levodopa is also available as an enteral suspension to be given through a tube placed in the stomach or intestines. 

Do not chew, divide, or break carbidopa/levodopa extended-release tablets or capsules. Swallow these forms whole.

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of carbidopa/levodopa at the same time.

Carbidopa & Levodopa Dosage

Take this medication exactly as prescribed by your doctor. Follow the directions on yoru prescription label carefully.

The dose your doctor recommends may be based on the following:

  • the condition being treated
  • other medical conditions you have
  • other medications you are taking
  • how you respond to this medication

The recommended starting dose of carbidopa/levodopa is 25 mg carbidopa/100 mg levodopa 3 times a day. The dose should be increased until symptom control is achieved.

Carbidopa & Levodopa Overdose

If you take too much carbidopa/levodopa, call your healthcare provider or local Poison Control Center or seek emergency medical attention right away.

If carbidopa/levodopa is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if an overdose is suspected, seek emergency medical attention.

Other Requirements

  • Store carbidopa/levodopa at room temperature.
  • Keep this and all medications out of the reach of children.