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carbidopa and levodopa enteral

Generic Name: carbidopa and levodopa enteral (Duopa) (KAR bi doe pa and LEE voe doe pa)
Brand Name: Duopa

What is carbidopa and levodopa?

Levodopa is converted to dopamine in the brain. Carbidopa helps prevent the breakdown of levodopa before it can reach the brain and take effect.

Carbidopa and levodopa enteral (Duopa) is a combination medicine used to treat movement problems in people with advanced Parkinson's disease. Duopa reduces the "off time" effect associated with taking other medicines to treat Parkinson's symptoms.

Duopa is a gel form of carbidopa and levodopa that is infused directly into the small intestine. This medicine is given with an infusion pump through a tube inserted into the wall of your stomach through a surgical incision called a "stoma" or a "port."

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

What is the most important information I should know about carbidopa and levodopa?

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.

What should I discuss with my healthcare provider before taking carbidopa and levodopa?

You should not use this medicine if you are allergic to carbidopa or levodopa.

Do not use Duopa 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.

To make sure Duopa is safe for you, tell your doctor if you have:

  • a stomach ulcer or a history of stomach surgery;

  • low blood pressure, or a history of fainting spells;

  • narcolepsy or a history of falling asleep during the daytime;

  • a muscle disorder such as myasthenia gravis;

  • nerve problems that cause numbness or tingling in your hands or feet;

  • a history of depression, mental illness, or psychosis;

  • glaucoma; or

  • heart disease, high blood pressure, heart rhythm disorder.

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 this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Duopa can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Duopa is not approved for use by anyone younger than 18 years old.

How should I take carbidopa and levodopa?

Follow all directions on your prescription label. Your doctor will occasionally change your dose to make sure you get the best results. Do not use this medicine in larger or smaller amounts or for longer than recommended.

You will need a surgical procedure to create your stoma. A special tube called a "PEG-J" tube, will be placed through the stoma and into your small intestine. This tube is attached to an infusion pump that will deliver Duopa into your body.

Duopa comes in a plastic cassette that is attached to the infusion pump. Your care provider will program the pump and show you how to use it. Read all patient information, medication guides, and instruction sheets provided to you. Ask your doctor or pharmacist if you have any questions.

Duopa is infused over a 16-hour period to help keep a steady amount of the drug in your body at all times. The infusion pump also allows extra doses if needed to reduce "off time" symptoms.

After the 16 hours, you may disconnect the pump and take a night-time dose of oral carbidopa and levodopa (tablets). You may also need to take the oral medicine if your pump is disconnected during the day for longer than 2 hours.

Your stoma and tube will need special care and cleaning. You must watch for signs of infection (redness, warmth, swelling). You must also keep the tube from getting kinked to assure that the medicine flows freely through it.

Do not stop using the medicine or change your dose without your doctor's advice.

This medicine can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using carbidopa and levodopa.

Each single-use Duopa cassette is for one 16-hour use. Throw away after one use.

Store cassettes in their original carton in the refrigerator, do not freeze.

Take a cassette out of the refrigerator 20 minutes before using it, to allow it to reach room temperature. Protect the cassette from light. Do not use the cold cassette right after taking it out of the refrigerator.

What happens if I miss a dose?

You may need to use extra medicine to make up a missed dose. Call your doctor for instructions if you stop your infusion or disconnect your pump for longer than 2 hours.

To avoid a missed dose, get your prescription refilled before you run out of medicine completely.

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?

Some people using carbidopa and levodopa have fallen asleep during normal daytime activities such as working, talking, eating, or driving. Avoid driving or operating machinery until you know how Duopa will affect you. Dizziness or severe drowsiness can cause falls or other accidents. Also 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 this medicine can cause side effects.

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 using Duopa.

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:

  • severe dizziness or light-headed feeling;

  • daytime sleepiness or drowsiness;

  • uncontrolled muscle movements, worsening of tremors (uncontrolled shaking);

  • intense urges such as increased sexual urges, unusual urges to gamble, or other impulsive behaviors;

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

  • numbness, tingling, or weakness in your hands or feet;

  • depression or suicidal thoughts;

  • chest pain, fast or irregular heart rate; or

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

You may also have complications from the surgical procedure needed to insert the PEG-J tube into your stomach. Tell your caregives right away if you have any of the following signs or symptoms:

  • nausea, vomiting, stomach pain;

  • severe ongoing constipation;

  • fever;

  • bloody or tarry stools;

  • severe pain in your upper stomach spreading to your back; or

  • pain, swelling, redness, warmth, or oozing around the stoma where the PEG-J tube was inserted.

Common side effects may include:

  • complications from your surgical procedure;

  • swelling around the the PEG-J tube;

  • depressed mood;

  • swelling in your hands or feet;

  • increased blood pressure (severe headache, blurred vision, pounding in your neck or ears);

  • mouth or throat pain;

  • cold symptoms such as stuffy nose, sneezing; or

  • nausea.

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.

Side effects (in more detail)

Carbidopa and levodopa enteral dosing information

Usual Adult Dose for Parkinson's Disease:

Optimum dosage is determined by careful individual titration: All doses expressed as CARBIDOPA-LEVODOPA

Immediate-release including Oral disintegrating tablets:
Initial dose: 25 mg-100 mg orally three times a day or 10 mg-100 mg orally 3 or 4 times a day
-Increase by 1 tablet every day or every other day as needed until a dose of 8 tablets is reached; may use a combination of tablets from both ratios (1:4 or 1:10) to provide the optimum dose.
Conversion from LEVODOPA:
-Levodopa should be discontinued at least 12 hours before starting carbidopa-levodopa; initiate with approximately 25% of the previous levodopa dose.
-Suggested dose for patients receiving less than levodopa 1500 mg per day: 25 mg-100 mg orally 3 or 4 times a day.
-Suggested dose for patients receiving more than levodopa 1500 mg per day: 25 mg-250 mg orally 3 or 4 times a day.

Sustained-Release Tablets (SINEMET CR):
-Initial dose (levodopa-naive): 50 mg-200 mg orally twice a day; initial dosage should be given at intervals of more than 6 hours
-Dose and dosing interval may be increased or decreased at intervals of at least 3 days based on therapeutic response
-Dose range: Most patients will require levodopa 400 to 1600 mg/day in divided doses every 4 to 8 hours during waking hours; doses of 2400 mg/day at intervals of less than 4 hours have been used, but are generally not recommended.
Conversion from IMMEDIATE-RELEASE levodopa with or without a decarboxylase inhibitor:
-For patients receiving levodopa with a decarboxylase inhibitor: Dosage with Sinemet CR should be approximately 10% higher than previous levodopa dosage; this may need to be increased to up to 30% higher depending on clinical response.
-For patients receiving levodopa without a decarboxylase inhibitor: Dosage with sustained release should be approximately 25% of previous levodopa dosage; levodopa should be discontinued at least 12 hours before starting carbidopa-levodopa

Extended-Release Capsules (RYTARY):
-Initial dose (levodopa-naive): 23.75 mg-95 mg orally 3 times a day for 3 days; on the fourth day, may increase to 36.25 mg-145 mg 3 times a day
-Dosing interval may be increased up to a maximum of 5 times a day, if tolerated
-Maximum daily dose: 612.5 mg-2450 mg
Conversion from IMMEDIATE-RELEASE carbidopa-levodopa to RYTARY: These recommended starting doses should be divided and given 3 times a day:
-For patients receiving levodopa 400 to 549 mg/day: RYTARY levodopa dose should be 855 mg/day
-For patients receiving levodopa 550 to 749 mg/day: RYTARY levodopa dose should be 1140 mg/day
-For patients receiving levodopa 750 to 949 mg/day: RYTARY levodopa dose should be 1305 mg/day
-For patients receiving levodopa 950 to 1249 mg/day: RYTARY levodopa dose should be 1755 mg/day
-For patients receiving levodopa equal or greater than 1250 mg/day: RYTARY levodopa dose should be 2205 or 2340 mg/day

-Peripheral dopa decarboxylase is saturated by carbidopa at approximately 70 to 100 mg/day; patient's receiving less than this amount of carbidopa are more likely to experience nausea and vomiting; experience with carbidopa doses greater than 200 mg/day is limited.
-RYTARY products are not interchangeable with other carbidopa-levodopa products; for patients receiving carbidopa-levodopa plus catechol-O-methyl transferase (COMT) inhibitors, the initial recommended total daily dose of levodopa may need to be increased.

Use: For the treatment of the symptoms of idiopathic Parkinson's disease, postencephalitic parkinsonism, and symptomatic parkinsonism which may follow injury to the nervous system by carbon monoxide intoxication and/or manganese intoxication.

DUOPA Enteral Suspension (carbidopa 4.63 mg-levodopa 20 mg per mL) is indicated for the treatment of motor fluctuations in patients with advanced Parkinson's disease.
-Administered into the jejunum through a PEG-J tube using a CADD-Legacy 1400 portable infusion pump; for short term administration, a naso-jejunal tube may be used.
-Total dose is composed of 3 individually adjusted doses: the MORNING bolus dose, the CONTINUOUS maintenance dose, and EXTRA BOLUS doses.

Initiation: Convert all forms of levodopa to oral immediate-release carbidopa-levodopa tablets using 1:4 ratio tablets.
-Day 1 morning dose: Provide a dose of levodopa equivalent to previous day's first levodopa dose; calculate by converting levodopa dose from mg to milliliters and add 3 milliliters of volume to prime the intestinal tube; administer over 10 to 30 minutes.
-Day 1 continuous dose: Provide levodopa dose necessary for 16 waking hours; calculate by determining the amount of levodopa received the previous day, omitting the morning and night dose.
-Extra bolus dose function is available to manage acute "off" symptoms; initially it should be set to 20 mg (1 mL), may titrate in 0.2 mL increments; extra doses should be limited to once every 2 hours.
Adjust doses based on clinical response:
MORNING DOSE is administered rapidly (over 10 to 30 minutes) to achieve a therapeutic dose level; this dose should be adjusted if there is an inadequate clinical response within 1 hour of the morning dose on the preceding day:
-For doses less than or equal to 6 mL (excluding the 3 mL to prime the tube): increase by 1 mL.
-For doses greater than 6 mL (excluding the 3 mL to prime the tube): increase by 2 mL.
-If dyskinesia or levodopa-related adverse reactions occur within 1 hour of the morning dose on the preceding day, decrease morning dose by 1 mL.
-Consider increasing the dose based on the number and volume of extra doses provided on the previous day and the patient's clinical response.
-Consider decreasing the dose for troublesome dyskinesia or other adverse reactions; for reactions lasting for a period of 1 hour or more decrease by 0.3 mL/hr; for reactions lasting for periods of 2 hours or more decrease by 0.6 mL/hr.
MAXIMUM DOSE: 1 cassette (levodopa 2000 mg) over 16 hours; patient will take their night-time dose of oral immediate-release carbidopa-levodopa.

What other drugs will affect carbidopa and levodopa?

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

Tell your doctor about all your current medicines and any you start or stop using, especially:

  • isoniazid;

  • metoclopramide;

  • blood pressure medication;

  • medicines, vitamins, or mineral supplements that contain iron; or

  • medicine to treat a psychiatric disorder (such as Abilify, Geodon, Risperdal, Seroquel, Symbyax, or Zyprexa).

This list is not complete. Other drugs may interact with carbidopa and levodopa, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Where can I get more information?

  • Your pharmacist can provide more information about carbidopa and levodopa enteral.
  • 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.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 1.01.

Date modified: November 15, 2017
Last reviewed: February 26, 2015