Generic name: carbidopa and levodopa enteral (KAR bi doe pa and LEE voe doe pa)
Brand name: Duopa
Drug class: Dopaminergic antiparkinsonism agents

Duopa enteral suspension contains a combination of 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.

Duopa is 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 enteral suspension is a gel form of carbidopa and levodopa and is delivered at a constant rate throughout the day into the small intestine using an infusion pump via a surgically implanted tube. This delivery method avoids the stomach and improves the effectiveness of the medicine.


Duopa can cause serious side effects. Call your doctor right away if you have stomach pain, vomiting, ongoing constipation, fever, bloody or tarry stools, or problems around the tube through which this medicine is given (redness, warmth, swelling, oozing).

Before taking this medicine

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, tranylcypromine, and others.

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

  • a stomach ulcer or stomach surgery;
  • low blood pressure, or fainting spells;
  • heart disease, high blood pressure, or a heart attack;
  • problems falling asleep suddenly during the day;
  • problems with muscle movement;
  • depression or mental illness;
  • glaucoma; or
  • nerve problems that cause numbness or tingling in your hands or feet.

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

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

Duopa can slow breast milk production. Tell your doctor if you are breastfeeding.

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

How should I use Duopa?

Use Duopa exactly as prescribed by your doctor. 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 Duopa 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 Duopa 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 Duopa.

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 Duopa 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.

Get your Duopa prescription refilled before you run out of medicine completely.

Dosing information

Usual Adult Dose for Parkinson's Disease:

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.

Continuous Dose: 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.

Duopa Enteral Suspension:
-Cassettes should be brought to room temperature prior to use; see product information for complete administration instructions.
-Cassettes are specifically designed to be connected to the CADD(R) Legacy 1400 pump.
-Cassettes are for single-use only, do not use for longer than 16 hours.

Storage requirements:
-Store in freezer at -20C (-4F) prior to dispensing
-Upon dispensing, cassettes should be fully thawed in refrigerator at 2C to 8C (36F to 46F); take cartons out of transport box and separate from each other to allow even thawing (thawing may take up to 96 hours); once thawed, cartons may be repacked in a closer configuration.
-Assign a 12-week use by date once placed in refrigerator to thaw.
-Cassettes should be protected from light and kept in carton prior to use.

-Stable for 24 months at -20C and 15 weeks at 5C; 16 hours once outside the refrigerator.

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 using Duopa?

Avoid driving or hazardous activity until you know how Duopa 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 eating a diet high in iron or protein. These things can make it harder for your body to digest and absorb carbidopa and levodopa. Talk with your doctor or dietitian about the best foods to eat or avoid.

Drinking alcohol with Duopa can cause side effects.

Duopa side effects

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

Call your doctor at once if you have:

  • nausea, vomiting, stomach pain, fever;
  • ongoing constipation, bloody or tarry stools;
  • cough, trouble breathing;
  • pain, swelling, redness, warmth, or oozing around the tube in your stomach wall;
  • uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);
  • a light-headed feeling, like you might pass out;
  • chest pain, fast or irregular heartbeats;
  • daytime sleepiness or if you suddenly fall asleep after being alert;
  • numbness or weakness in your hands or feet; or
  • hallucinations, depression or suicidal thoughts.

Some people using Duopa 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. Talk with your doctor if this occurs.

Common Duopa side effects may include:

  • increased blood pressure;
  • swelling in your lower legs;
  • nausea;
  • depression; or
  • mouth or throat pain.

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 Duopa?

Using Duopa with other drugs that make you drowsy can worsen this effect. Ask your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Tell your doctor about all your other medicines, especially:

  • metoclopramide;
  • mineral or vitamin supplements that contain iron;
  • blood pressure medicine; or
  • medicine to treat mood disorders or mental illness such as schizophrenia.

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 drug interactions are listed here.