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Duopa

Generic name: carbidopa and levodopa enteralKAR-bi-doe-pa-and-LEE-voe-doe-pa ]
Drug class: Dopaminergic antiparkinsonism agents

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jun 26, 2023.

What is Duopa?

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.

Warnings

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:

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.

Stability:
-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:

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:

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:

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.

Popular FAQ

Long-term administration of Dopa requires the placement of a permanent flexible feeding tube through your abdominal wall and into your stomach. This is called a PEG-jejunal (PEG-J) and placement of the tube is done by a gastroenterologist or other experienced healthcare provider as a day-stay surgery using an intravenous sedative and local anesthetic. The outer end of the tube is connected to the CADD®Legacy 1400 pump, which takes a Duopa cassette. One Duopa cassette continuously releases levodopa over 16 hours.

Duopa can also be administered in the short term via a nasojejunal tube (a tube that goes down your nose and into your stomach) with the outer end of the tube connected to the CADD®Legacy 1400 pump.

Duopa is administered over a 16-hour infusion period. The daily dose consists of

  • A morning dose
  • A continuous dose
  • Extra doses (if needed and allowed).

Step-by-Step Duopa Administration

To administer Duopa:

  1. Take one Duopa cassette out of the refrigerator and out of its carton and allow it to warm up to room temperature for 20 minutes before use. This is important otherwise you may not receive the right amount of medication. Each cassette is for one-time use only and should not be used for longer than 16 hours, even if some drug product remains.
  2. Remove the cassette clip and the cassette tube from its slot in the clip and attach the Duopa cassette to the pump. Press down on the pump, until the cassette fits tightly against the pump. Use a coin to twist the latch counterclockwise until the latch lines up straight with the arrow Make sure you attach the DUOPA cassette correctly.
  3. Remove the red cap on the end of the cassette tube then connect the stomach tube to the cassette tube. While holding the stomach tube steady, twist off the white cap on the end of the longer straight (green) connector. Do not twist the stomach tube. Connect the cassette tube to the end of the longer straight (green) connector. Do not connect to the shorter angled connector (white, blue, or violet).
  4. Turn the pump on by pressing and holding the ON/OFF button until the display turns on. Wait approximately 30 seconds for the pump to review settings. Check for STOPPED on the screen. Inspect the tubing for kinks or closed clamps. If needed straighten kinks or open clamps.
  5. START the pump. Press and hold the STOP/START button until 3 dashes appear and then disappear from the screen. Wait approximately 15 seconds for the pump to start running. Check for RUN on the display. The pump is now running. Duopa delivery will begin as programmed by your healthcare provider. If the pump will not start, a message should appear on the display.
  6. It will take between 10 minutes and 30 minutes to deliver your morning dose. To start delivery of your Morning Dose you will need to press the Morning Dose key 2 times. If the dose will not start, it may be too soon since your last dose. The time between doses is decided by your healthcare provider. Press MORNING DOSE and check for MORNING DOSE on the display and the number of doses your healthcare provider has prescribed for you. Press the MORNING DOSE key again to start delivery.
  7. After the Morning Dose finishes, the pump will automatically begin delivering the continuous rate. RUN will appear on the display.
  8. You can carry your pump around with you in its carry bag, either around your neck or over your shoulder.
  9. If you need to give an extra dose of Duopa, press EXTRA DOSE. Listen for two beeps. The display should show DOSE. If you are unable to deliver the extra dose, it may be too soon since the last dose. The time between doses is decided by your healthcare provider.
  10. When the extra dose finishes, RUN will appear on the display and the Continuous Rate will continue to run.
  11. At the end of the night (or after 16 hours) you will need to shut down the delivery of Duopa. Remove the pump from its carry and press and hold STOP/START until 3 dashes appear and the display says STOPPED.
  12. Turn the pump off by pressing and holding ON/OFF until 3 sets of dots appear and then disappear from the display and the display turns off.
  13. Clamp the cassette tube and disconnect the tubing from the longer straight (green) connector. Replace the red cap on the cassette tube.
  14. Flush the longer straight (green) connector by filling a syringe with room temperature tap or drinking water and connecting it to the green connector using the syringe connector. Do not use hot water as it could burn the wall of your stomach or intestine.
  15. Push the syringe plunger to flush the tube. Do not force the syringe if flushing the tube is difficult. Call your healthcare provider if you are unable or have difficulty flushing your tube. Remove the syringe and the syringe connector. Replace the white cap on the longer straight (green) connector.
  16. Flush the shorter angled connector (white, blue, or violet) in the same way.
  17. Remove the Duopa cassette from the pump by using a coin to twist the latch clockwise

At the end of the night (or after a maximum of 16 hours) you will need to shut down the delivery of Duopa and flush the pump.

To flush a Duopa pump:

  1. First, stop the continuous infusion. Remove the pump from its carry bag and press and hold STOP/START until 3 dashes appear and the display says STOPPED.
  2. Turn the pump off by pressing and holding ON/OFF until 3 sets of dots appear and then disappear from the display and the display turns off.
  3. Clamp the cassette tube and disconnect the tubing from the longer straight (green) connector. Replace the red cap on the cassette tube.
  4. Flush the longer straight (green) connector by filling a syringe with room temperature tap or drinking water and connecting it to the green connector using the syringe connector. Do not use hot water as it could burn the wall of your stomach or intestine.
  5. Push the syringe plunger to flush the tube. Do not force the syringe if flushing the tube is difficult. Call your healthcare provider if you are unable or have difficulty flushing your tube. Remove the syringe and the syringe connector. Replace the white cap on the longer straight (green) connector.
  6. Flush the shorter angled connector (white, blue, or violet) in the same way.
  7. Remove the Duopa cassette from the pump by using a coin to twist the latch clockwise.

Duopa is not typically worn to bed because the infusion is usually stopped after 16 hours or at bedtime and left off for the night and extended-release carbidopa/levodopa tablets taken to cover the nighttime period. However, some people experience severe “off” symptoms, muscle cramps, rigidity, and gait imbalance while in bed despite oral carbidopa/levodopa cover. These people may benefit from turning on the pump at bedtime to help them fall or stay asleep, or extending the infusion to cover the full 24 hours which means wearing Duopa to bed.

Ultimately, it comes down to the patient and how effectively their symptoms are managed to determine the dose of Duopa that is needed to control symptoms, and hence the number of cassettes needed over the 24-hour period. The timing of the cassette change should also be discussed. Some providers recommend changing the cassette at bedtime, while others recommend changing it in the morning. The benefit of always changing the cassette at bedtime allows for five extra doses to be administered if needed, which may be helpful if symptoms of wearing off occur.

Some providers may wish to prescribe a 24-hour infusion for a brief period, perhaps 2 weeks, to see if it makes a difference to symptoms, or just worsens side effects. evaluate any improvements or curtail worsening of side effects. Another approach is to increase the infusion time from 16 hours to 18 hours for a few days, and then fully transition patients to 24-hour use.

The short-acting (immediate-release) formulation of carbidopa/levodopa takes effect within about 20 to 50 minutes. The long-acting (extended-release) formulation starts to work closer to the 50-minute timeframe. Continue reading

The immediate-release (short-acting) form of carbidopa/levodopa is usually taken 3 or 4 times each day, while the extended-release (long-acting) form is typically taken 2 to 4 times each day. Continue reading

Carbidopa/levodopa is unlikely to cause high blood pressure (hypertension). It was reported in less than 1% of patients in clinical trials and is not considered a common adverse reaction related to the drug. Continue reading

More FAQ

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Duopa only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.