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Duopa

carbidopa / levodopa
Used for Parkinson's Disease
Used for Parkinson's Disease

Duopa is a combination medication that contains carbidopa (a decarboxylase inhibitor) and levodopa (a dopamine replacement). It treats symptoms of advanced Parkinson's disease (PD), particularly movement problems. Duopa (carbidopa / levodopa) comes as a cassette that gets attached to an infusion pump. The infusion pump then sends the medication into the intestines through a feeding tube called a PEG-J tube. Duopa (carbidopa / levodopa) is given over 16 hours out of the day as a morning dose, a continuous dose, and any extra doses. Side effects include nausea, constipation, and involuntary muscle movements.

Last reviewed on January 24, 2025
basics-icon

What is Duopa (carbidopa / levodopa)?

What is Duopa (carbidopa / levodopa) used for?

How Duopa (carbidopa / levodopa) works

Duopa (carbidopa / levodopa) is a combination medication. The two active ingredients work together to help bring up the dopamine levels in the brain. This helps treat symptoms of Parkinson's disease (PD).

  • Levodopa is a dopamine replacement. Once you take levodopa, it travels into the brain where it turns into dopamine. When there's more dopamine in the brain, PD symptoms lessen.

  • Carbidopa is a dopa decarboxylase inhibitor. It stops dopa decarboxylase, a protein in the body that breaks down levodopa before levodopa can reach the brain. By blocking this protein, more levodopa can get to the brain and turn into dopamine. It helps both levodopa and dopamine reach and stay at higher levels in the brain. This enhances levodopa's ability to relieve PD symptoms.

Are you looking for information on Sinemet (carbidopa / levodopa) or Rytary (carbidopa / levodopa) instead?
When does Duopa (carbidopa / levodopa) start working?
Time passed since treatment started:
MINUTES
HOURS
DAYS
WEEKS
MONTHS
Initial effect
Full effect

Drug Facts

Common BrandsDuopa
Drug ClassDopa decarboxylase inhibitor / Dopamine replacement
Controlled Substance ClassificationNot a controlled medication
Generic StatusNo lower-cost generic available
AvailabilityPrescription only
basics-icon

What are the side effects of Duopa (carbidopa / levodopa)?

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

  • Issues related to tube placement (57%)
  • Nausea (30%)
  • Constipation (22%)
  • Redness around the area where the tube is placed (19%)
  • Involuntary movements (dyskinesia, 14%)
  • Depression (11%)
  • Discharge after the procedure where the tube is placed (11%)
  • Swelling in the legs or feet (8%)
  • High blood pressure (8%)
  • Upper respiratory tract infection (8%)
  • Mouth or throat pain (8%)
  • Collapsed lung (8%)

Other Side Effects

  • Confusion
  • Anxiety
  • Dizziness
  • Sleep problems
  • Diarrhea
  • Indigestion
  • Slow gut movement after tube placement
  • Stomach hernia
  • Fever
  • Rash
  • Hallucination
  • Unusual changes in thoughts or behavior

Serious Side Effects

Contact your healthcare provider immediately if you experience any of the following.
  • Serious stomach problems related to the procedure for tube placement: stomach pain; constipation for more than a few days; nausea; vomiting; fever; blood in your stool; dark, tarry stool
  • Withdrawal symptoms after stopping suddenly: confusion, very high fevers, sweating, muscle stiffness, irregular pulse, changes in blood pressure
  • Heart problems: chest pain that might travel to the arm, neck, or jaw; shortness of breath; cold sweat
  • Suicidal thoughts or behavior

Source: DailyMed

The following side effects have also been reported

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • Bowel blockage—stomach cramping, unable to have a bowel movement or pass gas, loss of appetite, vomiting
  • Falling asleep during daily activities
  • Heart rhythm changes—fast or irregular heartbeat, dizziness, feeling faint or lightheaded, chest pain, trouble breathing
  • Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision
  • Mood and behavior changes—anxiety, nervousness, confusion, hallucinations, irritability, hostility, thoughts of suicide or self-harm, worsening mood, feelings of depression
  • New or worsening uncontrolled and repetitive movements of the face, mouth, or upper body
  • Pain, tingling, or numbness in the hands or feet
  • Site infection—skin redness, swelling, warmth, or pain around tube site
  • Stomach bleeding—bloody or black, tar-like stools, vomiting blood or brown material that looks like coffee grounds
  • Sudden eye pain or change in vision such as blurry vision, seeing halos around lights, vision loss
  • Urges to engage in impulsive behaviors such as gambling, binge eating, sexual activity, or shopping in ways that are unusual for you

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Dark red or black saliva, sweat, or urine
  • Dizziness
  • Drowsiness
  • Headache
  • Nausea
pros-and-cons

Pros and cons of Duopa (carbidopa / levodopa)

thumbs-up

Pros

Given into your body continuously for 16 hours, so you don't need to remember to take pills

Comes with extra doses in case you feel like the medication is wearing off

thumbs-down

Cons

Must have a minor procedure done to place the PEG-J tube in your intestines

Risk of serious stomach problems since the infusion pump sends the medication directly into your gut

Can cause sleepiness and changes in behavior

pharmacist-tips

Pharmacist tips for Duopa (carbidopa / levodopa)

pharmacist
  • Duopa (carbidopa / levodopa) is given using an infusion pump that directly sends the medication into your intestines through a feeding tube. You'll need to have a minor procedure done to place this feeding tube (PEG-J tube) to your intestines.

    • Each Duopa (carbidopa / levodopa) infusion lasts for up to 16 hours. During each infusion, the pump gives you a morning dose of the medication, a continuous dose throughout the day while the pump is one, and any small extra doses as needed.

      • Duopa (carbidopa / levodopa) can cause or worsen problems controlling your body's movements (dyskinesia). These movement problems can also happen if you take extra doses of the medication often. You should take any extra doses no more than every 2 hours. Tell your prescriber if this side effect becomes bothersome so they can adjust your dose.

        • Duopa (carbidopa / levodopa) can make you very sleepy. It can also make you fall asleep suddenly, sometimes without any warning. Don't drive or do anything that you need to focus for until you know how this medication makes you feel.

          • You might feel dizzy or faint when you stand up while you're taking Duopa (carbidopa / levodopa). This is caused by a drop in your blood pressure when you stand from a sitting or lying down position. To avoid falling, stand up slowly and hold onto something stable.

            • Be sure to take Duopa (carbidopa / levodopa) at a different time than any iron-containing products. Iron and iron-containing medications, vitamins, and supplements can lessen how much Duopa (carbidopa / levodopa) gets absorbed into your body. This can lead to worsening Parkinson's symptoms.

              • Speak with your care team about nutritional tips to follow while you're taking Duopa (carbidopa / levodopa). High-protein foods, such as meat, milk, cheese, or nuts, can cause less Duopa (carbidopa / levodopa) to get absorbed into your body. This can make the medication work less well for treating symptoms of Parkinson's disease.

                Tips on how to take Duopa (carbidopa / levodopa) with the infusion pump:

                • Follow your care team's instructions on how to set up and use the infusion pump. Duopa (carbidopa / levodopa) comes in a small plastic container called a cassette that gets connected to the pump for each infusion. Also follow your care team's directions on how to care for your PEG-J tube.

                  • Store the Duopa (carbidopa / levodopa) cassettes in their original cartons in the refrigerator between 36ºF and 46ºF. Don't let them freeze. Use the medication before the expiration date that's written on the cassettes.

                    • Before you use a Duopa (carbidopa / levodopa) cassette, take it out of the refrigerator 20 minutes before your dose. Let it reach room temperature before you infuse the medication.

                      • You can disconnect the pump for short periods of time during infusion if needed, such as for a quick shower. Ask your prescriber if you need to take an extra dose of Duopa (carbidopa / levodopa) each time before you disconnect the pump. Also ask them about what to do if you need to disconnect for more than 2 hours.

                        • After the 16-hour Duopa (carbidopa / levodopa) infusion, take your usual nighttime dose of immediate-release Sinemet (carbidopa / levodopa). This helps with symptoms of Parkinson's that can happen between the time when your infusion ends and the time when your next infusion starts on the following day.

                          • Use each Duopa (carbidopa / levodopa) cassette only once and for at most 16 hours. At the end of the 16-hour infusion, throw away the cassette, even if there's still medication left inside. Never reuse an opened cassette.

                            faqs

                            Frequently asked questions about Duopa (carbidopa / levodopa)

                            Is Duopa (carbidopa / levodopa) available in the United States?
                            Yes, Duopa (carbidopa / levodopa) is available in the United States. There isn't a generic version available yet. But you can get the medication under the brand name Duopa with a prescription from a healthcare professional.
                            What is the surgery for Duopa (carbidopa / levodopa)?
                            Duopa (carbidopa / levodopa) is a liquid that's meant to be given through a feeding tube that goes to your intestines called a gastro-jejunostomy tube (PEG-J tube). You'll need to have a minor surgery done before you start treatment to place the PEG-J tube. During the surgery, a trained healthcare professional will make a small cut in the wall of your stomach to place this tube. You'll probably be sedated for the surgery. Follow up with your prescriber if you have questions about the procedure.
                            Is Duopa (carbidopa / levodopa) effective?
                            Duopa (carbidopa / levodopa) works well at treating movement symptoms related to advanced Parkinson's disease, like changes in the ability to move. In studies, people who took Duopa (carbidopa / levodopa) had an average of 4 hours less "off-time" (when the effects of the medication wear off and symptoms come back or get worse) after about 3 months of treatment. In comparison, people who took immediate-release Sinemet (carbidopa / levodopa) tablets only had an average of 2 hours less "off-time." Follow up with your prescriber about how well Duopa (carbidopa / levodopa) is working for you.
                            How long does Duopa (carbidopa / levodopa) last?
                            Duopa (carbidopa / levodopa) is typically given continuously for 16 hours each day. Studies show that during this time, people have around 13 hours of "on" time, or the period of time without troublesome movement problems. Speak with your prescriber for more information about how long Duopa (carbidopa / levodopa) lasts to help with your symptoms of Parkinson's disease.
                            How long does it take Duopa (carbidopa / levodopa) to take effect?
                            For most people, carbidopa/levodopa takes around 30 minutes to 1 hour to start working. This can vary for each person since everyone can have a different response to Duopa (carbidopa / levodopa). Speak with your prescriber if you have questions about how long it's taking Duopa (carbidopa / levodopa) to start relieving your Parkinson's symptoms.
                            Can I interrupt the Duopa (carbidopa / levodopa) infusion so I can take a shower?
                            Yes, you can interrupt the Duopa (carbidopa / levodopa) infusion and disconnect the tubing for a short period of time (less than 2 hours). Ask your prescriber if you should take an extra dose of Duopa (carbidopa / levodopa) before you disconnect the tubing. If you need to interrupt the infusion for longer than 2 hours, contact your prescriber for guidance. You might need to take a dose of immediate-release Sinemet (carbidopa / levodopa) tablets until you can reconnect your pump. Follow your care team's instructions on how to stop the infusion and disconnect the tubing from pump.
                            Can I take Sinemet (carbidopa / levodopa) while I'm taking Duopa (carbidopa / levodopa)?
                            It's common for people to take a nighttime dose of immediate-release Sinemet (carbidopa / levodopa) tablets after the 16-hour infusion time is up. This helps relieve symptoms of Parkinson's that you might have between the time when your infusion ends and the time when your next infusion starts. Your prescriber might also tell you to take a dose of immediate-release Sinemet (carbidopa / levodopa) tablets if you need to stop your Duopa (carbidopa / levodopa) infusion for more than 2 hours. Ask your prescriber for more guidance about when you might need to take immediate-release Sinemet (carbidopa / levodopa) tablets while you're taking Duopa (carbidopa / levodopa).
                            Can I save the cassette for my next dose of Duopa (carbidopa / levodopa) if there's still medication left inside?
                            No, you should throw away the Duopa (carbidopa / levodopa) cassette at the end of each 16-hour infusion period. Throw the cassette away even if there's still some medication left inside. You should use a new cassette of medication each time to make sure you get your full dose of Duopa (carbidopa / levodopa).
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                            warings-icon

                            What are the risks and warnings for Duopa (carbidopa / levodopa)?

                            Duopa (carbidopa / levodopa) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

                            risk-warning

                            Stomach problems

                            Because Duopa (carbidopa / levodopa) is given through a tube directly into your intestines, there's a risk of serious problems with your stomach and intestines. These problems can include sores, inflammation (swelling), blockages, other damage, bleeding, and infections, among others. They can lead to the serious need for surgery and can sometimes be life-threatening. Call your healthcare team right away if you have stomach pain; constipation for more than a few days; nausea; vomiting; fever; or bloody or black, tarry stool.

                            risk-warning

                            Sleepiness or falling asleep during activities

                            • Risk factors: History of drowsiness | History of sleep problems | Taking sedatives or medications that make you drowsy

                              People who've taken medications that contain levodopa, such as Duopa (carbidopa / levodopa), have fallen asleep out of nowhere, even when they didn't feel sleepy beforehand. For example, people might fall asleep in the middle of a conversation or a meal. It's also happened while people were driving, which have sometimes led to accidents.

                              Because of this risk, avoid driving or doing things that you need complete focus for until you know how Duopa (carbidopa / levodopa) affects you. This is especially important if you normally feel sleepy or if you've fallen asleep suddenly in the past. Also avoid taking medications that make you sleepy (e.g., sedatives) while you're taking Duopa (carbidopa / levodopa). They can make you feel even sleepier.

                              Tell your prescriber if you feel very sleepy during the daytime or if you fall asleep during activities that you need to concentrate for while you're taking Duopa (carbidopa / levodopa).

                              risk-warning

                              A drop in blood pressure when standing

                              People who take Duopa (carbidopa / levodopa) can have a drop in blood pressure when they stand after sitting or lying down (also called orthostatic hypotension). This can make you feel dizzy, lightheaded, or faint. It might be more likely to happen with Duopa (carbidopa / levodopa) than with immediate-release carbidopa/levodopa tablets that are swallowed.

                              Be sure to get up slowly and hold onto something stable to prevent dizziness and fainting. Let your prescriber know if you feel too dizzy when you stand up while you're taking Duopa (carbidopa / levodopa).

                              risk-warning

                              Hallucinations, changes in behavior and thoughts, and confusion

                              • Risk factors: History of certain mental health conditions

                                Duopa (carbidopa / levodopa) can raise the risk for hallucinations. Hallucinations can also happen with confusion, trouble sleeping, and lots of dreaming. Generally, hallucinations can appear shortly after you start taking Duopa (carbidopa / levodopa). And they might go away once your dose gets lowered. Let your prescriber know if you or your loved ones think that you're having hallucinations while you're taking Duopa (carbidopa / levodopa).

                                Some people who took Duopa (carbidopa / levodopa) also had confusion and other unusual changes in behavior and thinking (psychosis). Abnormal behavior and thinking can include paranoia, delusions, aggressive behavior, uneasiness, and less awareness of your surroundings. Contact your care team if you or your loved ones notice unusual behavior and thinking while you're taking this medication.

                                Because of the risk for worsening psychosis, you shouldn't take Duopa (carbidopa / levodopa) if you have certain mental health conditions. What's more, some medications that treat these mental health conditions, such as haloperidol (Haldol), can worsen symptoms of Parkinson's. They also might make Duopa (carbidopa / levodopa) work less well.

                                risk-warning

                                Difficulty controlling impulsive behavior

                                Medications for Parkinson's disease that make dopamine levels go up, like Duopa (carbidopa / levodopa), can cause people to behave more impulsively. These behaviors can include strong sexual or gambling urges, urges to spend a lot money, and binge eating. It can be hard to control these urges.

                                Let your prescriber know if any urges start to have a negative impact on your life while you're taking Duopa (carbidopa / levodopa). You might not realize that you have these urges during treatment, so your prescriber might ask you if you've recently had these behaviors at your next visit.

                                risk-warning

                                Depression and suicidal thoughts

                                In studies, 11% of people who took Duopa (carbidopa / levodopa) developed depression. Depression can raise the risk of suicidal thoughts and behaviors. Symptoms of depression can include feeling sad, hopeless, or worthless; losing interest in activities that once made you happy; changes in appetite; tiredness; and trouble sleeping.

                                Let your care team know if you or anyone around you notices any changes in your thoughts or behaviors. Call 911 right away if you or your loved ones notice that you have thoughts of hurting yourself.

                                risk-warning

                                High fevers and confusion with treatment changes

                                Although rare, stopping Duopa (carbidopa / levodopa) or lowering your dose suddenly can cause withdrawal symptoms that look similar to those of neuroleptic malignant syndrome (NMS). Symptoms can include very high fevers, confusion, muscle stiffness, irregular pulse, changes in breathing, and changes in blood pressure.

                                Don't stop taking Duopa (carbidopa / levodopa) or lower your dose without talking to your prescriber first. They can instruct you on how to do this safely. Your prescriber might lower your dose slowly or switch you to immediate-release carbidopa/levodopa tablets.

                                risk-warning

                                Nerve problems

                                • Risk factors: History of nerve problems | Taking medications or having medical conditions that cause nerve problems

                                  In studies, some people who took Duopa (carbidopa / levodopa) developed nerve problems (neuropathy). This can cause weakness, numbness, tingling, pain, or a loss of feeling, usually in the hands and feet. Tell your prescriber if you have these symptoms and if they become bothersome.

                                  risk-warning

                                  Heart problems

                                  • Risk factors: History of heart disease | History of irregular heart rhythm

                                    In studies, some people who took Duopa (carbidopa / levodopa) had a heart attack or developed an irregular heart rhythm (arrhythmia). Get medical help right away if you have chest pain, shortness of breath, a cold sweat, or irregular heart rate. These can be symptoms of a heart problem.

                                    risk-warning

                                    Rise in eye pressure in people with glaucoma

                                    Duopa (carbidopa / levodopa) might raise the pressure inside the eye in people with glaucoma. Let your optometrist or ophthalmologist know that you're taking Duopa (carbidopa / levodopa). You'll need eye exams to check your eye pressure more often while you're taking the medication to make sure that your glaucoma doesn't get worse.

                                    dosage

                                    Duopa (carbidopa / levodopa) dosage forms

                                    Typical dosing for Duopa (carbidopa / levodopa)

                                    Before you can start Duopa (carbidopa / levodopa), you need to be taking a stable dose of immediate-release Sinemet (carbidopa / levodopa) first. When you switch to Duopa (carbidopa / levodopa), your dose will depend on the total amount of carbidopa/levodopa you usually take per day.

                                    Duopa (carbidopa / levodopa) is given using a pump that sends the medication into your intestine through a PEG-J tube. The infusion pump is set up for your specific treatment plan.

                                    In general, there are three parts to each Duopa (carbidopa / levodopa) infusion:

                                    1. A morning dose that's given over 10 to 30 minutes

                                    2. A continuous dose that's infused over 16 hours

                                    3. Extra doses as needed (no more than every 2 hours)

                                    Your prescriber might adjust your dose depending on how Duopa (carbidopa / levodopa) is working for you.

                                    contraindications-icon

                                    Duopa (carbidopa / levodopa) contraindications

                                    Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Duopa (carbidopa / levodopa) will not be safe for you to take.
                                    alternatives

                                    What are alternatives to Duopa (carbidopa / levodopa)?

                                    There are a number of medications that your doctor can prescribe in place of Duopa (carbidopa / levodopa). Compare a few possible alternatives below.
                                    Duopa (carbidopa / levodopa)
                                    Used for:
                                    Used for:
                                    • Parkinson's disease (PD)

                                    • Parkinsonism (conditions that cause people to have signs and symptoms of PD, including slowness, stiffness, shakiness, and imbalance)

                                    $9.00 Lowest GoodRx priceView Prices
                                    Used for:
                                    $377.29 Lowest GoodRx priceView Prices

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                                    References

                                    Best studies we found

                                    AbbVie Inc. (2022). Duopa- carbidopa and levodopa suspension [package insert]. DailyMed.

                                    American Parkinson Disease Association. (2024). Carbidopa/levodopa: Answers to frequently asked questions.

                                    Fiedorowicz, J. G., et al. (2004). The role of monoamine oxidase inhibitors in current psychiatric practice. Journal of Psychiatric Practice.

                                    View All References (6)

                                    Gandhi, K. R., et al. (2023). Levodopa (L-dopa). StatPearls.

                                    Hitawala, A. A., et al. (2023). Percutaneous gastrostomy and jejunostomy. StatPearls.

                                    Leyden, E., et al. (2023). Carbidopa. StatPearls.

                                    MedlinePlus. (2022). Atelectasis.

                                    Parkinson’s Foundation. (n.d.). Duopa.

                                    Parkinson’s Foundation. (n.d.). Managing “off” time in Parkinson’s.

                                    GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.
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