Levodopa and Carbidopa
The combination of levodopa and carbidopa is used to treat the symptoms of Parkinson’s disease and 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. 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. Levodopa is in a class of medications called central nervous system agents. It works by being 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 allows for a lower dose of levodopa, which causes less nausea and vomiting.
🔔 How should this medicine be used?
The combination of levodopa and carbidopa comes as a regular tablet, an orally disintegrating tablet, an extended-release (long-acting) tablet, and an extended-release (long-acting) capsule to take by mouth. The combination of levodopa and carbidopa also comes as a suspension (liquid) to be given into your stomach through a PEG-J tube (a tube surgically inserted through the skin and stomach wall) or sometimes through a naso-jejunal tube (NJ; a tube inserted into your nose and down to your stomach) using a special infusion pump. The regular and orally disintegrating tablets are usually taken three or four times a day. The extended-release tablet is usually taken two to four times a day. The extended-release capsule is usually taken three to five times a day. The suspension is usually given as a morning dose (given by infusion over 10 to 30 minutes) and then as a continuous dose (given by infusion over 16 hours), with extra doses given no more than once every 2 hours as needed to control your symptoms. Take levodopa and carbidopa at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take levodopa and carbidopa exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the extended-release tablets whole; do not chew or crush them.
Swallow the extended-release capsules whole; do not chew, divide, or crush them. Take the first daily dose of the extended-release capsule 1 to 2 hours before eating. If you have trouble swallowing, you can carefully open the extended-release capsule, sprinkle the entire contents on 1 to 2 tablespoons (15 to 30 mL) of apple sauce, and consume the mixture immediately. Do not store the mixture for future use.
To take the orally disintegrating tablet, remove the tablet from the bottle using dry hands and immediately place it in your mouth. The tablet will quickly dissolve and can be swallowed with saliva. No water is needed to swallow disintegrating tablets.
If you are switching from levodopa (Dopar or Larodopa; no longer available in the US) to the combination of levodopa and carbidopa, follow your doctor’s instructions. You will probably be told to wait at least 12 hours after your last dose of levodopa to take your first dose of levodopa and carbidopa.
Your doctor may start you on a low dose of levodopa and carbidopa and gradually increase your dose of the regular or orally disintegrating tablet every day or every other day as needed. Your doctor may gradually increase your dose of the extended-release tablet or capsule after 3 days as needed.
To take the suspension, your doctor or pharmacist will show you how to use the pump to give your medication. Read the written instructions that come with the pump and the medication. Look at the diagrams carefully and be sure that you recognize all the parts of the pump and description of the keys. Ask your doctor or pharmacist to explain any part you do not understand.
Levodopa and carbidopa suspension comes in a single-use cassette to connect to the pump that will control the amount of medication you will receive during your infusion. Before use, remove the cassette containing the medication from the refrigerator and allow it to sit at room temperature for 20 minutes. Do not reuse a cassette or use it for longer than 16 hours. Dispose of the cassette at the end of the infusion even if it still contains medication.
When you begin taking levodopa and carbidopa suspension, your doctor will adjust your morning and continuous infusion doses and possibly the doses of your other Parkinson’s disease medications to best control your symptoms. It usually takes about 5 days to reach a stable dose of the suspension, but your doses may need to be changed again over time depending on your ongoing response to the medication. Your prescribed dose of the suspension will be programmed into your pump by your doctor. Do not change the dose or settings on your pump unless you are told to do so by your doctor. Be careful to make sure your PEG-J tube does not become kinked, knotted, or blocked as this will affect the amount of medication that you receive.
Levodopa and carbidopa controls Parkinson’s disease but does not cure it. It may take several months before you feel the full benefit of levodopa and carbidopa. Continue to take levodopa and carbidopa even if you feel well. Do not stop taking levodopa and carbidopa without talking to your doctor. If you suddenly stop taking levodopa and carbidopa, you could develop a serious syndrome that causes fever, rigid muscles, unusual body movements, and confusion. Your doctor will probably decrease your dose gradually. If your doctor tells you to stop taking levodopa and carbidopa suspension, a healthcare professional will remove your PEG-J tube; do not remove the tube yourself.
Ask your pharmacist or doctor for a copy of the manufacturer’s patient information sheet for levodopa and carbidopa and also the Medication Guide for levodopa and carbidopa suspension.