Carbidopa-Levodopa

Carbidopa-levodopa is often prescribed to help people who have Parkinson's disease. This prescription medication can also treat Parkinson-like symptoms caused by certain conditions. It is typically taken three or four times a day and comes in tablet form. While most people tolerate the drug well initially, it is common for more bothersome and serious side effects to occur over time.

What Is Carbidopa-Levodopa?

Carbidopa-levodopa (Sinemet®) is a prescription medication used to treat Parkinson's disease. It is also approved to treat parkinsonism (Parkinson-like symptoms) due to encephalitis (inflammation or infection of the brain), manganese poisoning, or carbon monoxide poisoning.
 
(Click What Is Carbidopa-Levodopa Used For? for more information, including possible off-label uses.)
 

Information on Side Effects

Just like any medicine, carbidopa-levodopa can cause side effects. Most people tolerate it relatively well at first, especially if the dose is slowly increased. If problems do occur, in many cases, they are minor and either require no treatment or are treated easily by you or your healthcare provider. As time goes by, it is common for more bothersome and serious side effects to occur.
 
Common side effects with this medication include but are not limited to:
 
  • Nausea
  • Vomiting
  • Involuntary movements.
     
(Click Side Effects of Carbidopa-Levodopa to learn more, including potentially serious reactions you should report immediately to your healthcare provider.)
 

What Should I Tell My Healthcare Provider?

Talk with your healthcare provider prior to taking carbidopa-levodopa if you have:
 
Also, let your healthcare provider know if you are:
 
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and nonprescription medicines, vitamins, and herbal supplements.
 
(Click Precautions and Warnings With Carbidopa-Levodopa to learn more, including information on who should not take the drug.)
 

Dosing Information for Carbidopa-Levodopa

The dose of carbidopa-levodopa your healthcare provider recommends will vary, depending on a number of factors, including:
 
  • How you respond to carbidopa-levodopa (especially if you develop bothersome side effects)
  • Other medications you are taking
  • Other medical conditions you may have.
     
As is always the case, do not adjust your dose unless your healthcare provider specifically tells you to do so.
 
(Click Carbidopa-Levodopa Dosage for more information.)
 

Drug Interactions

Carbidopa-levodopa can potentially interact with a number of other medicines (see Drug Interactions With Carbidopa-Levodopa).
 

What If I Take an Overdose?

People who take too much carbidopa-levodopa may experience symptoms such as:
 
If you happen to overdose on this drug, seek immediate medical attention.
 
(Click Sinemet Overdose for more information.)
 

How Should Carbidopa-Levodopa Be Stored?

Carbidopa-levodopa tablets should be stored at room temperature, away from moisture, heat, and light. Keep this and all other medications out of the reach of children.
 

What Should I Do If I Miss a Dose?

If you forget to take a dose of carbidopa-levodopa, take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and continue with your regular schedule. Do not take a double dose.
 

How Does This Medication Work?

Dopamine deficiency, caused by a loss of dopamine-producing cells in certain parts of the brain, may be responsible for many of the symptoms of Parkinson's disease. Although it would make sense to give dopamine to help treat Parkinson's, this does not work, as dopamine cannot cross the blood-brain barrier.
 
Levodopa is a precursor of dopamine, which means that the body can use it to make dopamine. Unlike dopamine, levodopa crosses the blood-brain barrier.
 
Levodopa is almost always given in combination with carbidopa. Carbidopa delays the conversion of levodopa into dopamine until it reaches the brain, preventing or diminishing some of the side effects that often accompany levodopa therapy. Carbidopa also reduces the amount of levodopa needed for Parkinson's disease treatment.
 

When and How to Take Carbidopa-Levodopa

General considerations to keep in mind when taking this medicine include the following:
 
  • Carbidopa-levodopa comes in tablet form. It is taken by mouth, usually three or four times a day.
     
  • The protein in food can decrease the absorption of carbidopa-levodopa into the body. Some healthcare providers recommended taking the medication on an empty stomach or with a low-protein diet.
     
  • Make sure to take carbidopa-levodopa at the same times each day to maintain an even level in your blood.
     
  • For this medicine to work properly, it must be taken as prescribed. Carbidopa-levodopa will not work if you stop taking it. Do not stop taking the drug suddenly without first talking to your healthcare provider.
     

Who Makes It?

Carbidopa-levodopa is made by Merck & Co., Inc., and marketed by Bristol-Myers Squibb Company.
 

Available Strengths

Carbidopa-levodopa tablets are available in the following strengths:
 
  • Carbidopa-levodopa 10-100 mg (10 mg of carbidopa and 100 mg of levodopa)
  • Carbidopa-levodopa 25-100 mg (25 mg of carbidopa and 100 mg of levodopa)
  • Carbidopa-levodopa 25-250 mg (25 mg of carbidopa and 250 mg of levodopa).
     

Generic Carbidopa-Levodopa

This drug is available in generic form (see Generic Sinemet).
 
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;
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