Generic name: carbidopa and levodopa [ kar-bi-DOE-pa, lee-voe-DOE-pa ]
Brand names: Parcopa, Rytary, Sinemet 10-100, Sinemet 25-100, Sinemet 25-250, Sinemet CR
Drug class: Dopaminergic antiparkinsonism agents

Medically reviewed by Drugs.com. Last updated on Apr 7, 2023.

Uses for Sinemet 25-100

Carbidopa and levodopa combination is used to treat Parkinson's disease, sometimes called shaking palsy or paralysis agitans. Parkinson's disease is a disorder of the central nervous system (brain and spinal cord).

Carbidopa and levodopa combination is also used to treat parkinsonism caused by encephalitis, or parkinsonism caused by carbon monoxide or manganese poisoning.

Dopamine is a naturally occurring substance in the brain that helps provide control of movement and activities such as walking and talking. In patients with Parkinson's disease, there is not enough dopamine in some parts of the brain. Levodopa enters the brain and helps replace the missing dopamine, which allows people to function better. By increasing the amount of dopamine in the brain, levodopa helps control symptoms and helps you to perform daily activities such as dressing, walking, and handling utensils.

This medicine is available only with your doctor's prescription.

Before using Sinemet 25-100

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of carbidopa and levodopa combination in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of Dhivy™ in the elderly. However, elderly patients are more sensitive to the effects (eg, hallucinations) of this medicine than younger adults.

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of Rytary® in the elderly.

Appropriate studies on the relationship of age to the effects of Lodosyn® have not been performed in the geriatric population, geriatric-specific problems are not expected to limit the usefulness of Lodosyn® in the elderly. However, elderly patients are more likely to have age-related kidney, liver, or heart problems, which may require caution and an adjustment in the dose for patients receiving Lodosyn®.

No information is available on the relationship of age to the effects of Sinemet® or Parcopa® in geriatric patients.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Bromopride
• Clorgyline
• Furazolidone
• Iproniazid
• Isocarboxazid
• Linezolid
• Methylene Blue
• Moclobemide
• Nialamide
• Pargyline
• Phenelzine
• Procarbazine
• Sulpiride
• Toloxatone
• Tranylcypromine

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Amisulpride
• Bupropion
• Haloperidol
• Isoniazid
• Macimorelin
• Metoclopramide
• Olanzapine
• Sapropterin

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Droxidopa
• Fosphenytoin
• Indinavir
• Iron
• Kava
• Phenylalanine
• Phenytoin
• Spiramycin
• Tyrosine

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

• High Protein Food

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Asthma or
• Depression, history of or
• Dyskinesia (abnormal muscle movements) or
• Endocrine disease or
• Heart attack, history of or
• Heart or blood vessel disease, severe or
• Heart rhythm problems (eg, ventricular tachycardia) or
• Kidney disease or
• Liver disease or
• Lung disease, severe or
• Peptic ulcer, history of or
• Psychosis (mental disorder), or history of or
• Wide-angle glaucoma (eye pressure problem)—Use with caution. May make these conditions worse.

• Melanoma (skin cancer), suspicious or a history of or
• Narrow angle glaucoma (eye pressure problem) or
• Skin lesions, undiagnosed (rashes that involve changes in color or texture of the skin)—Should not be used in patients with these conditions.

• Phenylketonuria (PKU)—The oral disintegrating tablet contains phenylalanine, which can make this condition worse.

Related/similar drugs

ropinirole, benztropine, pramipexole, carbidopa / levodopa, Sinemet, Exelon, Gocovri

Proper use of Sinemet 25-100

Take this medicine exactly as directed, and every time that you are supposed to take it. Do not stop taking your medicine unless ordered by your doctor. It is also important to not start taking other medicines for your Parkinson's disease without first talking with your doctor.

You may experience a “wearing-off” effect towards the end of the dosing interval. You should tell your doctor if you have problems with this that affect your every day life. Your doctor may want to adjust your dose.

Since protein may interfere with the body's response to carbidopa and levodopa, high protein diets should be avoided. Intake of normal amounts of protein should be spaced equally throughout the day, or taken as directed by your doctor.

If you are taking multivitamin tablets or plan to start taking them, discuss this first with your doctor. Iron salts (in vitamins) may keep this medicine from working properly.

Swallow the Dhivy™ tablet whole. If you are unable to swallow it, you may also break the tablet at the score lines. You may take this medicine with or without food.

Sinemet® tablet or Parcopa® disintegrating tablet begins to release its ingredients 30 minutes after you take it.

Swallow the extended-release capsule or sustained release tablet whole. Do not crush, break, or chew it.

If you have trouble swallowing the extended-release capsules: The capsules can be opened and the contents can be sprinkled on 1 to 2 tablespoons of applesauce. This mixture must be swallowed immediately without chewing.

If you are using the disintegrating tablet, make sure your hands are dry before you handle the tablet. Do not remove the tablet from the bottle until you are ready to take it. Place the tablet on the top of your tongue, where it will melt quickly.

Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For Parkinson's disease:
  • For oral dosage form (extended-release capsules):
    • Adults—
      • For patients starting on carbidopa and levodopa treatment: At first, one capsule 3 times a day for the first 3 days. Your doctor may adjust your dose as needed and tolerated. However, the dose is usually not more than 10 capsules per day.
      • For patients taking carbidopa and levodopa already: At first, 3 or 4 capsules 3 times a day. Your doctor may adjust your dose as needed and tolerated. However, the dose is usually not more than 10 capsules per day.
    • Children—Use and dose must be determined by your doctor.
  • For oral dosage form (disintegrating tablets):
    • Adults—
      • For patients starting on carbidopa and levodopa treatment: At first, one tablet 3 or 4 times a day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 8 tablets per day.
      • For patients taking levodopa already: Levodopa should be discontinued at least 12 hours before starting Parcopa®. The starting dose is one tablet 3 or 4 times a day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 8 tablets per day.
    • Children—Use and dose must be determined by your doctor.
  • For oral dosage form (sustained release tablets):
    • Adults—
      • For patients switching from Sinemet® to Sinemet® CR: The starting dose is based on the amount of Sinemet® you are currently taking per day. Your doctor may adjust your dose as needed.
      • For patients taking levodopa already: Levodopa should be discontinued at least 12 hours before starting Sinemet® CR. The starting dose is one tablet 2 times a day. Your doctor may adjust your dose as needed.
      • For patients not taking levodopa: At first, one tablet 2 times a day. Your doctor may adjust your dose as needed.
    • Children—Use and dose must be determined by your doctor.
  • For oral dosage form (tablets):
    • Adults—
      • For patients starting on carbidopa and levodopa treatment: At first, one tablet 3 or 4 times a day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 200 mg per day.
      • For patients taking levodopa already: Levodopa should be discontinued at least 12 hours before starting Lodosyn® plus levodopa or Sinemet®. The starting dose is one tablet 3 or 4 times a day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 200 mg per day.
      • For patients taking carbidopa and levodopa already: 25 milligrams (mg) of Lodosyn® per day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 200 mg per day.
    • Children—Use and dose must be determined by your doctor.
• For Parkinson's disease, parkinsonism caused by encephalitis, or parkinsonism caused by carbon monoxide or manganese poisoning:
  • For oral dosage form (tablets):
    • Adults—At first, 25 milligrams (mg) carbidopa and 100 mg levodopa (1 tablet) 3 times a day. Your doctor may adjust your dose as needed and tolerated. However, the dose is usually not more than 8 whole tablets per day.
    • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions while using Sinemet 25-100

It is very important that your doctor check your progress at regular visits to allow changes in your dose. Blood and urine tests may be needed to check for any unwanted effects.

Do not take this medicine together with non-selective MAO inhibitor (eg, phenelzine, linezolid, tranylcypromine, Nardil®, Parnate®, Zyvox®) in the past 2 weeks.

Do not stop taking this medicine without first checking with your doctor. Your doctor may want you to gradually reduce the amount you are taking before stopping completely.

Check with your doctor right away if you are having convulsions (seizures), difficulty with breathing, a fast heartbeat, a high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin, or tiredness. These could be symptoms of a serious condition called neuroleptic malignant syndrome (NMS).

This medicine may cause dizziness, drowsiness, trouble in controlling movements, or trouble concentrating, or seeing clearly. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

It is important that your doctor check your skin regularly for signs of a skin cancer called melanoma. If you notice any unusual red, brown, or black spots on your skin, talk to your doctor right away.

If you develop any unusual or strange thoughts and behavior while receiving this medicine, be sure to discuss it with your doctor. Other changes might be confusion, worsening of depression, visual hallucinations (seeing things that are not there), suicidal thoughts, and unusual excitement, nervousness, or irritability.

It is possible that a dark color (red, brown, or black) may appear in saliva, urine, or sweat after taking this medicine. The color may cause some of your garments to become discolored. This is normal and nothing to worry about.

It is possible that you may become nauseous, especially when you are first starting your medicine.

This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. Also tell your doctor if you have sudden or strong feelings, such as feeling nervous, angry, restless, violent, or scared. If you, your child, or your caregiver notice any of these adverse effects, tell your doctor or your child's doctor right away.

Some people who have used this medicine had unusual changes in their behavior. Talk with your doctor right away if you start having problems with gambling or an increased interest in sex while using this medicine.

This medicine may cause uncontrolled sudden movements (dyskinesia) or make such movements you already have worse or more frequent. Tell your doctor if this happens.

Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects of Sinemet 25-100

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

• Twitching, twisting, uncontrolled repetitive movements of the tongue, lips, face, arms, or legs

Less common

• Bladder pain
• bloody or cloudy urine
• chest pain
• confusion
• difficult, burning, or painful urination
• discouragement
• feeling sad or empty
• frequent urge to urinate
• inability to move the eyes
• increased blinking or spasms of the eyelid
• irritability
• lack of appetite
• loss of interest or pleasure
• lower back or side pain
• seeing, hearing, or feeling things that are not there
• sticking out of tongue
• tiredness
• trouble concentrating
• trouble in breathing, speaking, or swallowing
• trouble sleeping
• uncontrolled twisting movements of the neck, trunk, arms, or legs
• unusual facial expressions

Incidence not known

• Anxiety
• black, tarry stools
• bluish color
• blurred vision
• changes in skin color
• chest discomfort
• chills
• convulsions
• cough or hoarseness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• dry mouth
• false beliefs that cannot be changed by facts
• fast, irregular, pounding, or racing heartbeat or pulse
• feelings about hurting oneself or others
• fever with or without chills
• general feeling of tiredness or weakness
• high fever
• hyperventilation
• increased in sexual ability, desire, drive, or performance
• increased interest in sexual intercourse
• increased sweating
• large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
• loss of bladder control
• lower back or side pain
• nausea
• pain
• pain or discomfort in the arms, jaw, back, or neck
• restlessness
• seeing, hearing, or feeling things that are not there
• severe muscle stiffness
• shaking
• sore throat
• sores, ulcers, or white spots on the lips or in the mouth
• swelling of the foot or leg
• swollen glands
• tenderness
• tiredness
• unusual bleeding or bruising
• unusual tiredness or weakness
• unusually pale skin
• vomiting

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

• Acid or sour stomach
• back or shoulder pain
• belching
• body aches or pain
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• diarrhea
• difficulty having a bowel movement (stool)
• ear congestion
• headache
• heartburn
• indigestion
• loss of voice
• muscle cramps
• nasal congestion
• runny nose
• sneezing
• stomach discomfort, upset, or pain
• unusual dreams
• weight loss

Incidence not known

• Abdominal or stomach distress
• bad, unusual, or unpleasant (after) taste
• belching
• change in taste
• dark sweat
• double vision
• enlarged pupils
• feeling of warmth
• hair loss or thinning of the hair
• lack or loss of strength
• redness of the face, neck, arms, and occasionally, upper chest
• seeing double
• skin rash, hives or welts, itching

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Commonly used brand name(s)

In the U.S.

• Parcopa
• Rytary
• Sinemet 10-100
• Sinemet 25-100
• Sinemet 25-250
• Sinemet CR

In Canada

• Sinemet 100/10
• Sinemet 100/25
• Sinemet 250/25
• Sinemet CR 100/25
• Sinemet CR 200/50

Available Dosage Forms:

• Tablet, Extended Release
• Tablet
• Capsule, Extended Release
• Tablet, Disintegrating

Therapeutic Class: Antiparkinsonian

Pharmacologic Class: Decarboxylase Inhibitor

Frequently asked questions

• How long does it take carbidopa levodopa to work?
• How often should carbidopa/levodopa be taken?
• Can carbidopa/levodopa cause high blood pressure?
• What foods should be avoided when taking levodopa?
• Is Rytary better than Sinemet?
• What is the difference between carbidopa, levodopa, and Rytary?
• How long does it take for Rytary to start working?
• How long does Rytary stay in your system?

View more FAQ

Further information

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

Medical Disclaimer