In the U.S.—

In Canada—

• Antidyskinetic

Levodopa is used alone or in combination with carbidopa to treat Parkinson's disease, sometimes referred to as shaking palsy. Some patients require the combination of medicine, while others benefit from levodopa alone. By improving muscle control, this medicine allows more normal movements of the body.

Levodopa alone or in combination is available only with your doctor's prescription. It is available in the following dosage forms:

Oral
• Carbidopa and Levodopa
  • Tablets (U.S. and Canada)
  • Extended-release tablets (U.S. and Canada)
• Levodopa
  • Tablets (U.S.)

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 levodopa and for carbidopa and levodopa combination, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to levodopa alone or in combination with carbidopa. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Diet—Since protein may interfere with the body's response to 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.

For patients taking levodopa by itself:

• Pyridoxine (vitamin B ₆) has been found to reduce the effects of levodopa when levodopa is taken by itself. This does not happen with the combination of carbidopa and levodopa. If you are taking levodopa by itself, do not take vitamin products containing vitamin B 6 during treatment, unless prescribed by your doctor.
• Large amounts of pyridoxine are also contained in some foods such as bananas, egg yolks, lima beans, meats, peanuts, and whole grain cereals. Check with your doctor about how much of these foods you may have in your diet while you are taking levodopa. Also, ask your health care professional for help when selecting vitamin products.

Pregnancy—Studies have not been done in pregnant women. However, studies in animals have shown that levodopa affects the baby's growth both before and after birth if given during pregnancy in doses many times the human dose.

Breast-feeding—Levodopa, alone and in carbidopa and levodopa combination, passes into breast milk and may cause unwanted side effects in the nursing baby. Also, levodopa may reduce the flow of breast milk.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of levodopa or carbidopa in children with use in other age groups.

Older adults—Elderly people are especially sensitive to the effects of levodopa. This may increase the chance of side effects during treatment.

Other 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 levodopa or carbidopa and levodopa combination, it is especially important that your health care professional know if you are taking any of the following:

• Cocaine—Cocaine use by individuals taking levodopa, alone or in combination with carbidopa, may cause an irregular heartbeat

• Haloperidol (e.g., Haldol) or
• Phenothiazines (acetophenazine [e.g., Tindal], chlorpromazine [e.g., Thorazine], fluphenazine [e.g., Prolixin], mesoridazine [e.g., Serentil], perphenazine [e.g., Trilafon], prochlorperazine [e.g., Compazine], promazine [e.g., Sparine], promethazine [e.g., Phenergan], thioridazine [e.g., Mellaril], trifluoperazine [e.g., Stelazine], triflupromazine [e.g., Vesprin], trimeprazine [e.g., Temaril]) or
• Thioxanthenes (chlorprothixene [e.g., Taractan], thiothixene [e.g., Navane])—Taking these medicines with levodopa may lessen the effects of levodopa

• Monoamine oxidase (MAO) inhibitor activity (isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate])—Taking levodopa while you are taking or within 2 weeks of taking monoamine oxidase (MAO) inhibitors may cause sudden extremely high blood pressure; at least 14 days should be allowed between stopping treatment with one medicine and starting treatment with the other medicine

• Pyridoxine (vitamin B ₆ [e.g., Hexa-Betalin]), present in some foods and vitamin formulas (for levodopa used alone)—Pyridoxine reverses the effects of levodopa

• Selegiline—Dosage of levodopa or carbidopa and levodopa combination may need to be decreased

• Diabetes mellitus (sugar diabetes)—The amount of insulin or antidiabetic medicine that you need to take may change

• Emphysema, asthma, bronchitis, or other chronic lung disease or
• Glaucoma or
• Heart or blood vessel disease or
• Hormone problems or
• Melanoma (a type of skin cancer) (or history of) or
• Mental illness—Levodopa may make the condition worse

• Kidney disease or
• Liver disease—Higher blood levels of levodopa may occur, increasing the chance of side effects

• Seizure disorders, such as epilepsy (history of)—The risk of seizures may be increased

• Stomach ulcer (history of)—The ulcer may occur again

At first, levodopa may be taken with a meal or a snack, so that any effects like stomach upset will be lessened. Later, as your body becomes accustomed to the medicine, it should be taken on an empty stomach so that it works better. Be sure to talk to your doctor about the best time for you to take this medicine.

Take this medicine only as directed. Do not take more or less of it, and do not take it more often than your doctor ordered.

For patients taking carbidopa and levodopa extended-release tablets:

• Swallow the tablet whole without crushing or chewing, unless your doctor tells you not to. If your doctor tells you to, you may break the tablet in half.

Some people must take this medicine for several weeks or months before full benefit is received. Do not stop taking it even if you do not think it is working. Instead, check with your doctor.

Dosing—

The dose of levodopa or carbidopa and levodopa combination 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 levodopa or carbidopa and levodopa combination. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets 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 your special needs.

For levodopa
• For Parkinson's disease:
  • For oral dosage form (tablets):
    • Adults and teenagers—At first, 250 milligrams (mg) two to four times a day. Your doctor may increase your dose if needed. However, the dose is usually not more than 8000 mg (8 grams) a day.
    • Children up to 12 years of age—Use and dose must be determined by your doctor.

For levodopa and carbidopa combination
• For Parkinson's disease:
  • For oral tablet dosage form:
    • Adults—At first, 1 tablet three or four times a day. Your doctor may need to change your dose, depending on how you respond to this combination medicine.
    • Children and teenagers—Use and dose must be determined by your doctor.
  • For oral extended-release tablet dosage form:
    • Adults—At first, 1 tablet two times a day. However, you may need to take more than this. Your doctor will decide the right dose for you, depending on your condition and the other medicines you may be taking for Parkinson's disease.
    • Children and teenagers—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 your next scheduled dose is within 2 hours, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking this medicine.

For patients with diabetes:

• This medicine may cause test results for urine sugar or ketones to be wrong. Check with your doctor before depending on home tests using the paper-strip or tablet method.

This medicine may cause some people to become dizzy, confused, or have blurred or double vision. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or not able to see well.

Dizziness, lightheadedness, or fainting may occur, especially when you get up from a lying or sitting position. Getting up slowly may help. If the problem continues or gets worse, check with your doctor.

For patients taking levodopa by itself:

• Pyridoxine (vitamin B ₆) has been found to reduce the effects of levodopa when levodopa is taken by itself. This does not happen with the combination of carbidopa and levodopa. If you are taking levodopa by itself, do not take vitamin products containing vitamin B 6 during treatment, unless prescribed by your doctor.
• Large amounts of pyridoxine are also contained in some foods such as bananas, egg yolks, lima beans, meats, peanuts, and whole grain cereals. Check with your doctor about how much of these foods you may have in your diet while you are taking levodopa. Also, ask your health care professional for help when selecting vitamin products.

As your condition improves and your body movements become easier, be careful not to overdo physical activities. Injuries resulting from falls may occur. Physical activities must be increased gradually to allow your body to adjust to changing balance, circulation, and coordination. This is especially important in the elderly.

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 as soon as possible if any of the following side effects occur:

• More common
  • Abnormal thinking: holding false beliefs that cannot be changed by fact;  agitation;  anxiety ;  clenching or grinding of teeth;  clumsiness or unsteadiness;  confusion;  difficulty swallowing;  dizziness;  excessive watering of mouth;  false sense of well being;  feeling faint;  general feeling of discomfort or illness;  hallucinations (seeing, hearing, or feeling things that are not there);  hand tremor, increased;  nausea or vomiting;  numbness;  unusual and uncontrolled movements of the body, including the face, tongue, arms, hands, head, and upper body ;  unusual tiredness or weakness 
  
  

• Less common
  • Blurred vision;  difficult urination ;  difficulty opening mouth;  dilated (large) pupils;  dizziness or lightheadedness when getting up from a lying or sitting position;  double vision;  fast, irregular, or pounding heartbeat ;  hot flashes;  increased blinking or spasm of eyelids;  loss of bladder control ;  mental depression;  other mood or mental changes;  skin rash;  unusual weight gain or loss 
  
  

• Rare
  • Back or leg pain;  bloody or black tarry stools;  chills;  convulsions (seizures);  fever;  high blood pressure;  inability to move eyes;  loss of appetite;  pain, tenderness, or swelling of foot or leg;  pale skin;  prolonged, painful, inappropriate penile erection;  sore throat;  stomach pain;  swelling of face;  swelling of feet or lower legs;  vomiting of blood or material that looks like coffee grounds 
  
  

Other 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. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Abdominal pain;  dryness of mouth;  loss of appetite;  nightmares;  passing gas 
  
  

• Less common
  • Constipation;  diarrhea;  flushing of skin;  headache;  hiccups;  increased sweating;  muscle twitching;  trouble in sleeping  
  
  

This medicine may sometimes cause the urine, saliva, and sweat to be darker in color than usual. The urine may at first be reddish, then turn to nearly black after being exposed to air. Some bathroom cleaning products will produce a similar effect when in contact with urine containing this medicine. This is to be expected during treatment with this medicine. Also, this medicine may cause a bitter taste, or a burning sensation of the tongue.

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