Sinemet Drug Information

LEVODOPA (Systemic)

Some frequently used brand names are:

In the U.S.—

• Atamet ¹
• Larodopa ²
• Sinemet ¹
• Sinemet CR ¹

In Canada—

• Apo-Levocarb ¹
• Nu-Levocarb ¹
• Sinemet ¹
• Sinemet CR ¹

Category

• Antidyskinetic

Description

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.)

Before Using This Medicine

When deciding if it's worth using a medicine, the risk of taking it must be carefully weighed against the benifit it can do. This is the decision you and your doctor are to make together. Concerning levodopa and for carbidopa and levodopa combination, the following aspects should be taken into account:

Allergies—Inform your doctor if you have ever experienced any unusual or allergic reaction to levodopa alone or in combination with carbidopa. Also tell your doctor if you are allergic to any other substances, like foods, preservatives, dyes.

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 conducted in adult patients only, and there is no specific data on comparing the use of levodopa or carbidopa in children with the use in other age groups.

Older adults—Elderly people are especially sensitive to the effects of levodopa. It may increase the probability of having side effects during treatment.

Other medicines—Although some medicines should not be used together at all, there are cases when 2 different medicines maybe used together even if an interaction might occur. In such cases, your doctor may advise you to change the dose, or other precautions may be required. When you are taking levodopa or carbidopa and levodopa combination, it is essential to tell your health care professional 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

Other medical problems—The existence of other medical problems may influence the use of /levodopa. You should tell your doctor if you have any other medical problems, in particular::

• 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

Proper Use of This Medicine

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.

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 vary for different patients. Adhere to the orders of your doctor or the instructions on the label . The information below includes only the average doses of levodopa or carbidopa and levodopa combination. If your dose differs, you should not change it unless your doctor tells you to do so.

The number of tablets 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. You should not double doses.

Storage—To store this medicine properly, follow the instructions below:

• 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.

Precautions While Using This Medicine

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 .

Side Effects of This Medicine

Alongside with its expected effects, any medicine may be the cause of some unwanted effects. Although not all of these side effects may happen, if they do happen they may require medical attention.

Consult your doctor immediately if any of the side effects from the list below occur:

Other side effects that may occur generally do not require any medical attention. These side effects may disappear in the course of treatment as your body gets used to the medicine. Nevertheless, inform your doctor if any of the side effects below persist or became annoying:

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 mentioned above may also happen in some patients. If you notice any other effects, tell your doctor about it.