Sinemet (Generic name: Carbidopa + Levodopa)

What is the most important information I should know about Sinemet?

• Do not stop taking Sinemet suddenly. It may take several weeks before you feel the full effects of this medicine. Stopping suddenly could make your condition much worse.
• Do not crush or chew any controlled-release forms of Sinemet (Sinemet CR). They are specially formulated to release slowly into your system. If necessary, the tablets can be split in half where they are scored, then swallowed without crushing or chewing.
• Use caution when driving, operating machinery, or performing other hazardous activities. Sinemet may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.
• Call your doctor immediately if you have uncontrollable movements of the mouth, tongue, cheeks, jaw, arms, or legs; fever; or increased body heat.

What is Sinemet?

• Sinemet is a medication used to treat Parkinson's disease. Parkinson's disease is believed to be related to low levels of a chemical called dopamine (DOE pa meen) in the brain. Levodopa is turned into dopamine in the body. Carbidopa is used with levodopa to prevent the breakdown (metabolism) of levodopa before it can reach the brain and take effect.
• Sinemet is used to treat the stiffness, tremors, spasms, and poor muscle control associated with Parkinson's disease. This medication is also used to treat the same muscular conditions when they are caused by carbon monoxide and/or manganese intoxication.
• Sinemet may also be used for purposes other than those listed in this medication guide.

What should I discuss with my healthcare provider before taking Sinemet?

• If you are already taking levodopa (Larodopa, Dopar), you will have to stop taking it at least 12 hours before you take your first dose of Sinemet.
• Do not take Sinemet if you are taking or have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate) in the past 14 days.
• Do not take this medication if you have
  • narrow-angle glaucoma (angle closure glaucoma), or
  • current or past history of malignant melanoma (a type of skin cancer).
• Before taking this medication, tell your doctor if you have:
  • any kind of heart disease, including high blood pressure, arteriosclerosis (hardening of the arteries), a previous heart attack, or an irregular heartbeat;
  • respiratory disease, including asthma and chronic obstructive pulmonary disease (COPD);
  • liver disease;
  • kidney disease;
  • an endocrine (hormonal) disease;
  • a stomach or intestinal ulcer;
  • wide-angle glaucoma; or
  • depression or any other psychiatric disorder.
• You may not be able to take Sinemet, or you may need a lower dose or special monitoring during treatment if you have any of the conditions listed above.
• Parcopa 10/100 mg and 25/100 mg tablets each contain 3.4 mg of phenylalanine; Parcopa 25/250 mg tablet contains 8.4 mg of phenylalanine. Talk to your doctor if you have phenylketonuria or have a family history of phenylketonuria.
• Sinemet is in the FDA pregnancy category C. This means that it is not known whether Sinemet will harm an unborn baby. Do not take Sinemet without first talking to your doctor if you are pregnant.
• It is also not known whether Sinemet will harm a nursing infant. Do not take Sinemet without first talking to your doctor if you are breast-feeding a baby.

How should I take Sinemet?

• Do not stop taking Sinemet suddenly. It may take several weeks before you feel the full effects of this medicine. Stopping suddenly could make your condition much worse.
• Sinemet can be taken with or without food.
• Take Sinemet exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.
• Take each dose with a full glass of water.
• Use dry hands to place Parcopa (Sinemet orally disintegrating tablets) onto your tongue where it will dissolve in seconds and can then be swallowed. Parcopa can be taken with or without water.
• Do not crush or chew any controlled-release forms of Sinemet (Sinemet CR). They are specially formulated to release slowly into your system. If necessary, the tablets can be split in half where they are scored, then swallowed without crushing or chewing.
• The regular-release formulations can be broken or crushed to make them easier to swallow.
• It is important to take Sinemet regularly to get the most benefit.
• Store Sinemet at room temperature away from moisture and heat.

What happens if I miss a dose?

• Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and only take your next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

• Seek emergency medical attention.
• Symptoms of a Sinemet overdose include muscle spasms or weakness, spasms of the eyelid, nausea, vomiting, diarrhea, irregular heartbeat, confusion, agitation, hallucinations, and unconsciousness.

What should I avoid while taking Sinemet?

• Use caution when driving, operating machinery, or performing other hazardous activities. Sinemet may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.
• Do not change the amount of protein in your diet without first talking to your doctor (high protein foods include meats, eggs, cheese and others). Protein may reduce the amount of Sinemet that gets absorbed into your body.

What are the possible side effects of Sinemet?

• If you experience any of the following serious side effects, stop taking Sinemet and seek emergency medical attention:
  • an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
  • uncontrolled movements of a part of your body;
  • seizures;
  • severe nausea, vomiting, or diarrhea;
  • an irregular heartbeat or fluttering in your chest;
  • unusual changes in mood or behavior; or
  • depression or suicidal thoughts.
• Other, less serious side effects may be more likely to occur. Continue to take Sinemet and talk to your doctor if you experience
  • mild nausea, vomiting, or decreased appetite;
  • constipation, dry mouth, or blurred vision;
  • hand tremor;
  • muscle twitches;
  • dizziness or drowsiness;
  • insomnia, confusion, or nightmares;
  • agitation or anxiety;
  • darkening of your urine, sweat, or saliva; or
  • fatigue.
• Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect Sinemet?

• You cannot take Sinemet if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), phenelzine (Nardil), or tranylcypromine (Parnate) in the past 14 days.
• If you are already taking levodopa (Larodopa, Dopar) you will have to stop taking it at least 12 hours before you take your first dose of Sinemet.
• Before taking Sinemet, tell your doctor if you are taking any of the following medicines:
  • antacids;
  • iron supplements or vitamin supplements containing iron;
  • metoclopramide (Reglan);
  • isoniazid (Nydrazid);
  • phenytoin (Dilantin);
  • a medicine to treat high blood pressure (hypertension);
  • a tricyclic antidepressant such as amitriptyline (Elavil), doxepin (Sinequan), nortriptyline (Pamelor), desipramine (Norpramin), amoxapine (Asendin), and others; or
  • a medicine used to treat psychiatric conditions (and nausea and vomiting) such as chlorpromazine (Thorazine), prochlorperazine (Compazine), promethazine (Phenergan), fluphenazine (Prolixin), mesoridazine (Serentil), thioridazine (Mellaril), trifluoperazine (Stelazine), or haloperidol (Haldol).
• You may not be able to take Sinemet, or you may require a dosage adjustment or special monitoring during treatment if you are taking any of the medicines listed above.
• Levodopa may interfere with urine tests for sugar and ketones. If you are diabetic and notice changes in your urine test results, talk to your doctor before making any changes in your diabetes medication.
• Drugs other than those listed here may also interact with Sinemet. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.