Generic Name: Levodopa

  • What is Sinemet?

    Sinemet is used to help relieve the muscle stiffness, tremor, and weakness caused by Parkinson's disease. Sinemet contains two drugs, carbidopa and levodopa. Sinemet is also available in a longer-acting formulation called Sinemet CR.

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

    Do not take Sinemet if you are taking an antidepressant drug called a monoamine oxidase inhibitor (MAOI) or if you have stopped taking an MAOI in the last 14 days. MAOI drugs include phenelzine, tranylcypromine, and isocarboxazid. Taking Sinemet close in time to an MAOI can result in serious, sometimes fatal reactions, including high body temperature, coma, and seizures.

    If you are experiencing abnormal muscle movements while on Sinemet, you should notify your doctor because the dosage might need to be adjusted.

    Change in your diet can affect the absorption of the medication. Eating meals that are high in protein, will decrease the amount of Sinemet that is being absorbed by your body. Increased acidity in the stomach can also decrease the amount of medication that is absorbed. Patients taking multivitamins containing iron should also be aware that iron affects the absorption of the medication.

    Sinemet can make you very drowsy during the day, so be cautious when operating a car or other machinery that requires full alertness.

    While taking Sinemet, you might see a discoloration in your saliva, urine, or sweat. The color can be dark (red, brown, and black). This is not harmful; however, it might stain your clothing.

    Muscle rigidity, high temperature, rapid heartbeat or breathing, sweating, blood pressure changes, and mental changes may occur when Sinemet is reduced suddenly or discontinued. If you stop taking this medication abruptly, your doctor should monitor your condition carefully.

    Inform your doctor if you experience new or increased gambling urges, increased sexual urges, or other intense urges while taking Sinemet.

  • Who should not take Sinemet?

    Do not take Sinemet if you are sensitive to it or have ever had an allergic reaction to its ingredients. Do not take Sinemet if you have a known history of narrow-angle glaucoma (high pressure in your eye), melanoma (skin cancer), or a suspicious undiagnosed mole.

  • What should I tell my doctor before I take the first dose of Sinemet?

    Tell your doctor about all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with this drug. Also, talk to your doctor about your complete medical history, especially if you have asthma, heart or lung disease, disorder of your glands, history of heart attack or heartbeat irregularity, history of active stomach ulcer, kidney or liver problems, skin lesions, a mental or emotional disorder, or narrow-angle glaucoma (high pressure in the eye).

  • What is the usual dosage?

    The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.


    Adults: The initial recommended dose is one 25-100 milligram (mg) tablet three times a day. Your doctor will increase the dose by one tablet every day or every other day, as necessary, until a dosage of eight tablets of Sinemet 25-100 mg a day is reached. If Sinemet 10-100 mg is used, dosage may be initiated with one tablet three or four times a day. Your doctor may increase the dose by one tablet every day or every other day until a total of eight tablets (two tablets four times a day) is reached. You will be monitored and your doctor will decide on maintenance therapy and appropriate dosing.

    Sinemet CR

    Adults: The initial recommended dose is one tablet taken two times a day. Starting doses should be spaced out every 4-8 hours and then adjusted to your response. The usual long-term dose is 2-8 tablets per day, taken in divided doses every 4-8 hours during the waking day.

  • How should I take Sinemet?

    If you have been taking levodopa alone, you should stop taking it for at least 12 hours before starting to take Sinemet or Sinemet CR. Take Sinemet or Sinemet CR after meals, rather than before or between meals. Swallow Sinemet CR tablets whole, without chewing or crushing them.

  • What should I avoid while taking Sinemet?

    Avoid missing doses, and take them at evenly spaced intervals. Avoid driving or operating machinery until you know how this drug affects you.

  • What are possible food and drug interactions associated with Sinemet?

    If Sinemet is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Sinemet with the following: antacids, antiseizure drugs, antispasmodic drugs, blood pressure medications, high-protein foods, isoniazid, major tranquilizer (haloperidol or risperidone), methionine, metoclopramide, papaverine, pyridoxine (vitamin B6), tranquilizers (alprazolam, clonazepam, etc.), or tricyclic antidepressants (amitriptyline, nortriptyline, etc.).

    If you have been taking an MAO inhibitor, such as the antidepressants phenelzine and tranylcypromine, or the Parkinson's drug selegiline, you must discontinue it at least 2 weeks before starting to take Sinemet.

    A high-protein diet may impair the effectiveness of Sinemet. Iron supplements can also reduce its effect.

  • What are the possible side effects of Sinemet?

    Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

    Side effects may include: (Sinemet CR) abdominal pain, blurred vision, confusion, fatigue, hallucinations, increased heartbeat, increased libido, nausea, uncontrollable twitching or jerking, weight loss

    (Sinemet) Involuntary movements, nausea, chest pain, low blood pressure, hallucinations, vomiting, diarrhea, constipation, upset stomach, dry mouth, taste alterations, back pain, shoulder pain, muscle cramps

  • Can I receive Sinemet if I am pregnant or breastfeeding?

    The effects of Sinemet during pregnancy and breastfeeding are unknown. Tell your doctor immediately if you are pregnant, plan to become pregnant, or are breastfeeding.

  • What should I do if I miss a dose of Sinemet?

    If you miss a dose of Sinemet, take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the one you missed and return to your regular dosing schedule. Do not take two doses at once.

  • How should I store Sinemet?

    Store at room temperature.

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