Sinemet CR

Generic name: Carbidopa and levodopa

What is Sinemet CR?

Sinemet CR is a controlled-release tablet that may be given to help relieve the muscle stiffness, tremor, and weakness caused by Parkinson's disease. It may also be given to relieve Parkinson-like symptoms caused by encephalitis, carbon monoxide poisoning, or manganese poisoning.

Sinemet CR contains two drugs, carbidopa and levodopa. The drug that actually produces the anti-Parkinson's effect is levodopa. Carbidopa prevents vitamin B₆ from destroying levodopa, thus allowing levodopa to work more efficiently.

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

The carbidopa contained in Sinemet CR cannot eliminate side effects caused by levodopa. Since carbidopa helps levodopa reach your brain, Sinemet CR may, in fact, produce some levodopa side effects—particularly twitching, jerking, or writhing—sooner and at a lower dosage than levodopa alone. If such involuntary movements develop while you are taking Sinemet CR, you may need a dosage reduction.

Like levodopa, Sinemet CR may cause depression. Make sure your doctor knows if you have mental or emotional problems.

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

Who should not take Sinemet CR?

Do not take Sinemet CR if you are sensitive to or have ever had an allergic reaction to its ingredients. Also avoid it if you have narrow-angle glaucoma; a suspicious, undiagnosed mole or a history of melanoma; or if you are taking or have taken an MAO inhibitor within the past 14 days.

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

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 bronchial asthma, cardiovascular or lung disease, endocrine (glandular) disorder, history of heart attack or heartbeat irregularity, history of active peptic ulcer, kidney or liver problems, skin lesions, a mental or emotional disorder, or wide-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: For patients with mild to moderate symptoms, the initial recommended dose is 1 tablet of Sinemet CR taken 2 times a day. Starting doses should be spaced out every 4 to 8 hours and then adjusted to each patient's individual response. The usual long-term dose is 2 to 8 tablets per day, taken in divided doses every 4 to 8 hours during the waking day.

How should I take Sinemet CR?

If you have been taking levodopa alone, you should stop taking levodopa for at least 12 hours before starting to take Sinemet CR. Take Sinemet CR after meals, rather than before or between meals. Swallow the tablets whole without chewing or crushing them. You may see a red, brown, or black coloration in your saliva, urine, or sweat. This is not harmful, but may stain your clothes. Too much stomach acid can interfere with absorption of the medication.

Sinemet CR releases its ingredients slowly over a period of 4 to 6 hours. It is important to follow a careful schedule, taking your doses at the same time every day. You should not change the prescribed dosage or add another product for Parkinson's disease without first consulting your doctor.

What should I avoid while taking Sinemet CR?

Avoid missing doses, and take them at evenly spaced intervals day and night. Do not chew or crush the tablets.

Avoid driving or operating machinery until you know how this drug affects.

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

If Sinemet CR 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 CR with the following: antacids, antiseizure drugs, antispasmodic drugs, blood pressure medications, high-protein foods, isoniazid, major tranquilizers such as haloperidol or risperidone, methionine, metoclopramide, papaverine, pyridoxine (vitamin B6), tranquilizers such as alprazolam, and tricyclic antidepressants.

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 CR.

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

What are the possible side effects of Sinemet CR?

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: confusion, hallucinations, nausea, uncontrollable twitching or jerking

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

If you are pregnant or plan to become pregnant, inform your doctor immediately. Sinemet CR should be used during pregnancy only if the benefit outweighs the potential risk to the unborn child. It is not known whether Sinemet CR appears in breast milk. If this medication is essential to your health, your doctor may advise you to stop nursing your baby until your treatment with this drug is finished.

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

If you forget to take a dose, take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Do not take 2 doses at once.

How should I store Sinemet CR?

Store at room temperature in a tightly closed container.