Possible food and drug interactions when taking Sinemet

Consumer Information (Cerner Multum)

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.

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

Other medical problems—The presence of other medical problems may affect the use of levodopa. Make sure you tell your doctor if you have any other medical problems, especially:

• 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