Drug Interaction Report

Alcohol can increase the nervous system side effects of levodopa such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with levodopa. You may experience reduced effectiveness of levodopa in the presence of foods or enteral (tube) feedings with a high protein content. This may make the symptoms of Parkinson's disease worse. Talk with your doctor or nutrition counselor about the best foods to eat while you are taking this medication. Contact your doctor if your condition changes.

Grapefruit juice may increase the blood levels of certain medications such as norethindrone. You may want to limit your consumption of grapefruit and grapefruit juice during treatment with norethindrone. However, if you have been regularly consuming grapefruit or grapefruit juice with the medication, then it is advisable for you to talk with your doctor before changing the amounts of these products in your diet, as this may alter the effects of your medication. Contact your doctor if your condition changes or you experience increased side effects. Orange juice is not expected to interact.

Levodopa and multivitamin with minerals should not be taken orally at the same time. Products that contain iron may interfere with the absorption of levodopa and reduce its effectiveness. You should separate the dosing of these medications by as much as possible. Contact your doctor if your Parkinson symptoms worsen. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Consumer information for this interaction is not currently available.

MONITOR: Coadministration of ethinyl estradiol may increase the plasma concentrations of drugs that are primarily metabolized by CYP450 1A2. In a study of 30 healthy volunteers administered the CYP450 1A2 substrate tizanidine, the systemic exposure (AUC) of tizanidine was 3.9 times greater in women using an oral contraceptive containing ethinyl estradiol.

MANAGEMENT: Patients should be monitored for increased adverse effects of the CYP450 1A2 substrate during concomitant use with ethinyl estradiol. Product labeling for the specific CYP450 1A2 substrate should be consulted for additional recommendations.

Information for this minor interaction is available on the professional version.

Information for this minor interaction is available on the professional version.

Information for this minor interaction is available on the professional version.