How the interaction occurs:
The cause of this interaction is unknown.
What might happen:
The effects of your levodopa may be decreased.
What you should do about this interaction:
If your doctor prescribes these medicines together it may be necessary to adjust the dose of your levodopa.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.
1.Mendez JS, Cotzias GC, Mena I, Papavasiliou PS. Diphenylhydantoin. Blocking of levodopa effects. Arch Neurol 1975 Jan;32(1):44-6.
2.Sinemet (carbidopa/levodopa) US prescribing information. Merck & Co., Inc February, 2011.