Carbidopa, levodopa, and entacapone and Phenytoin interaction
Carbidopa, levodopa, and entacapone and Phenytoin: the Carbidopa, levodopa, and entacapone prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Carbidopa, levodopa, and entacapone (Carbidopa, Levodopa and Entacapone) label · effective 2026-04-08
• Dopamine D2 receptor antagonists, isoniazid, phenytoin, papaverine and iron salts: may reduce efficacy of Carbidopa, levodopa and entacapone tablets ( 7.5 , 7.6 , 7.7 , 7.8 , 7.9 ) • Drugs that interfere with biliary excretion, glucuronidation and intestinal beta-glucuronidase: dose adjustment of Carbidopa, levodopa and entacapone tablets may be required (…
Carbidopa, levodopa and entacapone tablets dosage should be increased as clinically needed in patients receiving phenytoin.
Phenytoin The beneficial effects of levodopa in Parkinson’s disease have been reported to be reversed by phenytoin.
Patients taking phenytoin with carbidopa/levodopa should be carefully observed for loss of therapeutic response.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.