Carbidopa and levodopa and Iron interaction
Carbidopa and levodopa and Iron: the Carbidopa and levodopa prescribing label describe 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 and levodopa (Duopa) label · effective 2026-03-19
Dopamine D2 receptor antagonists, isoniazid, iron salts, and high-protein diet may reduce the effectiveness of DUOPA ( 7.3 , 7.4 , 7.5 )
Iron Salts Iron salts or multi-vitamins containing iron salts can form chelates with levodopa, carbidopa, and can cause a reduction in the bioavailability of DUOPA.
If iron salts or multi-vitamins containing iron salts are co-administered with DUOPA, monitor patients for worsening Parkinson’s symptoms.
Curated guidance for Iron
Iron reduces the absorption of these medicines; take them a few hours apart.
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.