Carbidopa, levodopa, and entacapone and Isoniazid interaction
Carbidopa, levodopa, and entacapone and Isoniazid: the Carbidopa, levodopa, and entacapone prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Carbidopa, levodopa, and entacapone (Carbidopa, Levodopa and Entacapone) label · effective 2026-04-08
Carbidopa, levodopa and entacapone tablets is contraindicated in patients: Taking nonselective monoamine oxidase (MAO) inhibitors (e.g., phenelzine and tranylcypromine).
These nonselective MAO inhibitors must be discontinued at least two weeks prior to initiating therapy with Carbidopa, levodopa and entacapone tablets.
• Concomitant use of nonselective monoamine oxidase (MAO) inhibitors ( 4 )
Therefore, the use of Carbidopa, levodopa and entacapone tablets is contraindicated in patients receiving nonselective MAO inhibitors [see Contraindications ( 4 )].
• 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 (…
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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.