Dofetilide and Lamotrigine interaction

Dofetilide and Lamotrigine: the Lamotrigine prescribing label flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Lamotrigine (SUBVENITE) label · effective 2026-06-04

Major

Coadministration of SUBVENITE with OCT2 substrates with a narrow therapeutic index (e.g., dofetilide) is not recommended.

Drug interactionsnames DofetilideView label on DailyMed

Minor

Cardiac Rhythm and Conduction Abnormalities In vitro testing showed that lamotrigine exhibits Class IB antiarrhythmic activity at therapeutically relevant concentrations [see Clinical Pharmacology ( 12.2 )] .

Warnings and precautionsby drug classView label on DailyMed

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Not 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.