Does Lamotrigine Extended Release Interact with Dofetilide?
Lamotrigine Extended Release and Dofetilide have a contraindicated drug interaction according to U.S. FDA drug labeling data. Coadministration with lamotrigine ER is not recommended due to narrow therapeutic index and increased plasma levels via OCT2 inhibition. The mechanism involves inhibition of organic cationic transporter 2 (oct2)-mediated renal tubular secretion. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Contraindicated
- Lamotrigine Extended Release Class
- Anti-epileptic Agent
- Dofetilide Class
- Antiarrhythmic
- Management
- Do not take together
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Lamotrigine Extended Release and Dofetilide occurs because inhibition of organic cationic transporter 2 (oct2)-mediated renal tubular secretion. Clinically, this means coadministration with lamotrigine er is not recommended due to narrow therapeutic index and increased plasma levels via oct2 inhibition. Because of the severity of this interaction, these medications are contraindicated — meaning they should not be taken together under any circumstances. If you are currently taking both, contact your healthcare provider immediately to discuss alternatives.
What To Tell Your Doctor or Pharmacist
If you are taking Lamotrigine Extended Release and your doctor is considering prescribing Dofetilide (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask about alternative medications that do not interact with your current regimen
- Ask how frequently you should be monitored while these are co-prescribed
- Never stop or change either medication without first consulting your healthcare provider