Major Drug Interactions with Lacosamide
Lacosamide, an antiepileptic drug, primarily interacts through CYP2C19 metabolism and cardiac sodium channel effects. Strong CYP2C19 inducers like rifampin reduce lacosamide levels by 20-40%, potentially lowering seizure control; inhibitors like fluconazole increase levels by up to 15%.[1] Carbamazepine and phenytoin, common in epilepsy regimens, decrease lacosamide exposure by 20-30% via induction.[2]
Drugs prolonging PR interval, such as beta-blockers (e.g., metoprolol), calcium channel blockers (e.g., verapamil), or Class I/III antiarrhythmics (e.g., amiodarone, propafenone), heighten AV block risk when combined with lacosamide, which itself slows conduction.[1][3]
Interactions Raising Seizure Risk
Central nervous system depressants like opioids, benzodiazepines, alcohol, or other antiepileptics (e.g., phenobarbital) amplify drowsiness, dizziness, and ataxia. Avoid or use lowest doses.[1] MAO inhibitors may provoke hypertensive crises due to lacosamide's sympathomimetic potential.[3]
Cardiac and Electrolyte Concerns
Lacosamide carries a risk of atrial fibrillation/flutter, worsened by potassium-lowering diuretics or drugs causing hypokalemia (e.g., loop diuretics). Monitor ECG and electrolytes in patients on digoxin, which shares AV node sensitivity.[1][2]
Common Over-the-Counter and Herbal Interactions
Omeprazole, a CYP2C19 inhibitor in many antacids, mildly raises lacosamide levels. St. John's wort induces metabolism, reducing efficacy. Avoid alcohol, as it intensifies CNS side effects.[3]
Food and Lifestyle Factors
No major food interactions; take with or without meals. High-fat meals delay absorption slightly but not clinically.[1] Driving or operating machinery worsens impairment risk with interacting sedatives.
Management and Monitoring
Adjust lacosamide dose with strong CYP inducers (increase by 50 mg/day). Baseline ECG recommended; repeat if on PR-prolonging drugs. No routine level monitoring needed.[2][3]
[1]: Drugs.com - Lacosamide Interactions
[2]: FDA Label - Vimpat (lacosamide)
[3]: Lexicomp - Lacosamide