Focal Seizure Treatment
For newly diagnosed focal seizures in adults, initiate monotherapy with carbamazepine, lamotrigine, or levetiracetam—all have Level A evidence for efficacy, with levetiracetam offering the best tolerability profile and fewest drug interactions. 1
Initial Monotherapy Approach
For first-line treatment of focal seizures, seven medications have Level A evidence supporting their use as monotherapy 1, 2:
Primary options (suitable for all age groups):
- Lamotrigine - Strong evidence, suitable for both men and women of childbearing age
- Levetiracetam - Strong evidence, best tolerability, minimal drug interactions
- Carbamazepine - Strong evidence, but avoid in elderly due to high interaction potential
Alternative options for adults:
- Eslicarbazepine acetate (Level A)
- Lacosamide (Level A)
- Zonisamide (Level A)
- Gabapentin (Level A, particularly for elderly)
For elderly patients specifically: Avoid carbamazepine due to drug interaction risks; gabapentin is preferred 1. Oxcarbazepine is an alternative for children, though its Level A evidence comes from a single trial that may reflect poor phenytoin tolerability rather than superior efficacy 1.
Adjunctive Therapy for Refractory Seizures
When monotherapy fails, 13 ASMs have evidence for add-on treatment, with no clear superiority among them in standard efficacy measures 2. However, cenobamate demonstrates the highest likelihood of achieving complete seizure freedom (100% responder rate) in recent network meta-analyses 3, 4:
- Cenobamate 400mg/day: RR 15 (95% CI: 7.0-39) for seizure freedom versus placebo 3
- Cenobamate 200mg/day: RR 8.7 (95% CI: 3.9-22) for seizure freedom 3
Important caveat: Cenobamate at 300mg showed increased serious adverse events (SUCRA 85.6%) compared to other ASMs, requiring careful dose titration 5.
For best tolerability in adjunctive therapy: Brivaracetam 50mg/day and levetiracetam rank lowest for treatment-emergent adverse events 3, 4.
Status Epilepticus Management
For generalized convulsive status epilepticus refractory to benzodiazepines, emergency physicians should administer fosphenytoin, levetiracetam, or valproate as second-line agents—all three have similar efficacy (Level A recommendation) 6.
Safety profile differences from the ESETT trial 6:
- Life-threatening hypotension: Levetiracetam 0.7%, Valproate 1.6%, Fosphenytoin 3.2%
- Cardiac arrhythmias: Only levetiracetam 0.7% (others 0%)
- Intubation rates: Valproate 16.8%, Levetiracetam 20%, Fosphenytoin 26.4%
None of these safety differences reached statistical significance, but levetiracetam shows the most favorable trend 6.
Clinical Decision Algorithm
Step 1 - New diagnosis focal epilepsy:
- Age <65, no comorbidities → Lamotrigine, levetiracetam, or carbamazepine
- Age ≥65 or multiple medications → Levetiracetam or gabapentin (avoid carbamazepine)
- Women of childbearing age → Lamotrigine or levetiracetam (avoid valproate)
Step 2 - Monotherapy failure:
- Switch to alternative first-line agent OR
- Add adjunctive therapy (13 options available)
Step 3 - Multiple drug failures:
- Consider cenobamate for highest seizure freedom rates, but titrate slowly due to adverse event risk 3, 5
- Brivaracetam or levetiracetam for best tolerability 3, 4
Critical pitfall: Current evidence on specific drug combinations is "almost non-existent," so combination decisions rely on individual clinician experience rather than robust data 2. Avoid combining ASMs with unfavorable pharmacokinetic or pharmacodynamic interactions 7.