Add-On Seizure Medicines Help, With Cenobamate Leading

What was studied

This study combined results from 35 studies in a network meta-analysis. It looked at adolescents and adults with focal epilepsy who were taking an additional antiseizure medicine on top of their usual treatment. The medicines included approved and investigational third-generation antiseizure medications.

The researchers searched major medical databases through August 2025. They compared how well these add-on medicines worked over 8-week and 12-week maintenance periods, including how many people had their seizures cut by at least half and how many became seizure-free. They also looked at safety, including treatment-emergent adverse events, adverse events leading to treatment discontinuation, and how many people stayed on treatment.

What they found

Compared with placebo, all of the add-on antiseizure medicines showed significantly higher responder rates. Cenobamate, especially at 200 mg/day and 400 mg/day, showed the highest 100% responder rates during both the 8-week and 12-week maintenance periods in this analysis.

All medicines had treatment retention similar to placebo. For overall treatment-emergent adverse events, brivaracetam 50 mg/day ranked lowest among individual doses, and pooled brivaracetam ranked lowest overall. For adverse events leading to treatment discontinuation, cenobamate ranked lower than placebo in this analysis.

Limits of the evidence

This was a network meta-analysis, which mainly compares treatments indirectly across different studies rather than head-to-head in the same trial. That means the rankings are informative but not the same as direct comparison trials.

The abstract does not give details about the ages, seizure severity, prior medicines, or how many people were in each drug group, so it is hard to know how well the results apply to every patient. The study focused on short maintenance periods of 8 to 12 weeks, so it cannot show long-term seizure control or long-term safety. It also included investigational medicines, which may not be available in routine care.

For families and caregivers

For families, this study suggests that several newer add-on medicines can help adolescents and adults with focal epilepsy when seizures are not fully controlled. It also suggests that cenobamate had the greatest likelihood of seizure freedom among the medicines studied in this analysis.

Still, this does not mean one medicine is automatically best for every person. Real treatment choices also depend on age, other health conditions, current medicines, side effects, cost, and how a person responds over time.

What to watch next

More direct head-to-head trials and longer studies could help clarify differences in seizure freedom and side effects over longer periods.

Terms in this summary

focal epilepsy

Epilepsy in which seizures start in one area of the brain.

adjunctive treatment

A medicine added to a person’s usual treatment, rather than used alone.

network meta-analysis

A study method that combines many trials to compare several treatments, even when some have not been tested directly against each other.

placebo

An inactive treatment used for comparison in research studies.

responder rate

The share of people who had a certain level of improvement, such as at least a 50% drop in seizures.

retention rate

How many people stayed on the treatment during the study.

treatment-emergent adverse events

Side effects or other unwanted problems that happened after starting the treatment.

seizure freedom

Having no seizures during the time period measured in the study.