Should brivaracetam be preferred over levetiracetam as an adjunctive antiseizure medication for patients needing a lower risk of neuropsychiatric adverse effects and fewer drug‑drug interactions?

Brivaracetam Should Be Preferred Over Levetiracetam for Patients at Risk of Neuropsychiatric Adverse Effects

Brivaracetam is the superior choice when neuropsychiatric tolerability is a primary concern, as it demonstrates significantly fewer behavioral and psychiatric adverse effects compared to levetiracetam while maintaining comparable efficacy. 1, 2

Neuropsychiatric Safety Profile: The Critical Differentiator

The FDA label for brivaracetam explicitly notes it is "associated with fewer behavioral or psychiatric side effects than levetiracetam" 1. This is not merely a marginal difference—the clinical evidence is compelling:

• Levetiracetam carries substantial psychiatric burden: In controlled trials, 13.3% of levetiracetam patients experienced behavioral symptoms (aggression, agitation, anger, anxiety, depression, emotional lability, hostility, irritability) compared to only 6.2% of placebo patients. Additionally, 0.7% developed psychotic symptoms requiring hospitalization 3.

• Brivaracetam shows markedly better tolerability: Irritability occurs in only 3% of brivaracetam patients versus 1% placebo—a dramatically lower rate than levetiracetam's behavioral adverse event profile 1.

• Direct switching studies confirm improvement: When patients switched overnight from levetiracetam to brivaracetam due to psychiatric concerns, 76% experienced improvement in neuropsychological adverse effects 4. A 2024 psychiatric assessment study found that anxiety and psychoticism scores, which were elevated at baseline in patients on levetiracetam, normalized after switching to brivaracetam 5.

Drug Interaction Profile: Brivaracetam's Clear Advantage

Brivaracetam has minimal drug-drug interactions, making it preferable for patients on complex medication regimens 1, 6:

• Only three clinically relevant interactions exist: rifampin (requires dose doubling), carbamazepine (may increase carbamazepine-epoxide), and phenytoin (requires monitoring) 1.

• Levetiracetam, while generally having few interactions, still carries the burden of CNS depressant effects that compound with other medications 3.

Efficacy Considerations

Both medications demonstrate comparable efficacy as adjunctive therapy for partial-onset seizures:

• Brivaracetam: 50% responder rates of 32.7-55.8% at 50 mg/day, 36-38.9% at 100 mg/day, and 37.8% at 200 mg/day 7.

• Levetiracetam: 50% responder rates of 22-33% at 1000 mg/day, 31-34% at 2000 mg/day, and 39.8% at 3000 mg/day 8.

Critical caveat: The FDA label explicitly states that "brivaracetam provided no added therapeutic benefit to levetiracetam when the two drugs were co-administered," meaning they should not be used together 1.

Practical Implementation Algorithm

When to choose brivaracetam over levetiracetam:

1. First-line scenarios for brivaracetam:

   • History of psychiatric disorders (depression, anxiety, psychosis)
   • Prior behavioral adverse effects with any antiseizure medication
   • Patients on multiple medications where drug interactions are a concern
   • Elderly patients more susceptible to CNS adverse effects

2. Conversion strategy: Direct overnight switch at a 10:1 to 15:1 ratio (levetiracetam:brivaracetam) is safe and well-tolerated 4, 7. For example, levetiracetam 1500 mg/day converts to brivaracetam 100-150 mg/day.

3. Monitoring priorities:

   • Watch for hematologic abnormalities (1.8% risk of decreased WBC <3.0 × 10⁹/L) 1
   • Assess for somnolence (16% vs 8% placebo), though less than levetiracetam's 14.8% 1, 3
   • Monitor for suicidal ideation (class effect of all antiseizure medications) 3

Cost-Effectiveness Considerations

While brivaracetam costs more than levetiracetam, a 2025 analysis found it cost-effective in Australia and potentially in Japan for high-risk populations (>24% risk of levetiracetam-induced psychiatric adverse effects) 9. In clinical practice, the cost of managing psychiatric adverse effects, emergency visits, and treatment discontinuation often justifies the higher upfront cost of brivaracetam.

Common Pitfalls to Avoid

• Do not combine brivaracetam with levetiracetam: No additive benefit exists 1.
• Do not undertitrate: Brivaracetam can be started at therapeutic doses (50-100 mg/day) without extensive titration, unlike many other antiseizure medications 1.
• Do not overlook psychiatric screening: Pre-treatment assessment for psychiatric risk factors should guide initial drug selection rather than waiting for adverse effects to emerge with levetiracetam 5, 9.

Bottom line: Brivaracetam should be the preferred initial choice for patients requiring adjunctive therapy when neuropsychiatric tolerability and minimal drug interactions are priorities, which applies to a substantial proportion of epilepsy patients given the 13.3% behavioral adverse event rate with levetiracetam.