Brivaracetam (Briviact)
Indications
| Indication | Approved Population | Therapy Type | Status |
|---|---|---|---|
| Partial-onset (focal) seizures with or without secondary generalization | ≥1 month of age | Monotherapy or adjunctive | FDA Approved |
Brivaracetam was initially approved in 2016 for adults aged 16 years and older as adjunctive therapy. Subsequent label expansions in 2017 (monotherapy for adults), 2018 (patients ≥4 years), and 2021 (patients ≥1 month including IV formulation for pediatrics) have progressively broadened the approved population. All three formulations (tablets, oral solution, injection) carry the same indication. In pivotal trials, brivaracetam reduced focal seizure frequency by 17–26% over placebo at doses of 100–200 mg/day, with ≥50% responder rates significantly exceeding placebo.
Genetic (idiopathic) generalized epilepsy — Observational studies and narrative reviews report ≥50% responder rates of 36–84% in patients treated with 50–200 mg/day. Evidence quality: Low (no RCTs).
Post-stroke epilepsy — Small retrospective cohorts suggest favourable seizure control and tolerability in elderly patients with post-stroke seizures, with retention rates exceeding 70% at one year. Evidence quality: Very low.
Levetiracetam-intolerant patients (behavioural switch) — Brivaracetam is commonly used as a direct replacement for patients experiencing levetiracetam-related irritability and behavioural adverse effects. Overnight switching protocols have been described. Evidence quality: Low (open-label data only).
Dosing
Adult Dosing (≥16 Years)
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| Focal epilepsy — new diagnosis, monotherapy | 50 mg BID | 25–100 mg BID | 200 mg/day | No titration required; adjust based on response Can be taken with or without food |
| Focal epilepsy — adjunctive therapy, drug-resistant | 50 mg BID | 50–100 mg BID | 200 mg/day | Efficacy demonstrated in patients on 1–2 concomitant ASMs No added benefit with concomitant levetiracetam |
| Switching from levetiracetam — behavioural intolerance | 50 mg BID | 50–100 mg BID | 200 mg/day | Overnight switch is feasible; approximate ratio 50 mg BRV : 1000 mg LEV Discontinue LEV when starting BRV |
| Acute seizure management — IV bridge when oral not feasible | 50 mg BID IV | Same as oral | 200 mg/day | Administer IV over 2–15 min; up to 4 consecutive days studied 1:1 oral-to-IV conversion |
| Concomitant rifampin use | 100 mg BID | Up to 100 mg BID | 200 mg/day | Increase BRV dose by up to 100% (double) Rifampin reduces BRV levels by ~45% via CYP2C19 induction |
Pediatric Dosing (1 Month to <16 Years)
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| Focal epilepsy — weight ≥50 kg | 25–50 mg BID | 25–100 mg BID | 200 mg/day | Uses adult dosing range Tablets or oral solution |
| Focal epilepsy — weight 20 to <50 kg | 0.5–1 mg/kg BID | 0.5–2 mg/kg BID | 4 mg/kg/day | Weight-based dosing; oral solution preferred Use calibrated measuring device |
| Focal epilepsy — weight 11 to <20 kg | 0.5–1.25 mg/kg BID | 0.5–2.5 mg/kg BID | 5 mg/kg/day | Oral solution recommended Nasogastric/gastrostomy tube administration acceptable |
| Focal epilepsy — weight <11 kg | 0.75–1.5 mg/kg BID | 0.75–3 mg/kg BID | 6 mg/kg/day | Highest mg/kg dosing in youngest patients reflects faster clearance Oral solution only; discard 5 months after opening |
Hepatic Impairment Dosing
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| Adults with hepatic impairment (Child-Pugh A, B, or C) | 25 mg BID | 25–75 mg BID | 150 mg/day | AUC increases ~50–59% across all stages Same reduction applies to all Child-Pugh grades |
| Pediatric hepatic impairment (≥20 kg) | 0.5 mg/kg BID | 0.5–1.5 mg/kg BID | 3 mg/kg/day | Reduced maximum compared to normal hepatic function Monitor for excessive sedation |
Unlike most antiseizure medications, brivaracetam does not require gradual dose escalation. In all three pivotal Phase 3 trials, patients were randomized directly to target doses (50, 100, or 200 mg/day) without titration. This allows rapid attainment of therapeutic levels, which is particularly advantageous in acute settings. However, gradual withdrawal is essential when discontinuing to avoid rebound seizures.
Pharmacology
Mechanism of Action
Brivaracetam is a selective, high-affinity ligand for synaptic vesicle protein 2A (SV2A), a transmembrane glycoprotein integral to the regulation of synaptic vesicle fusion and neurotransmitter release. Compared with its structural predecessor levetiracetam, brivaracetam demonstrates 15- to 30-fold greater binding affinity for SV2A and substantially faster brain penetration, crossing the blood–brain barrier within minutes via passive diffusion. By entering recycling synaptic vesicles and binding SV2A, brivaracetam produces a frequency-dependent reduction in excitatory neurotransmitter release, preferentially dampening high-frequency neuronal firing associated with seizure propagation while leaving normal synaptic transmission relatively intact. This selective mechanism underpins both its anticonvulsant potency in animal models of focal and generalized seizures and its relatively favourable central nervous system tolerability profile compared with broader-spectrum neuromodulators.
ADME Profile
| Parameter | Value | Clinical Implication |
|---|---|---|
| Absorption | Near-complete (~100%); Tmax ~1 h (tablets), ~0.6 h (oral solution); food delays Tmax by ~3 h but does not alter AUC | Rapid onset; can be dosed without regard to meals; oral solution offers slightly faster absorption for acute settings |
| Distribution | Vd 0.5 L/kg; protein binding ≤20% (17.5%); highly lipophilic with rapid BBB penetration | Low protein binding minimises displacement interactions; rapid brain entry enables fast onset of action; Vd approximates total body water |
| Metabolism | Primary: amidase hydrolysis (non-CYP) to carboxylic acid metabolite (34% urinary excretion); Secondary: CYP2C19 hydroxylation (~16%); three inactive metabolites | CYP2C19 poor metabolizers show ~42% higher BRV exposure and may require dose reduction; low CYP interaction risk overall |
| Elimination | t½ ~9 h; >95% urinary excretion within 72 h; <10% excreted unchanged; <1% fecal | Supports twice-daily dosing; steady state reached within ~2 days; renal impairment does not meaningfully alter parent drug levels; hemodialysis unlikely to be effective |
Side Effects
| Adverse Effect | Incidence | Clinical Note |
|---|---|---|
| Somnolence / sedation | 16% (vs 8% placebo) | Dose-dependent; when combined with fatigue-related events, rates are 20% at 50 mg/day, 26% at 100 mg/day, and 27% at 200 mg/day vs 14% placebo (FDA PI); peak incidence in week 1 with substantial habituation over 3–6 weeks |
| Dizziness | 12% (vs 7% placebo) | Not clearly dose-dependent; usually mild-to-moderate and self-limiting; includes vertigo in a subset of patients |
| Adverse Effect | Incidence | Clinical Note |
|---|---|---|
| Fatigue / asthenia | 9% (vs 4% placebo) | Dose-related; highest risk early in treatment; often overlaps with somnolence reporting |
| Nausea / vomiting | 5% (vs 3% placebo) | Generally mild and transient; administration with food may help despite no PK requirement |
| Cerebellar coordination / balance disturbances | 3% (vs 1% placebo) | Includes ataxia, balance disorder, nystagmus, and gait disturbance; more prominent at higher doses |
| Irritability | 3% (vs 1% placebo) | Part of the broader psychiatric adverse event profile (~13% BRV vs ~8% placebo); generally lower severity than with levetiracetam in comparative studies |
| Constipation | 2% (vs 0% placebo) | Mild; no specific intervention typically required |
| Decreased appetite | ~2% | Observed particularly in pediatric open-label trials; monitor weight in children |
| Adverse Effect | Estimated Frequency | Typical Onset | Required Action |
|---|---|---|---|
| Suicidal behaviour / ideation | 0.43% (AED class risk) | Within first week; persists during treatment | Implement mood monitoring at every visit; consider psychiatric referral; weigh risk of untreated epilepsy against suicidality risk |
| Psychiatric reactions (psychosis, aggression, hallucinations) | ~13% (any psychiatric event); 1.7% led to discontinuation | Variable; days to weeks | Discontinue if psychotic symptoms develop; counsel families to report behavioural changes immediately |
| Hypersensitivity (bronchospasm, angioedema) | Rare (postmarketing reports) | Any time during treatment | Discontinue immediately and do not rechallenge; emergency management as indicated; brivaracetam is contraindicated in patients with prior hypersensitivity |
| Stevens-Johnson syndrome / toxic epidermal necrolysis | Very rare (postmarketing) | 3–45 days after initiation | Discontinue at first sign of rash unless clearly not drug-related; do not resume; consider dermatology consultation |
| Neutropenia (<1.0 × 109/L) | 0.3% (vs 0% placebo) | Variable | Monitor CBC if clinical suspicion; no associated infections reported in trials |
| Clinically significant leukopenia (<3.0 × 109/L) | 1.8% (vs 1.1% placebo) | Variable | Obtain CBC if recurrent infections or other signs of bone marrow suppression |
| Reason for Discontinuation | Incidence | Context |
|---|---|---|
| Psychiatric adverse reactions | 1.7% (vs 1.3% placebo) | Most commonly irritability, aggression, or depression; similar in adults and pediatric populations |
| Somnolence / fatigue | ~1–2% | Dose-related; more frequent with 100–200 mg/day; typically occurs early in treatment |
| Dizziness | ~1% | Usually transient; more prevalent in the first two weeks |
CNS-related adverse effects peak during the first week of treatment and substantially habituate over 3–6 weeks. Pooled analysis shows the incidence of new-onset CNS events drops from 18.6% in week 1 to less than 1% by week 7. The absence of mandatory titration means these effects present at full force from day one. Counsel patients and caregivers about the expected timeline and advise against driving or operating machinery until tolerance has developed. If sedation is persistent and limiting, consider reducing the dose to 25 mg twice daily before considering discontinuation.
Drug Interactions
Brivaracetam has a relatively clean drug interaction profile owing to its primary metabolism via non-CYP amidase hydrolysis, low protein binding (≤20%), and lack of significant CYP induction or inhibition. However, it is a reversible inhibitor of epoxide hydrolase, which drives the clinically important interaction with carbamazepine. CYP2C19 inducers (notably rifampin) meaningfully reduce brivaracetam exposure.
Brivaracetam does not meaningfully alter plasma levels of lamotrigine, topiramate, valproic acid, oxcarbazepine (active MHD metabolite), pregabalin, or zonisamide. It does not inhibit or induce CYP1A2, 2A6, 2B6, 2C8, 2C9, 2D6, or 3A4. At recommended doses (50 mg BID), no clinically significant interaction with combined oral contraceptives (ethinylestradiol/levonorgestrel) has been observed.
Monitoring
-
Seizure Frequency
Every visit
Routine Seizure diary review at each clinic visit; assess response after 4–8 weeks at target dose. If seizure-free, consider maintaining current dose rather than increasing. -
Mood & Behaviour
Every visit
Routine Screen for suicidal ideation, irritability, aggression, anxiety, and depressive symptoms at every encounter. Educate caregivers to recognise early behavioural changes, especially in the first months. -
Hepatic Function
Baseline
Routine Assess hepatic status before initiation to determine whether dose reduction is required (exposure increases ~50–59% across all Child-Pugh grades). No routine follow-up LFTs needed unless clinically indicated. -
CBC with Differential
As clinically indicated
Trigger-based Obtain if recurrent infections or signs of bone marrow suppression. In Phase 3 trials, 1.8% had clinically significant WBC decreases and 0.3% had significant neutropenia. -
Phenytoin Levels
When adding or stopping BRV
Trigger-based Brivaracetam can increase phenytoin concentrations by up to 20%. Check phenytoin levels within 1–2 weeks of starting or discontinuing brivaracetam. -
Skin / Dermatologic
Ongoing
Trigger-based Educate patients about signs of SJS/TEN (rash, blistering, mucosal involvement). Onset reported between 3–45 days post-initiation. Discontinue at first sign of serious rash. -
Growth (Pediatric)
Every 3–6 months
Routine Monitor weight and height in pediatric patients. Decreased appetite was observed in pediatric trials. Juvenile animal studies showed decreased brain weight at all tested doses, though clinical significance in humans is unknown.
Contraindications & Cautions
Absolute Contraindications
- Known hypersensitivity to brivaracetam or any excipient — Bronchospasm and angioedema have been reported; do not rechallenge.
Relative Contraindications (Specialist Input Recommended)
- End-stage renal disease requiring dialysis — No data available; brivaracetam is unlikely to be removed by hemodialysis given <10% unchanged renal excretion, but metabolite accumulation may occur.
- Active suicidal ideation or recent suicide attempt — All AEDs carry a class-wide risk; requires documented risk–benefit assessment and close psychiatric monitoring if prescribed.
- Concomitant levetiracetam therapy — No added therapeutic benefit demonstrated in clinical trials; concurrent use is generally not recommended.
- Severe hepatic impairment (Child-Pugh C) — Exposure increases by ~59%; prescribing requires careful dose capping (max 150 mg/day in adults) and enhanced monitoring.
Use with Caution
- History of psychiatric illness — Pre-existing depression, anxiety, or behavioural disorders may be exacerbated; 13% of patients in pivotal trials experienced psychiatric adverse events.
- CYP2C19 poor metabolizers — Brivaracetam exposure increases by ~42% in individuals with two non-functional CYP2C19 alleles; dose reduction may be necessary.
- Elderly patients (≥65 years) — Limited Phase 3 data (n=38); start at the lower end of the dosing range, reflecting potential for reduced hepatic, renal, or cardiac function.
- Patients at risk for falls — Somnolence, dizziness, and coordination disturbance may increase fall risk, particularly in polytherapy or elderly patients.
- Pregnancy — Insufficient human data; animal studies show embryofetal toxicity at exposures 4× human levels. Encourage enrolment in the NAAED Pregnancy Registry (1-888-233-2334).
Pooled analysis of 199 placebo-controlled trials of 11 different AEDs demonstrated that patients receiving any AED had approximately double the risk of suicidal thinking or behaviour compared with placebo (adjusted RR 1.8; 95% CI 1.2–2.7). The estimated incidence was 0.43% in AED-treated patients versus 0.24% in those receiving placebo. The increased risk was observed as early as one week after treatment initiation and was consistent across drug classes and indications. Clinicians should monitor all patients for the emergence of depression, suicidal thoughts, or unusual mood changes and balance this risk against the consequences of untreated epilepsy.
Patient Counselling
Purpose of Therapy
Brivaracetam is a medicine that works by regulating the release of chemical signals between nerve cells in the brain. It is used to reduce the number of partial-onset seizures. It may be used on its own or alongside other seizure medications. It will not cure epilepsy but aims to provide consistent seizure control to allow safer and more independent daily living.
How to Take
Take brivaracetam twice daily, ideally at the same times each day. Tablets should be swallowed whole with liquid — do not crush or chew. The oral liquid requires a calibrated measuring device (not a household spoon). Food does not affect how the medicine works and it can be taken with or without meals. If a dose is missed, take it as soon as remembered unless it is nearly time for the next dose — do not double up. Do not stop brivaracetam suddenly, as this may trigger more frequent or severe seizures; always taper under medical guidance.
Sources
- BRIVIACT (brivaracetam) [prescribing information]. Smyrna, GA: UCB, Inc.; Revised August 2025. FDA Label Primary source for all dosing, pharmacokinetic parameters, adverse reactions, drug interactions, and regulatory warnings cited in this monograph.
- European Medicines Agency. Briviact (brivaracetam) Summary of Product Characteristics. UCB Pharma S.A. EMA EPAR European regulatory document providing complementary pharmacokinetic and safety data, including post-marketing updates.
- Biton V, Berkovic SF, Abou-Khalil B, et al. Brivaracetam as adjunctive treatment for uncontrolled partial epilepsy in adults: a Phase III randomized, double-blind, placebo-controlled trial. Epilepsia. 2014;55(1):57–66. doi:10.1111/epi.12433 Study 1 — pivotal Phase 3 RCT comparing BRV 50 and 100 mg/day vs placebo in 299 adults with focal seizures.
- Ryvlin P, Werhahn KJ, Blaszczyk B, et al. Adjunctive brivaracetam in adults with uncontrolled focal epilepsy: results from a double-blind, randomized, placebo-controlled trial. Epilepsia. 2014;55(1):47–56. doi:10.1111/epi.12432 Study 2 — pivotal Phase 3 RCT evaluating BRV 50 mg/day vs placebo in 197 adults.
- Klein P, Schiemann J, Sperling MR, et al. A randomized, double-blind, placebo-controlled, multicenter, parallel-group study to evaluate the efficacy and safety of adjunctive brivaracetam in adult patients with uncontrolled partial-onset seizures. Epilepsia. 2015;56(12):1890–1898. doi:10.1111/epi.13212 Study 3 — pivotal Phase 3 RCT evaluating BRV 100 and 200 mg/day vs placebo in 760 adults; largest of the regulatory trials.
- Ben-Menachem E, Mammeniskiėnė R, Quarato PP, et al. Efficacy and safety of brivaracetam for partial-onset seizures in 3 pooled clinical studies. Neurology. 2016;87(3):314–323. doi:10.1212/WNL.0000000000002864 Pooled analysis of the three pivotal Phase 3 studies; provides the combined safety population data (N=1558) cited in the side effects section.
- Kanner AM, Ashman E, Gloss D, et al. Practice guideline update summary: Efficacy and tolerability of the new antiepileptic drugs I & II: Treatment of new-onset epilepsy and refractory epilepsy. Neurology. 2018;91(2):74–81. doi:10.1212/WNL.0000000000005756 AAN guideline update reviewing evidence for newer antiseizure medications including brivaracetam; supports Level C recommendation for adjunctive use in focal epilepsy.
- Gillard M, Fuks B, Leclercq K, Matagne A. Binding characteristics of brivaracetam, a selective, high affinity SV2A ligand in rat, mouse and human brain: relationship to anti-convulsant properties. Eur J Pharmacol. 2011;664(1–3):36–44. doi:10.1016/j.ejphar.2011.04.064 Characterises the 15- to 30-fold higher SV2A binding affinity of brivaracetam compared with levetiracetam and its relationship to anticonvulsant potency.
- Nicolas JM, Hannestad J, Holden D, et al. Brivaracetam, a selective high-affinity synaptic vesicle protein 2A (SV2A) ligand with preclinical evidence of high brain permeability and fast onset of action. Epilepsia. 2016;57(2):201–209. doi:10.1111/epi.13267 Demonstrates rapid brain penetration and SV2A occupancy within minutes of dosing, supporting the mechanism of action description.
- Stockis A, Sargentini-Maier ML, Otoul C. Brivaracetam pharmacokinetics and metabolism in healthy subjects. Drug Metab Dispos. 2016;44(8):1065–1073. doi:10.1124/dmd.115.068734 Comprehensive PK study establishing the ADME profile including amidase hydrolysis as the primary metabolic pathway and CYP2C19 as the secondary pathway.
- Stockis A, Watanabe S, Fauchoux N. Brivaracetam single and multiple rising oral dose study in healthy Japanese participants: influence of CYP2C19 genotype. Drug Metab Pharmacokinet. 2014;29(5):394–399. doi:10.2133/dmpk.DMPK-14-RG-007 Quantifies the impact of CYP2C19 poor-metabolizer status on brivaracetam exposure (22–42% increase).
- Meador KJ, Rosenfeld WE, Patten A, et al. Time course of drug-related treatment-emergent adverse side effects of brivaracetam. Epilepsy Behav. 2020;111:107277. doi:10.1016/j.yebeh.2020.107277 Pooled analysis demonstrating early onset and subsequent habituation of CNS adverse effects; peak in week 1 declining significantly by week 3.
- Otoul C, Watanabe S, McCabe S, Bhatt DK, Stockis A. Relative bioavailability and bioequivalence of brivaracetam 10 mg/mL oral solution and 50-mg film-coated tablet. Clin Pharmacol Drug Dev. 2017;6(3):313–317. doi:10.1002/cpdd.275 Establishes bioequivalence between oral solution and tablet formulations; confirms near-complete bioavailability for both.