Prescription medication · Anticonvulsant
felbamate
Also sold as Felbatol. Felbamate treats partial seizures in adults, both with and without generalization.
Data updated 2026-05-15
- 1,714
- FDA reportsRarely reported
- 16
- InteractionsSeveral interactions
- 94% less
- Generic vs brandHuge savings
- $14.03
- Brand price (NADAC)
What the data shows
felbamate (Felbatol) is a prescription Anticonvulsant, among the least-reported drugs the FDA tracks (1,714 FDA reports), whose generic costs a fraction of the brand (about 94% less).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
felbamate (Felbatol) is a prescription Anticonvulsant. Felbamate treats partial seizures in adults, both with and without generalization.
Felbamate is a medicine used to treat seizures. It is usually only prescribed when other treatments haven't worked well enough due to the risk of serious side effects.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Brand Price
$14.03/unit
Generic Price
$0.82/unit
Generic Savings
94%
Generic Available
Yes (7 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: FELBAMATE 400 MG TABLET
Same CMS presentation as the headline generic unit price above (3 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: -16.8% vs prior release.
| Effective | NADAC / unit | vs prior | NDCs |
|---|---|---|---|
| December 20, 2023 | $1.00/EA | - | 1 |
| July 17, 2024 | $0.9920/EA | -0.9% | 1 |
| December 18, 2024 | $0.8249/EA | -16.8% | 7 |
What it does
Felbamate treats partial seizures in adults, both with and without generalization.
Common side effects
Loss of appetite, Vomiting, Trouble sleeping
Key warnings
Felbamate can cause a severe type of anemia called aplastic anemia.
The sections below are summarized in plain English from felbamate's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Felbamate is an anticonvulsant, meaning it helps to control seizures. The exact way it works in the brain is not fully understood. It is thought to affect certain chemicals in the brain that are involved in seizures.
Side Effects (from patient reports)
Based on 1,714 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for felbamate, by number of reports
- Seizure
Seizure
345 reports
- Convulsion 124
Convulsion
124 reports
- Somnolence 108
Somnolence
108 reports
- Condition Aggravated 92
Condition Aggravated
92 reports
- Fatigue 85
Fatigue
85 reports
- Drug Interaction 71
Drug Interaction
71 reports
- Toxicity To Various Agents 71
Toxicity To Various Agents
71 reports
- Vomiting 70
Vomiting
70 reports
- Fall 60
Fall
60 reports
- Generalised Tonic-Clonic Seizure 60
Generalised Tonic-Clonic Seizure
60 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for felbamate each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where felbamate sits
felbamate has more FDA adverse-event reports than 11% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is felbamate; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 1,714 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
1,714
Reports Mentioning Death
86
5.0% of reports — not proof of cause
Hospitalization Reports
529
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | SEIZURE | 345 |
| 3 | CONVULSION | 124 |
| 5 | SOMNOLENCE | 108 |
| 6 | CONDITION AGGRAVATED | 92 |
| 7 | FATIGUE | 85 |
| 8 | DRUG INTERACTION | 71 |
| 9 | TOXICITY TO VARIOUS AGENTS | 71 |
| 10 | VOMITING | 70 |
| 11 | FALL | 60 |
| 12 | GENERALISED TONIC-CLONIC SEIZURE | 60 |
| 13 | DIARRHOEA | 59 |
| 14 | WEIGHT DECREASED | 52 |
| 15 | PNEUMONIA | 50 |
| 16 | DECREASED APPETITE | 47 |
| 17 | EPILEPSY | 47 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Felbamate can cause a severe type of anemia called aplastic anemia. This condition is very serious and can be deadly. Because of this risk, felbamate should only be used if your epilepsy is very severe and other treatments have not worked. Felbamate can also cause liver failure. Talk to your doctor about these risks before starting felbamate.
Known Drug Interactions
The selective serotonin reuptake inhibitors sertraline (weak CYP3A4 inducer) and fluoxetine (CYP2D6 inhibitor), and the anti-epileptic drug felbamate (CYP2C19 inhibitor and CYP3A4 inducer) do not affect the pharmacokinetics of clonazepam.
Mechanism: Felbamate does not change the levels of clonazepam in the body or how it is processed.
Effects of Erythromycin on Felbamate The coadministration of erythromycin (1000 mg/day) for 10 days did not alter the pharmacokinetic parameters of C max , C min , AUC, Cl/kg or T max at felbamate daily doses of 3000 or 3600 mg/day in 10 otherwise healthy subjects with epilepsy.
Mechanism: Erythromycin does not change the amount of felbamate that stays in your system.
CBZ epoxide ↓ ↑ ↓ Phenobarbital ↑ ↓ Specific Effects of Felbamate on Other Antiepileptic Drugs Phenytoin Felbamate causes an increase in steady-state phenytoin plasma concentrations. Phenobarbital Coadministration of felbamate with phenobarbital causes an increase in phenobarbital plasma concentrations. In 12 otherwise healthy male volunteers ingesting phenobarbital, the steady-state trough (C min ) phenobarbital concentration was 14.2 micrograms/mL.
Mechanism: Felbamate causes the level of phenobarbital in your blood to rise.
Drugs that have been shown, or that would be expected, to decrease plasma carbamazepine levels include cisplatin, doxorubicin HCl, felbamate, fosphenytoin, rifampin, phenobarbital, phenytoin, primidone, methsuximide, theophylline, aminophylline.
Mechanism: Felbamate causes your body to process carbamazepine more quickly, which can lead to lower levels of the drug in your system.
Some drugs or herbal products that may decrease the effectiveness of hormonal contraceptives include phenytoin, barbiturates, carbamazepine, bosentan, felbamate, griseofulvin, oxcarbazepine, rifampin, topiramate and products containing St.
Mechanism: Felbamate can cause your body to process birth control hormones faster, which makes the pill less effective at preventing pregnancy.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
Can I start felbamate as the first medicine for my seizures?
What should I do if I experience side effects?
Will I need blood tests while taking felbamate?
Can I take felbamate with other seizure medicines?
How quickly will felbamate start working?
Can I stop taking felbamate suddenly?
Does felbamate interact with other medications?
What happens if I take too much felbamate?
Can I drink alcohol while taking felbamate?
How often will I see my doctor while taking felbamate?
What are the common side effects of felbamate?
Does felbamate interact with other medications?
What drug class is felbamate?
Is there a generic version of felbamate?
What pregnancy or breastfeeding source fields are listed for felbamate?
Related Medications in Anticonvulsant
Other drugs grouped near felbamate - same-class peers and common alternatives.
brivaracetam
Briviact
Brivaracetam is a medicine used to treat partial-onset seizures.
Compare with felbamate →
cannabidiol
Epidiolex
Epidiolex is a medicine that contains cannabidiol.
Compare with felbamate →
carbamazepine
Tegretol
Carbamazepine is a medicine used to control seizures and treat nerve pain.
Compare with felbamate →
cenobamate
Xcopri
Xcopri is a medicine used to treat partial-onset seizures in adults.
Compare with felbamate →
clobazam
Onfi, Sympazan
Clobazam oral suspension is a medicine used with other medicines to treat seizures caused by Lennox-Gastaut syndrome.
Compare with felbamate →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for felbamate: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 1,714.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 5.02%.
- secukinumab Δ 0.09 pts · 157,236 reports · IL-17A Inhibitor (Biologic) 4.93%death share
- empagliflozin Δ 0.10 pts · 61,560 reports · SGLT2 Inhibitor 4.92%death share
- dorzolamide Δ 0.12 pts · 7,422 reports · Carbonic Anhydrase Inhibitor (Ophthalmic) 5.13%death share
- oxytocin Δ 0.12 pts · 2,902 reports · Oxytocic Hormone 5.13%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for felbamate
The FDA label for felbamate (sold under brand names such as Felbatol) classifies it as a prescription-only medication in the Anticonvulsant class. Felbamate treats partial seizures in adults, both with and without generalization. Official labeling lists 7 commonly reported side effects, including Loss of appetite, Vomiting, Trouble sleeping.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 1,714 voluntary reports. The database also lists 16 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $0.82 versus $14.03 for the brand - a 94% generic savings.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: June 21, 2017
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages