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 →
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.
How to Take It
Take felbamate exactly as your doctor tells you. It is usually taken 3 or 4 times a day. If you have kidney problems, your doctor may prescribe a lower dose. Your doctor may also adjust the doses of other seizure medicines you are taking to avoid side effects.
This is a plain-language summary of felbamate's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
It is not known if felbamate can harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if felbamate passes into breast milk, so talk to your doctor if you are breastfeeding.
This is a plain-language summary of felbamate's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is close to your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of felbamate's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store felbamate oral suspension at room temperature, between 68° to 77°F (20° to 25°C), in a tightly closed container.
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
- Sleepiness 108
Sleepiness
108 reports
- Condition getting worse 92
Condition getting worse
92 reports
- Tiredness 85
Tiredness
85 reports
- Medicine interaction 71
Medicine interaction
71 reports
- Harmful effect from different substances 71
Harmful effect from different substances
71 reports
- Throwing up 70
Throwing up
70 reports
- Fall 60
Fall
60 reports
- A type of seizure involving the whole body 60
A type of seizure involving the whole body
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) 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.
What to do: These medications can be used together because they do not have a significant interaction.
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.
What to do: You can take these two drugs together without needing to change your felbamate dose.
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.
What to do: Your doctor may need to lower your phenobarbital dose and monitor your blood levels closely.
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.
What to do: Your doctor may need to monitor your blood levels or adjust your dose of carbamazepine.
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.
What to do: You should use an extra form of birth control, such as condoms, while taking these medicines together.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
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?
Is felbamate safe during pregnancy?
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 →
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
Why some drugs demand precise dosing and monitoring
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 further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
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. Always consult a healthcare professional before making medication decisions.
Last updated: June 21, 2017
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 and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
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