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Medication Guide — Felbatol

Patient-friendly FDA guidance and safety information.

Last updated · May 12, 2026Source: DailyMed ↗
Boxed Warning

1. APLASTIC ANEMIA

THE USE OF FELBATOL® (felbamate) IS ASSOCIATED WITH A MARKED INCREASE IN THE INCIDENCE OF APLASTIC ANEMIA. ACCORDINGLY, FELBATOL® SHOULD ONLY BE USED IN PATIENTS WHOSE EPILEPSY IS SO SEVERE THAT THE RISK OF APLASTIC ANEMIA IS DEEMED ACCEPTABLE IN LIGHT OF THE BENEFITS CONFERRED BY ITS USE (SEE INDICATIONS ). ORDINARILY, A PATIENT SHOULD NOT BE PLACED ON AND/OR CONTINUED ON FELBATOL® WITHOUT CONSIDERATION OF APPROPRIATE EXPERT HEMATOLOGIC CONSULTATION.

AMONG FELBATOL® TREATED PATIENTS, APLASTIC ANEMIA (PANCYTOPENIA IN THE PRESENCE OF A BONE MARROW LARGELY DEPLETED OF HEMATOPOIETIC PRECURSORS) OCCURS AT AN INCIDENCE THAT MAY BE MORE THAN A 100 FOLD GREATER THAN THAT SEEN IN THE UNTREATED POPULATION (I.E., 2 TO 5 PER MILLION PERSONS PER YEAR). THE RISK OF DEATH IN PATIENTS WITH APLASTIC ANEMIA GENERALLY VARIES AS A FUNCTION OF ITS SEVERITY AND ETIOLOGY; CURRENT ESTIMATES OF THE OVERALL CASE FATALITY RATE ARE IN THE RANGE OF 20 TO 30%, BUT RATES AS HIGH AS 70% HAVE BEEN REPORTED IN THE PAST.

THERE ARE TOO FEW FELBATOL® ASSOCIATED CASES, AND TOO LITTLE KNOWN ABOUT THEM TO PROVIDE A RELIABLE ESTIMATE OF THE SYNDROME’S INCIDENCE OR ITS CASE FATALITY RATE OR TO IDENTIFY THE FACTORS, IF ANY, THAT MIGHT CONCEIVABLY BE USED TO PREDICT WHO IS AT GREATER OR LESSER RISK.

IN MANAGING PATIENTS ON FELBATOL®, IT SHOULD BE BORNE IN MIND THAT THE CLINICAL MANIFESTATION OF APLASTIC ANEMIA MAY NOT BE SEEN UNTIL AFTER A PATIENT HAS BEEN ON FELBATOL® FOR SEVERAL MONTHS (E.G., ONSET OF APLASTIC ANEMIA AMONG FELBATOL® EXPOSED PATIENTS FOR WHOM DATA ARE AVAILABLE HAS RANGED FROM 5 TO 30 WEEKS). HOWEVER, THE INJURY TO BONE MARROW STEM CELLS THAT IS HELD TO BE ULTIMATELY RESPONSIBLE FOR THE ANEMIA MAY OCCUR WEEKS TO MONTHS EARLIER. ACCORDINGLY, PATIENTS WHO ARE DISCONTINUED FROM FELBATOL® REMAIN AT RISK FOR DEVELOPING ANEMIA FOR A VARIABLE, AND UNKNOWN, PERIOD AFTERWARDS.

IT IS NOT KNOWN WHETHER OR NOT THE RISK OF DEVELOPING APLASTIC ANEMIA CHANGES WITH DURATION OF EXPOSURE. CONSEQUENTLY, IT IS NOT SAFE TO ASSUME THAT A PATIENT WHO HAS BEEN ON FELBATOL® WITHOUT SIGNS OF HEMATOLOGIC ABNORMALITY FOR LONG PERIODS OF TIME IS WITHOUT RISK.

IT IS NOT KNOWN WHETHER OR NOT THE DOSE OF FELBATOL® AFFECTS THE INCIDENCE OF APLASTIC ANEMIA.

IT IS NOT KNOWN WHETHER OR NOT CONCOMITANT USE OF ANTIEPILEPTIC DRUGS AND/OR OTHER DRUGS AFFECTS THE INCIDENCE OF APLASTIC ANEMIA.

APLASTIC ANEMIA TYPICALLY DEVELOPS WITHOUT PREMONITORY CLINICAL OR LABORATORY SIGNS, THE FULL BLOWN SYNDROME PRESENTING WITH SIGNS OF INFECTION, BLEEDING, OR ANEMIA. ACCORDINGLY, ROUTINE BLOOD TESTING CANNOT BE RELIABLY USED TO REDUCE THE INCIDENCE OF APLASTIC ANEMIA, BUT, IT WILL, IN SOME CASES, ALLOW THE DETECTION OF THE HEMATOLOGIC CHANGES BEFORE THE SYNDROME DECLARES ITSELF CLINICALLY. FELBATOL® SHOULD BE DISCONTINUED IF ANY EVIDENCE OF BONE MARROW DEPRESSION OCCURS.

2. HEPATIC FAILURE

EVALUATION OF POSTMARKETING EXPERIENCE SUGGESTS THAT ACUTE LIVER FAILURE IS ASSOCIATED WITH THE USE OF FELBATOL®. THE REPORTED RATE IN THE U.S. HAS BEEN ABOUT 6 CASES OF LIVER FAILURE LEADING TO DEATH OR TRANSPLANT PER 75,000 PATIENT YEARS OF USE. THIS RATE IS AN UNDERESTIMATE BECAUSE OF UNDER REPORTING, AND THE TRUE RATE COULD BE CONSIDERABLY GREATER THAN THIS. FOR EXAMPLE, IF THE REPORTING RATE IS 10%, THE TRUE RATE WOULD BE ONE CASE PER 1,250 PATIENT YEARS OF USE.

OF THE CASES REPORTED, ABOUT 67% RESULTED IN DEATH OR LIVER TRANSPLANTATION, USUALLY WITHIN 5 WEEKS OF THE ONSET OF SIGNS AND SYMPTOMS OF LIVER FAILURE. THE EARLIEST ONSET OF SEVERE HEPATIC DYSFUNCTION FOLLOWED SUBSEQUENTLY BY LIVER FAILURE WAS 3 WEEKS AFTER INITIATION OF FELBATOL®. ALTHOUGH SOME REPORTS DESCRIBED DARK URINE AND NONSPECIFIC PRODROMAL SYMPTOMS (E.G., ANOREXIA, MALAISE, AND GASTROINTESTINAL SYMPTOMS), IN OTHER REPORTS IT WAS NOT CLEAR IF ANY PRODROMAL SYMPTOMS PRECEDED THE ONSET OF JAUNDICE.

IT IS NOT KNOWN WHETHER OR NOT THE RISK OF DEVELOPING HEPATIC FAILURE CHANGES WITH DURATION OF EXPOSURE.

IT IS NOT KNOWN WHETHER OR NOT THE DOSAGE OF FELBATOL® AFFECTS THE INCIDENCE OF HEPATIC FAILURE.

IT IS NOT KNOWN WHETHER CONCOMITANT USE OF OTHER ANTIEPILEPTIC DRUGS AND/OR OTHER DRUGS AFFECT THE INCIDENCE OF HEPATIC FAILURE.

FELBATOL® SHOULD NOT BE PRESCRIBED FOR ANYONE WITH A HISTORY OF HEPATIC DYSFUNCTION.

TREATMENT WITH FELBATOL® SHOULD BE INITIATED ONLY IN INDIVIDUALS WITHOUT ACTIVE LIVER DISEASE AND WITH NORMAL BASELINE SERUM TRANSAMINASES. IT HAS NOT BEEN PROVED THAT PERIODIC SERUM TRANSAMINASE TESTING WILL PREVENT SERIOUS INJURY BUT IT IS GENERALLY BELIEVED THAT EARLY DETECTION OF DRUG-INDUCED HEPATIC INJURY ALONG WITH IMMEDIATE WITHDRAWAL OF THE SUSPECT DRUG ENHANCES THE LIKELIHOOD FOR RECOVERY. THERE IS NO INFORMATION AVAILABLE THAT DOCUMENTS HOW RAPIDLY PATIENTS CAN PROGRESS FROM NORMAL LIVER FUNCTION TO LIVER FAILURE, BUT OTHER DRUGS KNOWN TO BE HEPATOTOXINS CAN CAUSE LIVER FAILURE RAPIDLY (E.G., FROM NORMAL ENZYMES TO LIVER FAILURE IN 2-4 WEEKS). ACCORDINGLY, MONITORING OF SERUM TRANSAMINASE LEVELS (AST AND ALT) IS RECOMMENDED AT BASELINE AND PERIODICALLY THEREAFTER. WHILE THE MORE FREQUENT THE MONITORING THE GREATER THE CHANCES OF EARLY DETECTION, THE PRECISE SCHEDULE FOR MONITORING IS A MATTER OF CLINICAL JUDGEMENT.

FELBATOL® SHOULD BE DISCONTINUED IF EITHER SERUM AST OR SERUM ALT LEVELS BECOME INCREASED ≥ 2 TIMES THE UPPER LIMIT OF NORMAL, OR IF CLINICAL SIGNS AND SYMPTOMS SUGGEST LIVER FAILURE (SEE PRECAUTIONS). PATIENTS WHO DEVELOP EVIDENCE OF HEPATOCELLULAR INJURY WHILE ON FELBATOL® AND ARE WITHDRAWN FROM THE DRUG FOR ANY REASON SHOULD BE PRESUMED TO BE AT INCREASED RISK FOR LIVER INJURY IF FELBATOL® IS REINTRODUCED. ACCORDINGLY, SUCH PATIENTS SHOULD NOT BE CONSIDERED FOR RE-TREATMENT.

Poison Help

If you suspect an overdose or accidental ingestion, call Poison Control: 1-800-222-1222 (free, 24/7, U.S.). For life-threatening symptoms, call 911.

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Medication Guide

This Medication Guide has been approved by the U.S. Food and Drug Administration.

FELBATOL (Fel-ba-taal) (felbamate)

Tablets and Oral Suspension

Read this Medication Guide before you start taking FELBATOL and each time you get a refill. There may be new information. This information does not take the place of talking to your healthcare provider about your medical condition or treatment.

What is the most important information I should know about FELBATOL?

Do not stop taking FELBATOL without first talking to your healthcare provider.

Stopping FELBATOL suddenly can cause serious problems.

FELBATOL can cause serious side effects, including:

1. FELBATOL may cause serious blood problems that may be life-threatening.

Call your healthcare provider right away if you have any of the following symptoms:

  • •Fever, sore throat or other infections that come and go or do not go away
  • •Frequent infections or an infection that does not go away
  • •Easy bruising
  • •Red or purple spots on your body
  • •Bleeding gums or nose bleeds
  • •Severe fatigue or weakness

2. Liver problems that may be life-threatening. Call your healthcare provider right away if you have any of these symptoms:

  • •yellowing of your skin or the whites of your eyes (jaundice)
  • •dark urine
  • •nausea or vomiting
  • •loss of appetite
  • •pain on the right side of your stomach (abdomen)

3. Like other antiepileptic drugs, FELBATOL may cause suicidal thoughts or actions in a very small number of people, about 1 in 500.

Call your healthcare provider right away if you have any of these symptoms, especially if they are new, worse, or worry you:

  • •thoughts about suicide or dying
  • •new or worse depression
  • •attempts to commit suicide
  • •feeling agitated or restless
  • •new or worse anxiety
  • •trouble sleeping (insomnia)
  • •panic attacks
  • •acting aggressive, being angry, or violent
  • •new or worse irritability
  • •acting on dangerous impulses
  • •an extreme increase in activity and talking (mania)
  • •other unusual changes in behavior or mood

How can I watch for early symptoms of suicidal thoughts and actions?

  • •Pay attention to any changes, especially sudden changes, in mood, behaviors, thoughts, or feelings.
  • •Keep all follow-up visits with your healthcare provider as scheduled.

Call your healthcare provider between visits as needed, especially if you are worried about symptoms.

Do not stop FELBATOL without first talking to a healthcare provider.

Stopping FELBATOL suddenly can cause serious problems. You should talk to your healthcare provider before stopping. Stopping a seizure medicine suddenly in a patient who has epilepsy can cause seizures.

Suicidal thoughts or actions can be caused by things other than medicines. If you have suicidal thoughts or actions, your healthcare provider may check for other causes.

What is FELBATOL?

FELBATOL is a prescription medicine used when other treatments have failed in:

  • •adults alone or with other medicines to treat:
    • ▪partial seizures with and without generalization
  • •children with other medicines to treat:
    • ▪seizures associated with Lennox-Gastaut syndrome

Who should not take FELBATOL?

Do not take FELBATOL if you:

See the end of this Medication Guide for a complete list of ingredients in FELBATOL.

  • •have or have had blood problems
  • •have or have had liver problems

What should I tell my healthcare provider before taking FELBATOL?

Before you take FELBATOL, tell your healthcare provider if you:

  • •have kidney problems
  • •have or have had depression, mood problems, or suicidal thoughts or behavior
  • •have any other medical conditions
  • •are pregnant or plan to become pregnant. It is not known if FELBATOL can harm your unborn baby. Tell your healthcare provider right away if you become pregnant while taking FELBATOL. You and your healthcare provider will decide if you should take FELBATOL while you are pregnant.
    • ▪If you become pregnant while taking FELBATOL, talk to your healthcare provider about registering with the North American Antiepileptic Drug (NAAED) Pregnancy Registry. The purpose of this registry is to collect information about the safety of antiepileptic medicine during pregnancy. You can enroll in this registry by calling 1-888-233-2334.
  • •are breastfeeding or plan to breastfeed. FELBATOL may pass into your breast milk. You and your healthcare provider should decide if you should take FELBATOL while you breastfeed.

Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.

Taking FELBATOL with certain other medicines can cause side effects or affect how well they work. Do not start or stop other medicines without talking to your healthcare provider.

Know the medicines you take. Keep a list of them and show it to your healthcare provider and pharmacist when you get a new medicine.

How should I take FELBATOL?

  • •Take FELBATOL exactly as your healthcare provider tells you. Your healthcare provider will tell you how much FELBATOL to take and when to take it.
  • •Your healthcare provider may change your dose of FELBATOL. Do not change your dose of FELBATOL without talking to your healthcare provider.
  • •Because of the risk of serious blood and liver problems, your healthcare provider may do blood tests before you start and while you take FELBATOL.
  • •If you take too much FELBATOL, call your healthcare provider or local Poison Control Center right away.
  • •Do not stop FELBATOL without first talking to your healthcare provider.

What should I avoid while taking FELBATOL?

  • •FELBATOL can cause drowsiness and dizziness. Do not drink alcohol or take other medicines that make you sleepy or dizzy while taking FELBATOL, until you talk with your doctor. Taking FELBATOL with alcohol or drugs that cause sleepiness or dizziness may make your sleepiness or dizziness worse.

What are the possible side effects of FELBATOL?

See “What is the most important information I should know about FELBATOL?”

FELBATOL may cause serious side effects including:

The most common side effects of FELBATOL include:

  • •weight loss
  • •trouble sleeping
  • •sleepiness
  • •vomiting
  • •nausea
  • •headache
  • •changes in the way that food tastes
  • •dizziness
  • •double-vision

These are not all the possible side effects of FELBATOL. For more information, ask your healthcare provider or pharmacist.

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

How should I store FELBATOL?

  • •Store FELBATOL at room temperature between 68°F to 77°F (20°C to 25°C).

Keep FELBATOL and all medicines out of the reach of children.

General information about FELBATOL.

Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use FELBATOL for a condition for which it was not prescribed. Do not give FELBATOL to other people, even if they have the same symptoms that you have. It may harm them.

This Medication Guide summarizes the most important information about FELBATOL. If you would like more information, talk with your healthcare provider. You can ask your pharmacist or healthcare provider for information about FELBATOL that is written for health professionals.

What are the ingredients in FELBATOL?

Active Ingredient: felbamate

Tablet Inactive Ingredients: starch, microcrystalline cellulose, croscarmellose sodium, lactose, magnesium stearate, FD&C Yellow No. 6, D&C Yellow No. 10, and FD&C Red No. 40 (600 mg tablets only).

Suspension Inactive Ingredients: sorbitol, glycerin, microcrystalline cellulose, carboxymethylcellulose sodium, simethicone, polysorbate 80, methylparaben, saccharin sodium, propylparaben, FD&C Yellow No. 6, FD&C Red No. 40, flavorings, and purified water.

For more information, call Viatris at 1-877-446-3679 (1-877-4-INFO-RX).

FELBATOL is a registered trademark of Meda Pharmaceuticals Inc., a Viatris Company.

© 2025 Viatris Inc.

Distributed by:
Viatris Specialty LLC
Morgantown, WV 26505 U.S.A.

Rx Only
Revised: 8/2025

VS:SOV:MG:FELT:R1m

Sources

RxCUI: 198358

NDC: 0037-0430

Last fetched: May 12, 2026

Source: DailyMed ↗

⚠️ Disclaimer

This information is for educational purposes only and is not medical advice. Always consult your doctor, pharmacist, or other licensed healthcare professional before starting, stopping, or changing any medicine. Read full medical disclaimer.