Felbamate (Systemic)


VA CLASSIFICATION
Primary: CN400

Commonly used brand name(s): Felbatol.

Another commonly used name is
FBM . {11} {16} {31} {33}
Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).

Not commercially available in Canada.



Category:


Anticonvulsant —

Indications

Accepted

Epilepsy (treatment)—Felbamate is indicated as monotherapy or as an adjunct to other anticonvulsants for the treatment of partial seizures with or without generalization in adults with severe epilepsy that has not responded to other treatment. {01} {46}

Epilepsy, Lennox-Gastaut syndrome (treatment adjunct)—Felbamate is indicated as adjunctive therapy in the treatment of partial and generalized seizures associated with Lennox-Gastaut syndrome in children who have not responded to other treatment. {01} {46}


Pharmacology/Pharmacokinetics

Physicochemical characteristics:

Chemical group—
    Dicarbamate. {24} {26} {34} {36} Structurally similar to meprobamate {07} {08} {26}.
Molecular weight—
    238.24 {01} {09}

Mechanism of action/Effect:

In vitro receptor binding studies suggest that felbamate may be an antagonist {01} {07} {17} {47} at the strychnine-insensitive {01} {12} {17} {25} {34} {47} glycine-recognition site of the N-methyl-D-aspartate (NMDA) receptor-ionophore complex. {01} {07} {12} {17} {25} {34} {47} Antagonism of the NMDA receptor glycine binding site may block the effects of the excitatory amino acids {07} {17} {34} and suppress seizure activity. {07} Animal studies indicate that felbamate may increase the seizure threshold {01} {04} {07} {11} {12} {34} and may decrease seizure spread. {01} {04} {07} {11} {12} {34}


Other actions/effects:

Animal studies have shown felbamate to induce the cytochrome P-450 enzyme system to some extent. {14} {19} {45} In clinical studies, however, felbamate has acted as an enzyme inhibitor {12}, possibly through competitive inhibition. {14} {15} In rat studies, felbamate has been shown to possess some neuroprotective activity against hypoxic-ischemic damage {07} {12} {17} {34}, probably through interaction with the strychnine-insensitive glycine receptor {17}, at plasma concentrations achieved during clinical use {07} {12} {17} {49}; the relevance to humans is unknown. {07}

Absorption:

Complete (>90%) {07} {08} {12} {36}. Absorption is unaffected by food {07} {08} {12}, and both tablet and suspension dosage forms exhibit similar kinetics. {01} {07} {12} {31}

Distribution:

Felbamate enters the central nervous system (CNS), with a brain/plasma coefficient of approximately 0.9. {34} The apparent volume of distribution (Vol D) ranged from 0.73 to 0.85 L per kg of body weight (L/kg) in single and multiple dose studies. {01} {07} {24} {33} Felbamate is distributed into breast milk. {01}

Protein binding:

Low {06} {07} (20-36%). {01} {07} {08} {14} {15} {19} {36}

Biotransformation:

Hepatic {06} {08} {34}, probably by the cytochrome P-450 system {07} {14}; primarily by hydroxylation {06} {14} {34} and conjugation {06} {34} to metabolites that are neither pharmacologically active {06} {07} {08} {24} {34} {35} nor neurotoxic. {24} {34} {35}

Half-life:

Elimination—13 to 23 hours. {01} {05} {06} {07} {08} {24} {29} {32} {34} {36}

Time to peak concentration:

1 to 6 hours. {06} {07} {08} {24} {29} {34} {36}

Therapeutic serum concentration

The therapeutic concentration range for felbamate has yet to be established. {12} {33} Plasma concentrations in 21 patients receiving monotherapy with 3600 mg of felbamate per day ranged from 23.7 to 136.6 mcg per mL (mcg/mL) {03} (99.5 to 573.7 micromoles per L [micromoles/L]), with a mean of 78.4 mcg/mL {03} {12} (329.3 micromoles/L).

Elimination:
    Renal—About 90% of an orally administered radioactive dose of felbamate was recovered in the urine, {01} {07} {12} {32} {33} 40 to 50% of which was recovered unchanged. {01} {07} {12} {24} {32} {33}
    Fecal—Less than 5% {07} {32} of an orally administered radioactive dose of felbamate was recovered in the feces.


Precautions to Consider

Cross-sensitivity and/or related problems

Patients sensitive to other carbamate derivatives (for example, carbromal, carisoprodol, meprobamate, mebutamate, or tybamate) may also be sensitive to felbamate. Felbamate should be used cautiously in patients who have demonstrated hypersensitivity reactions to other carbamate derivatives. {01} {36}

Carcinogenicity/Tumorigenicity

In lifetime carcinogenicity studies, rats and mice received dosages of felbamate that resulted in steady state plasma concentrations less than or equal to those of humans receiving 3600 mg per day. {01} The mice and the female rats showed a significant increase in hepatic cell adenomas, the mice showed a significant increase in hepatic hypertrophy, and the male rats showed a significant increase in benign interstitial cell tumors of the testes. {01} The significance to humans is unknown. {01}

As a result of the manufacturing process of felbamate, small amounts of two known animal carcinogens, ethyl carbamate (urethane) and methyl carbamate, may be present in the final dosage forms. {01} The amounts present in felbamate used in lifetime carcinogenic studies were inadequate to cause tumors in rats and mice. {01} A patient receiving 3600 mg per day of felbamate could be exposed to up to 0.72 mcg of urethane and 1800 mcg of methyl carbamate per day. {01} These amounts are 1/10,000 and 1/1,600, respectively, of the dose levels shown to be carcinogenic in rodents, on a mg per square meter of body surface area (mg/m 2) basis. {01}

Mutagenicity

No evidence of mutagenesis was revealed in microbial and mammalian cell assays. {01}

Pregnancy/Reproduction
Fertility—
No effect on male or female fertility was seen in rats at oral doses up to 3 times the human maximum daily dose on a mg/m 2 basis. {01}

Pregnancy—
Studies in humans have not been done. {01} {34}

Felbamate crosses the placenta in rats. {01} {12} Incidence of malformation in offspring was not increased in rats at doses up to 3 times, or in rabbits at doses less than 2 times, the human maximum daily dose on a mg/m 2 basis. {01} However, rat pup weight was decreased, and pup mortality during lactation was increased. {01} The cause of these deaths is unknown. {01} No effect was seen in rats given 1.5 times the human maximum daily dose of felbamate on a mg/m 2 basis. {01}

FDA Pregnancy Category C. {01}


Labor and delivery—

The effect of felbamate on labor and delivery is not known. {01}

Breast-feeding

Felbamate is distributed into breast milk. {01} However, the effect on the nursing infant is unknown. {01}

Pediatrics

Felbamate has been associated with several deaths due to aplastic anemia and acute liver failure. It is not known whether children are at increased risk for developing these adverse effects. However, children may be less able than adults to articulate symptoms should these effects occur. Felbamate should be used in children only if other medications have failed to control seizures. {48}


Geriatrics


Although appropriate studies on the relationship of age to the effects of felbamate have not been performed in the geriatric population, {01} no geriatrics-specific problems have been documented to date. However, elderly patients are more likely to have age-related renal function impairment and other concomitant diseases, and to use other medications, which may require more cautious dosing of felbamate. {01}

Drug interactions and/or related problems
The following drug interactions and/or related problems have been selected on the basis of their potential clinical significance (possible mechanism in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):


Note: Possible interactions with hepatic enzyme inducers, hepatic enzyme inhibitors, and medications that are metabolized by the hepatic P-450 enzyme system, other than those listed below, have not been studied, but the possibility of a significant interaction should be considered and the patient should be carefully monitored during and following concurrent use.

» Carbamazepine    (enzyme induction by carbamazepine {07} may lead to decreased felbamate plasma concentrations {01} {06} {07} {08} {12} {33} {35} {36}; increased felbamate plasma concentrations may occur when carbamazepine dosage is reduced or carbamazepine is discontinued {07}; concurrent use may also decrease carbamazepine plasma concentrations {01} {06} {07} {08} {09} {14} {15} {16} {26} {35} by about 20 to 30% {05} {06} {07} {08} {12} {16} {19} {23} {30} {36} and may increase the plasma concentrations of carbamazepine-10,11-epoxide, {01} {06} {07} {08} {12} {16} {19} {30} {33} {35} an active metabolite of carbamazepine {19}, by about 60% {01} {08} {23} {30} {34} {36} , leading to an increase in adverse effects {03} {19} {34}; carbamazepine dosage should be reduced {01} {07} {08} {33} {35} by 20 to 33% {01} when felbamate therapy is initiated, and plasma concentrations of carbamazepine should be monitored, {15} {19} {40} with further dosage adjustments made as clinically necessary {01} {07} {33})


Methsuximide    (felbamate may increase plasma concentrations of N-desmethylmethsuximide {07} {22}, an active metabolite of methsuximide {18} {27}, leading to increased adverse effects {07} {22}; methsuximide dosage should be reduced by 20 to 33% {01} {37} when felbamate therapy is initiated, with further dosage adjustments made as clinically necessary {01})


Phenobarbital
(felbamate may increase phenobarbital plasma concentrations, leading to increased adverse effects{39} ; phenobarbital dosage should be reduced by 20 to 33% when felbamate therapy is initiated{40} , and plasma phenobarbital concentrations should be monitored{40} , with further dosage adjustments made as clinically necessary){39}
» Phenytoin    (enzyme induction by phenytoin {07} may lead to decreased felbamate plasma concentrations {01} {05} {06} {07} {08} {12} {20} {33} {35} {36} during concurrent use; increased felbamate plasma concentrations may occur when phenytoin dosage is reduced or phenytoin is discontinued {07}; since both felbamate and phenytoin are hydroxylated by the cytochrome P-450 system, {07} {14} possible competitive inhibition of phenytoin metabolism {05} {07} {12} {14} {15} {35} {36} may result in phenytoin plasma concentrations being increased {01} {05} {06} {07} {08} {12} {14} {15} {26} {33} {35} {36} by 20 to 40%, {06} {09} {21} {27} {34} leading to increased adverse effects {03} {07}; phenytoin dosage should be reduced {01} {07} {08} {15} {33} {35} by 20 to 33% {01} when felbamate therapy is initiated, and plasma concentrations of phenytoin should be monitored, {07} {15} {40} with further dosage adjustments made as necessary {01} {05} {07} {12} {15} {21} {33} {36} to maintain therapeutic plasma concentrations {01} {05} {07} {12} and limit adverse effects {01} {02} {05})


» Valproic acid    (felbamate may increase valproic acid plasma concentrations {01} {06} {07} {08} {12} {26} {33} {34} {35} {36} by approximately 20 to 40%, {06} {34} leading to increased adverse effects {07} {29}; valproic acid dosage should be reduced {01} {07} {29} {33} by 20 to 33% {01} when felbamate therapy is initiated, and plasma concentrations of valproic acid should be monitored, {07} {40} with further dosage adjustments made as clinically necessary {01} {07} {12} {33})


Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).


Except under special circumstances, this medication should not be used when the following medical problems exist:
» Blood disorders characterized by serious abnormalities in blood count, platelets, or serum iron{44} or
» Bone marrow depression, or history of{44} or
» Hepatic function impairment or history of{46}    (condition may be exacerbated {44})


Risk-benefit should be considered when the following medical problems exist
» Hematologic reactions to other medications, history of{44}    (patients may be especially at risk for felbamate-induced bone marrow depression {44})


» Sensitivity to felbamate or other carbamate derivatives{01}

Patient monitoring
The following may be especially important in patient monitoring (other tests may be warranted in some patients, depending on condition; » = major clinical significance):


Note: Monitoring may not detect aplastic anemia or liver failure before serious illness has developed; however, early detection of these life-threatening adverse effects may facilitate optimal treatment. {48}

» Hepatic function determinations    (ALT [SGPT], AST [SGOT], and serum bilirubin determinations are recommended prior to initiation of felbamate treatment, and regularly thereafter. Felbamate should be discontinued immediately if any indication of liver injury develops {46})


» Blood counts, complete (CBCs), including platelet and possibly reticulocyte counts{44} and
» Iron concentrations, serum{44}    (determinations recommended prior to initiation of therapy as a baseline. Patients who develop low or decreased white blood cell or platelet counts during the course of treatment should be monitored closely and felbamate discontinued if there is any evidence of significant bone marrow depression {44})




Side/Adverse Effects

Note: There have been reports of deaths due to both aplastic anemia {42} {44} and acute liver failure {46} associated with felbamate use. However, causal relationships have not been definitively established. Appropriate monitoring, including complete blood cell counts, {44} determinations of serum iron concentrations, {44} and liver function tests, {46} should be conducted.
In clinical trials, the frequency of adverse effects was much lower during felbamate monotherapy than during polytherapy with other anticonvulsant medications. {02} {03} {06} {07} {08} {09} {12} {26} {28} {33} {34} {36} The adverse effects seen most frequently during felbamate monotherapy were anorexia, {01} {02} {03} {12} headache, {01} {12} insomnia, {01} {02} {03} and weight loss. {09} {12}

The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:

Those indicating need for medical attention
Incidence more frequent
    
Fever{01}{04}{07}{08}
    
gait abnormality{01}{04}{07}{28} (walking in unusual manner)
    
purpura{01}{04}{07} (purple or red spots on skin)

Incidence less frequent
    
CNS toxicity, specifically agitation,{01}{08} aggression{01} or other mood or mental changes{01}{07} , ataxia{01}{04}{05}{07}{08}{09}{12}{33}{34} (clumsiness or unsteadiness), or tremor{01}{02}{07} (trembling or shaking)
    
skin rash{01}{02}{06}{07}{08}

Incidence rare
    
Anaphylactoid reaction{01} (nasal congestion; shortness of breath or troubled breathing; skin rash, hives or itching; swelling of face)
    
blood dyscrasias, including agranulocytosis{01}{08} (chills; fever; sore throat; general feeling of tiredness or weakness), aplastic anemia{42}{44} (shortness of breath, troubled breathing, wheezing, or tightness in chest; sores, ulcers, or white spots on lips or in mouth; swollen or painful glands; unusual bleeding or bruising), leukopenia{01}{04}{08} (chills; fever; sore throat), pancytopenia{44} (nosebleeds or other unusual bleeding or bruising), thrombocytopenia{44} (unusual bleeding or bruising; black, tarry stools; blood in urine or stools; pinpoint red spots on skin), or qualitative platelet disorder{01} (unusual bruising or bleeding; black or tarry stools)
    
bone marrow depression{44} (chills; fever; sore throat; unusual bleeding or bruising)
    
liver failure, acute{46} (continuing headache; continuing stomach pain; continuing vomiting; dark-colored urine; general feeling of tiredness or weakness; light-colored stools; yellow eyes or skin)
    
lymphadenopathy{01} (swollen lymph nodes)
    
photosensitivity{01} (sensitivity of skin to sunlight)
    
psychosis{12}{13} (severe mood or mental changes)
    
Stevens-Johnson syndrome{01}{06}{08} (skin rash or itching; sores or white spots on lips or in mouth; sore throat; fever; chills; muscle cramps; pain; weakness; chest pain)


Note: Thrombocytopenia is usually asymptomatic; rarely, symptoms are present.



Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent
    
Dizziness{01}{02}{03}{05}{06}{07}{09}{10}{12}{34}{36}
    
gastrointestinal effects, specifically abdominal pain{01}{02}{03}{07}{12}{13} (stomach pain), anorexia{01}{02}{03}{04}{06}{07}{08}{09}{10}{12}{26}{28}{33}{34}{36} (loss of appetite), constipation{01}{03}{07}{08}{10}
dyspepsia{01}{02}{03}{07}{08}{09}{10} (indigestion), nausea{01}{02}{03}{05}{06}{07}{08}{09}{10}{12}{13}{28}{33}{34}{36} or vomiting{01}{02}{03}{04}{05}{07}{08}{09}{10}{12}{28}{34}{36}
    
headache{01}{02}{03}{05}{06}{07}{08}{09}{10}{12}{33}{36}
    
insomnia{01}{02}{03}{04}{06}{07}{08}{09}{10}{12}{13}{26}{28}{33}{34} (trouble in sleeping)
    
taste perversion{01}{03}{07}{12}{26}{33} (change in sense of taste)

Incidence less frequent
    
Anxiety{01}{10}{12}{13}
    
diarrhea{01}{02}{03}{07}{08}{34}
    
drowsiness{01}{02}{03}{04}{06}{07}{08}{09}{10}{36}
    
nervousness{01}{02}{03}{07}{34}
    
rhinitis{01}{07} (runny nose)
    
upper respiratory tract infection{01}{02}{04} (coughing; ear congestion or pain; fever; head congestion; nasal congestion; runny nose; sneezing; sore throat)
    
vision abnormalities, including blurred vision{01}{05}{07}{12}{33} and diplopia{01}{02}{05}{09}{36} (double vision)
    
weight loss{01}{02}{03}{07}{08}{09}{12}{13}{28}{33}{34}





Overdose
For information on the management of overdose or unintentional ingestion, contact a Poison Control Center (see Poison Control Center Listing ).

Clinical effects of overdose
Experience with felbamate overdose is limited. One patient who ingested 12 grams of felbamate over 12 hours experienced mild gastric distress and a resting heart rate of 100 beats per minute. {01}

Treatment of overdose
There is no specific antidote for felbamate overdose. Recommended treatment includes:

To decrease absorption—Emesis or gastric lavage {41}.

Supportive care {01}—Patients in whom intentional overdose is confirmed or suspected should be referred for psychiatric consultation.


Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Felbamate (Systemic).

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):

Before using this medication
»   Conditions affecting use, especially:
Sensitivity to felbamate or to other carbamate derivatives {01}

Pregnancy—Crosses the placenta in rats. {01} Animal studies using up to 3 times the maximum human dose in mg/m 2 have shown decreased rat pup weight and decreased survival; {01} clinical significance is unknown {01}





Breast-feeding—Distributed into breast milk





Use in children—Children may be unable to articulate symptoms of aplastic anemia or acute liver failure; use only if other medications have failed to control seizures

Other medications, especially carbamazepine, phenytoin, and valproic acid
Other medical problems, especially blood disorders, bone marrow depression, or hepatic function impairment

Proper use of this medication
» Compliance with therapy; not taking more or less medicine than prescribed

Proper administration for liquid dosage form: Shaking well; using an accurate measuring device, such as a specially marked measuring spoon, a plastic syringe, or a small graduated cup

» Proper dosing
Missed dose: Taking as soon as possible; if almost time for next dose, skipping missed dose and going back to regular dosing schedule; not doubling doses

» Proper storage

Precautions while using this medication
» Regular visits to physician to check progress of therapy and to monitor for severe adverse effects

» Not discontinuing felbamate abruptly; consulting physician about gradually reducing dosage

» Possible dizziness, drowsiness, impairment of judgment, thinking, or motor skills; caution when driving or doing jobs requiring alertness


Side/adverse effects
Fever; gait abnormality; purpura; CNS toxicity, specifically agitation, aggression, or other mood or mental changes, ataxia, tremor; skin rash; anaphylactoid reaction; blood dyscrasias, including agranulocytosis, aplastic anemia, leukopenia, pancytopenia, thrombocytopenia, qualitative platelet disorder; bone marrow depression; liver failure, acute; lymphadenopathy; photosensitivity; psychosis; Stevens-Johnson syndrome


General Dosing Information
Most adverse effects that emerge when adding felbamate to an anticonvulsant regimen resolve as dosages of concomitant anticonvulsant medications are reduced. {01} {02}

Adverse gastrointestinal effects may be reduced by taking felbamate after meals. {34} {40} If nausea persists, felbamate dosage may be decreased {34} {40} until tolerance to the gastrointestinal effects develops. {34} {40}

Neither felbamate nor other anticonvulsant medications should be suddenly discontinued because of the possibility of increased seizure frequency. {01} The dosage should be reduced gradually when an anticonvulsant medication is being withdrawn. {01}

For treatment of adverse effects
Treatment of bone marrow depression includes the following:

   • Discontinuing felbamate therapy. {44}
   • Daily CBC, platelet and reticulocyte counts. {44}
   • Performing a bone marrow aspiration and trephine biopsy immediately and repeating with sufficient frequency to monitor recovery. {44}
   • Considering other studies that may be helpful, including white cell and platelet antibodies; 59Fe—ferrokinetic studies; peripheral blood cell typing; cytogenic studies on marrow and peripheral blood; bone marrow culture studies for colony-forming units; hemoglobin electrophoresis for A 2 and F hemoglobin; and serum folic acid and B 1 2 concentrations. If aplastic anemia develops, specialized consultation should be sought for appropriate monitoring and treatment. {44}


Oral Dosage Forms

FELBAMATE ORAL SUSPENSION

Usual adult and adolescent dose
Anticonvulsant
Oral, initially 1200 mg per day, usually divided into three or four doses, the dosage being gradually increased over several weeks based on clinical response. {01}


Usual adult and adolescent prescribing limits
3600 mg per day. {01} {07} {36}

Usual pediatric dose
Anticonvulsant
Children 2 to 14 years of age: Oral, initially 15 mg per kg of body weight per day, usually divided into three or four doses, the dosage being gradually increased over a few weeks based on clinical response. {01}


Usual pediatric prescribing limits
Children 2 to 14 years of age—45 mg per kg per day or 3600 mg per day, whichever is less. {07} {36}

Strength(s) usually available
U.S.—


600 mg per 5 mL (Rx) [Felbatol (sorbitol) (glycerin) (microcrystalline cellulose) (carboxymethylcellulose sodium) (simethicone) (polysorbate 80) (methylparaben) (saccharin sodium) (propylparaben) (FD&C Yellow No. 6) (FD&C Red No. 40) (flavorings) (purified water{01})]

Canada—
Not commercially available.

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a tight container {01}, unless otherwise specified by manufacturer.

Auxiliary labeling:
   • Shake well before using.
   • May cause dizziness or drowsiness.

Additional information:
Use a specially marked measuring spoon, a plastic syringe, or a small marked measuring cup to measure each dose accurately.


FELBAMATE TABLETS

Usual adult and adolescent dose
See Felbamate Oral Suspension.

Usual adult and adolescent prescribing limits
See Felbamate Oral Suspension.

Usual pediatric dose
See Felbamate Oral Suspension.

Usual pediatric prescribing limits
See Felbamate Oral Suspension.

Strength(s) usually available
U.S.—


400 mg (Rx) [Felbatol (scored) (starch) ( microcrystalline cellulose) (croscarmellose sodium) (lactose) (magnesium stearate) (FD&C Yellow No. 6) (D&C Yellow No. 10{01})]


600 mg (Rx) [Felbatol (scored) (starch) (microcrystalline cellulose) (croscarmellose sodium) (lactose) (magnesium stearate) (FD&C Yellow No. 6) (D&C Yellow No. 10) (FD&C Red No. 40{01})]

Canada—
Not commercially available.

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a tight container, away from moisture, {01} unless otherwise specified by manufacturer.

Auxiliary labeling:
   • May cause dizziness or drowsiness.



Revised: 03/28/1995



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  1. Graves NM, Leppik IE. Advances in pharmacotherapy: recent developments in the treatment of epilepsy. J Clin Pharm Ther 1993; 18: 227-42.
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  1. Personal communication, Wallace Laboratories, 5/4/94.
  1. Personal communication, Wallace Laboratories, 5/11/94.
  1. Gidal BE, Zupanc ML. Potential pharmacokinetic interaction between felbamate and phenobarbital. Ann Pharmacother 1994 Apr; 28: 455-7.
  1. Reviewers' consensus on monograph revision of 6/13/94.
  1. Manufacturers comment, 7/20/94.
  1. Personal communication, Wallace Laboratories, 8/8/94.
  1. Panel comment, 7/94.
  1. Personal communication, Wallace Laboratries, 8/12/94.
  1. Segelman FH, Kelton E, Terzi RM, et al. The comparative potency of phenobarbital and five 1,3-propanediol dicarbamates for hepatic cytochrome P-450 induction in rats. Res Commun Chem Pathol Pharmacol 1985 Jun; 48(3): 467-70.
  1. Wallace Laboratories: Important Drug Warning, 9/21/94.
  1. Wamsley JK, Sofia RD, Faull RLM, et al. Felbamate: Interaction with glycine receptors in human cerebral cortex. Proc West Pharmacol Soc 1994; 37: 81-3.
  1. Pediatrics Advisory Panel Meeting, 10/25/94.
  1. Adusumalli VE, Wichmann JK, Kucharczyk N, et al. Drug concentrations in human brain tissue samples from epileptic patients treated with felbamate. Drug Metab Dispos 1994; 22(1): 168-70.
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