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felbamate (Rx)Brand and Other Names:Felbatol

 
 
 

Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablets

  • 400 mg
  • 600 mg

oral suspension

  • 600 mg/5 mL
more...

Seizures

Monotherapy

  • 1200 mg/day PO divided q6-8hr initially; titrate previously untreated patients with caution, increasing the dose in 600 mg increments q2weeks to 2400 mg/day based on clinial response and thereafter to 3600 mg/day if necessary

Conversion to monotherapy

  • Initial: 1200 mg/day PO divided q6-8hr; reduce dose of concomitant anticonvulsant(s) by 33% at initiation of felbamate therapy
  • Week 2: Increase felbamate dose to 2400 mg/day while reducing the dosage of other anticonvulsant(s) up to an additional 33% of original dosage
  • Week 3: Increase felbamate dose up to 3600 mg/day and continue to reduce dosage of other anticonvulsant(s) as clinically indicated

Adjunctive therapy

  • Initial: 1200 mg/day PO divided q6-8hr; increase by 1200 mg/day once per week up to 3600 mg/day PO divided q6-8hr
  • Decrease concomitant dose of carbamazepine, phenytoin, phenobarbital, or valproic acid by 20 % when intiating felbamate dosing; as felbamate dose is increased, further dosage reductions of concomitant anticonvulsant therapies may be necessary

Renal Impairment

Decreased intial and maintenance doses by 50%

Hepatic Impairment

Contraindicated

Dosage Forms & Strengths

tablets

  • 400 mg
  • 600 mg

oral suspension

  • 600 mg/5mL
more...

Seizures

<14 years: Safety and efficacy not established

>14 years:

Monotherapy

  • 1200 mg/day PO divided q6-8hr initially; titrate previously untreated patients with caution, increasing the dose in 600 mg increments q2weeks to 2400 mg/day based on clinial response and thereafter to 3600 mg/day if necessary

Conversion to monotherapy

  • Initial: 1200 mg/day PO divided q6-8hr; reduce dose of concomitant anticonvulsant(s) by 33% at initiation of felbamate therapy
  • Week 2: Increase felbamate dose to 2400 mg/day while reducing the dosage of other anticonvulsant(s) up to an additional 33% of original dosage
  • Week 3: Increase felbamate dose up to 3600 mg/day and continue to reduce dosage of other anticonvulsant(s) as clinically indicated

Adjunctive therapy

  • Initial: 1200 mg/day PO divided q6-8hr; increase by 1200 mg/day once per week up to 3600 mg/day PO divided q6-8hr
  • Decrease concomitant dose of carbamazepine, phenytoin, phenobarbital, or valproic acid by 20 % when intiating felbamate dosing; as felbamate dose is increased, further dosage reductions of concomitant anticonvulsant therapies may be necessary

Lennox-Gastaut Adjunctive Therapy

<2 years

  • Safety and efficacy not established

2-14 years

  • Initial: 15 mg/kg/day PO divided q6-8hr
  • May increase to by 15 mg/kg/day qWeek to 45 mg/kg/day
  • Decrease concomitant dose of carbamazepine, phenytoin, phenobarbital, or valproic acid by 20 % when intiating felbamate dosing; as felbamate dose is increased, further dosage reductions of concomitant anticonvulsant therapies may be necessary
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Interactions

Interaction Checker

felbamate and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            Adverse Effects

            >10%

            Adjunctive therapy

            • Nausea (34.2%)
            • Vomiting (16.7%)
            • Constipation (11.4%)
            • Dyspepsia (12.3%)
            • Anorexia (19.3%)
            • Dyspepsia (12.3%)

            Lennox-Gastaut

            • Anorexia (55%)
            • Somnolence (48%)
            • URI (46-50%)
            • Vomiting (39%)
            • Nervousness (16-20%)
            • Insomnia (16.1%)
            • Purpura (11-15%)
            • Fever (22.6%)
            • Constipation (12.9%)

            1-10%

            Monotherapy

            • Acne (3.4%)
            • Anxiety (5.2%)
            • Constipation (6.9%)
            • Diarrhea (5.2%)
            • Diplopia (3.4%)
            • Dyspepsia (8.6%)
            • Face edema (3.4%)
            • Fatigue (6.9%)
            • Headache (6.9%)
            • Insomnia (8.6%)
            • Intramenstrual bleeding (3.4%)
            • Otitis media (3.4%)
            • Rash (3.4%)
            • Urinary tract infection (3.4%)
            • Vomiting (8.6%)

            Adjunctive therapy

            • Abdominal pain (5.3%)
            • Abnormal gait (5.3%)
            • Anxiety (5.3%)
            • Ataxia (3.5%)
            • Depression (5.3%)
            • Increased ALT (3.5%)
            • Diarrhea (5.3%)
            • Dry mouth (2.6%)
            • Diplopia (6-10%)
            • Paresthesia (3.5%)
            • Pharyngitis (2.6%)
            • Stupor (2.6%)
            • Sinusitis (2-5%)
            • Tremor (6.1%)
            • Upper respiratory infection (5.3%)

            Lennox-Gastaut

            • Abnormal gait (9.7%)
            • Abnormal thoughts (6.5%)
            • Ataxia (6.5%)
            • Dyspepsia (6.5%)
            • Emotional lability (6.5%)
            • Fatigue (9.7%)
            • Headache (6.5%)
            • Hiccup (9.7%)
            • Leukopenia (6.5%)
            • Miosis (6.5%)
            • Nausea (6.5%)
            • Coughing (6.5%)
            • Pain (6.5%)
            • Pharyngitis (9.7%)
            • Otitis media (6-10%)

            <1%

            Atrial arrhythmia

            Bradycardia

            Hypotension

            Thrombophlebitis

            Cerebral edema

            Coma

            Alopecia

            Jaundice

            Hepatic failure

            Rigors

            Rhabdomyolysis

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            Warnings

            Black Box Warnings

            Aplastic anemia associated with felbamate use. Risk 100-fold in felbamate-treated patients compared with untreated population.

            May be fatal. Use only in patients with severe epilepsy in whom risk of aplastic anemia is acceptable.

            Acute liver failure reported with use; initiate use in patients with normal liver function.

            Contraindications

            Hypersensitivity to carbamates; history of blood dyscrasia, hepatic impairment

            Cautions

            Increased risk of suicidal behavior reported with anticonvulsant use; monitor patients for changes in behavior that might indicate suicidal behavior

            Associated with increased incidence of aplastic anemia and acute hepatic failure , use only when alternative therapy is unsuitable and benefits outweigh risks

            Use caution in renal impairment

            Not for use as first line therapy in epilepsy; for use when benefits outweigh risks

            Do not discontinue therapy abruptly

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            Pregnancy & Lactation

            Pregnancy Category: C

            Lactation: Excreted in milk; not recommended

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.

            more...
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            Pharmacology

            Mechanism of Action

            Mechanism of action is unknown. Has weak inhibitory effects on GABA-receptor binding and benzodiazepine receptor binding.

            Pharmacokinetics

            Half-Life: 20-23 hr

            Peak Plasma: 17-49 mcg/mL (dose-dependent)

            Peak serum time: 3-5 hr

            Bioavailability: High

            Protein bound: 22-25%

            Vd: 756 mL/kg

            Metabolism: Liver

            Metabolites: Inactive

            Total body clearance: 26 mL/hr/kg (single dose); 30 mL/hr/kg (mult. doses)

            Excretion: Urine (80-90%)

            Enzyme induced: CYP3A4

            Enzyme inhibited: hepatic CYP2C19

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            Images

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            Formulary

            FormularyPatient Discounts

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            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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