Loading…
Felbamate is a brand name for Felbamate. The medicine, its uses, side effects and dosage are the same regardless of brand.
Used for: INDICATIONS AND USAGE Felbamate oral suspension, USP is not indicated as a first line antiepileptic treatment (see Warnings ). Felbamate oral suspension is recommended for use only in those patients who respond inadequately to alternative treatments and whose epilepsy is so severe that a substantial risk of aplastic…
Verbatim from this product's FDA label. Tap a section to expand.
DOSAGE AND ADMINISTRATION
Felbamate has been studied as monotherapy and adjunctive therapy in adults and as adjunctive therapy in children with seizures associated with Lennox-Gastaut syndrome. As felbamate is added to or substituted for existing AEDs, it is strongly recommended to reduce the dosage of those AEDs in the range of 20 to 33% to minimize side effects (see Drug Interactions subsection).
Dosage Adjustment in the Renally Impaired Felbamate should be used with caution in patients with renal dysfunction. In the renally impaired, starting and maintenance doses should be reduced by one-half (see CLINICAL PHARMACOLOGY / Pharmacokinetics and PRECAUTIONS ).
Adjunctive therapy with medications which affect felbamate plasma concentrations, especially AEDs, may warrant further reductions in felbamate daily doses in patients with renal dysfunction. Adults (14 years of age and over) The majority of patients received 3600 mg/day in clinical trials evaluating its use as both monotherapy and adjunctive therapy.
Monotherapy (Initial therapy) felbamate has not been systematically evaluated as initial monotherapy. Initiate felbamate at 1200 mg/day in divided doses three or four times daily. The prescriber is advised to titrate previously untreated patients under close clinical supervision, increasing the dosage in 600-mg increments every 2 weeks to 2400 mg/day based on clinical response and thereafter to 3600 mg/day if clinically indicated.
Conversion to Monotherapy Initiate felbamate at 1200 mg/day in divided doses three or four times daily. Reduce the dosage of concomitant AEDs by one-third at initiation of felbamate therapy. At week 2, increase the felbamate dosage to 2400 mg/day while reducing the dosage of other AEDs up to an additional one-third of their original dosage.
At week 3, increase the felbamate dosage up to 3600 mg/day and continue to reduce the dosage of other AEDs as clinically indicated. Adjunctive Therapy Felbamate should be added at 1200 mg/day in divided doses three or four times daily while reducing present AEDs by 20% in order to control plasma concentrations of concurrent phenytoin, valproic acid, phenobarbital, and carbamazepine and its metabolites.
Further reductions of the concomitant AEDs dosage may be necessary to minimize side effects due to drug interactions. Increase the dosage of felbamate by 1200 mg/day increments at weekly intervals to 3600 mg/day. Most side effects seen during felbamate adjunctive therapy resolve as the dosage of concomitant AEDs is decreased.
ADVERSE REACTIONS
gov/medwatch. The most common adverse reactions seen in association with felbamate in adults during monotherapy are anorexia, vomiting, insomnia, nausea, and headache. The most common adverse reactions seen in association with felbamate in adults during adjunctive therapy are anorexia, vomiting, insomnia, nausea, dizziness, somnolence, and headache.
The most common adverse reactions seen in association with felbamate in children during adjunctive therapy are anorexia, vomiting, insomnia, headache, and somnolence. The dropout rate because of adverse experiences or intercurrent illnesses among adult felbamate patients was 12 percent (120/977).
The dropout rate because of adverse experiences or intercurrent illnesses among pediatric felbamate patients was six percent (22/357). 5%). 1%), and whole body (1%). 1%). 1%). Incidence in Clinical Trials The prescriber should be aware that the figures cited in the following table cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those which prevailed in the clinical trials.
Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different investigators, treatments, and uses including the use of felbamate as adjunctive therapy where the incidence of adverse events may be higher due to drug interactions.
The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the side effect incidence rate in the population studied. Adults Incidence in Controlled Clinical Trials--Monotherapy Studies in Adults The table that follows enumerates adverse events that occurred at an incidence of 2% or more among 58 adult patients who received felbamate monotherapy at dosages of 3600 mg/day in double-blind controlled trials.
WARNINGS
See Boxed Warning regarding aplastic anemia and hepatic failure. Antiepileptic drugs should not be suddenly discontinued because of the possibility of increasing seizure frequency. Suicidal Behavior and Ideation Antiepileptic drugs (AEDs) including felbamate oral suspension, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication.
Patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior. 7) of suicidal thinking or behavior compared to patients randomized to placebo.
24% among 16,029 placebo-treated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide.
The increased risk of suicidal thoughts or behavior with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed.
The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication.
The risk did not vary substantially by age (5 to 100 years) in the clinical trials analyzed. Table 1 shows absolute and relative risk by indication for all evaluated AEDs. 9 The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications.
CONTRAINDICATIONS
Felbamate oral suspension, USP is contraindicated in patients with known hypersensitivity to felbamate oral suspension, its ingredients, or known sensitivity to other carbamates. It should not be used in patients with a history of any blood dyscrasia or hepatic dysfunction.
Not medical advice. Always read the patient information leaflet and follow your prescriber or pharmacist.
Know a brand we are missing in United States of America? Suggest a brand →
Brand names are compiled from public regulatory records for active-ingredient mapping only. Drugvu is not affiliated with any manufacturer. This is not medical advice.
Table 6 Dosage Table (adults) WEEK 1 WEEK 2 WEEK 3 Dosage reduction of concomitant AEDs REDUCE original dose by 20 to 33% See Adjunctive and Conversion to Monotherapy sections. REDUCE original dose by up to an additional 1/3 REDUCE as clinically indicated Felbamate Dosage 1200 mg/day Initial dose 2400 mg/day Therapeutic dosage range 3600 mg/day Therapeutic dosage range While the above felbamate conversion guidelines may result in a felbamate 3600 mg/day dose within 3 weeks, in some patients titration to a 3600 mg/day felbamate dose has been achieved in as little as 3 days with appropriate adjustment of other AEDs.
Children with Lennox-Gastaut Syndrome (Ages 2 to 14 years) Adjunctive Therapy Felbamate should be added at 15 mg/kg/day in divided doses three or four times daily while reducing present AEDs by 20% in order to control plasma levels of concurrent phenytoin, valproic acid, phenobarbital, and carbamazepine and its metabolites.
Further reductions of the concomitant AEDs dosage may be necessary to minimize side effects due to drug interactions. Increase the dosage of felbamate by 15 mg/kg/day increments at weekly intervals to 45 mg/kg/day. Most side effects seen during felbamate adjunctive therapy resolve as the dosage of concomitant AEDs is decreased.
Table 3 presents reported adverse events that were classified using standard WHO-based dictionary terminology. 4 2 Incidence in Controlled Add-On Clinical Studies in Adults Table 4 enumerates adverse events that occurred at an incidence of 2% or more among 114 adult patients who received felbamate adjunctive therapy in add-on controlled trials at dosages up to 3600 mg/day.
Reported adverse events were classified using standard WHO-based dictionary terminology. Many adverse experiences that occurred during adjunctive therapy may be a result of drug interactions. Adverse experiences during adjunctive therapy typically resolved with conversion to monotherapy, or with adjustment of the dosage of other antiepileptic drugs.
3 Children Incidence in a Controlled Add-On Trial in Children with Lennox-Gastaut Syndrome Table 5 enumerates adverse events that occurred more than once among 31 pediatric patients who received felbamate up to 45 mg/kg/day or a maximum of 3600 mg/day.
Reported adverse events were classified using standard WHO-based dictionary terminology. 7 0 Other Events Observed in Association with the Administration of Felbamate In the paragraphs that follow, the adverse clinical events, other than those in the preceding tables, that occurred in a total of 977 adults and 357 children exposed to felbamate and that are reasonably associated with its use are presented.
They are listed in order of decreasing frequency. Because the reports cite events observed in open-label and uncontrolled studies, the role of felbamate in their causation cannot be reliably determined. Events are classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse events are defined as those occurring on one or more occasions in at least 1/100 patients; infrequent adverse events are those occurring in 1/100 to 1/1000 patients; and rare events are those occurring in fewer than 1/1000 patients.
Event frequencies are calculated as the number of patients reporting an event divided by the total number of patients (N=1334) exposed to felbamate.
Body as a Whole :
Frequent: Weight increase, asthenia, malaise, influenza-like symptoms; Rare: anaphylactoid reaction, chest pain substernal.
Cardiovascular :
Frequent: Palpitation, tachycardia; Rare: supraventricular tachycardia.
Central Nervous System :
Frequent: Agitation, psychological disturbance, aggressive reaction: Infrequent: hallucination, euphoria, suicide attempt, migraine.
Digestive :
Frequent: SGOT increased; Infrequent: esophagitis, appetite increased; Rare: GGT elevated.
Hematologic :
Infrequent: Lymphadenopathy, leukopenia, leukocytosis, thrombocytopenia, granulocytopenia; Rare: antinuclear factor test positive, qualitative platelet disorder, agranulocytosis.
Metabolic/Nutritional :
Infrequent: Hypokalemia, hyponatremia, LDH increased, alkaline phosphatase increased, hypophosphatemia; Rare: creatinine phosphokinase increased.
Musculoskeletal :
Infrequent: Dystonia.
Dermatological :
Frequent: Pruritus; Infrequent: urticaria, bullous eruption; Rare: buccal mucous membrane swelling, Stevens-Johnson Syndrome.
Special Senses :
Rare: Photosensitivity allergic reaction. Postmarketing Adverse Event Reports Voluntary reports of adverse events in patients taking felbamate (usually in conjunction with other drugs) have been received since market introduction and may have no causal relationship with the drug(s).
E. syndrome, SIDS, sudden death, edema, hypothermia, rigors, hyperpyrexia. Cardiovascular : atrial fibrillation, atrial arrhythmia, cardiac arrest, torsade de pointes, cardiac failure, hypotension, hypertension, flushing, thrombophlebitis, ischemic necrosis, gangrene, peripheral ischemia, bradycardia, Henoch-Schönlein purpura (vasculitis).
Central & Peripheral Nervous System : delusion, paralysis, mononeuritis, cerebrovascular disorder, cerebral edema, coma, manic reaction, encephalopathy, paranoid reaction, nystagmus, choreoathetosis, extrapyramidal disorder, confusion, psychosis, status epilepticus, dyskinesia, dysarthria, respiratory depression, apathy, concentration impaired.
Dermatological : abnormal body odor, sweating, lichen planus, livedo reticularis, alopecia, toxic epidermal necrolysis. I. hemorrhage, hyperammonemia, pancreatitis, hematemesis, gastritis, rectal hemorrhage, flatulence, gingival bleeding, acquired megacolon, ileus, intestinal obstruction, enteritis, ulcerative stomatitis, glossitis, dysphagia, jaundice, gastric ulcer, gastric dilatation, gastroesophageal reflux.
Fetal Disorders : fetal death, microcephaly, genital malformation, anencephaly, encephalocele. Hematologic : (Refer to WARNINGS ) increased and decreased prothrombin time, anemia, hypochromic anemia, aplastic anemia, pancytopenia, hemolytic uremic syndrome, increased mean corpuscular volume (mcv) with and without anemia, coagulation disorder, embolism-limb, disseminated intravascular coagulation, eosinophilia, hemolytic anemia, leukemia, including myelogenous leukemia, and lymphoma, including T-cell and B-cell lymphoproliferative disorders.
Metabolic/Nutritional : hypernatremia, hypoglycemia, SIADH, hypomagnesemia, dehydration, hyperglycemia, hypocalcemia. Musculoskeletal : arthralgia, muscle weakness, involuntary muscle contraction, rhabdomyolysis. Respiratory : dyspnea, pneumonia, pneumonitis, hypoxia, epistaxis, pleural effusion, respiratory insufficiency, pulmonary hemorrhage, asthma.
Special Senses : hemianopsia, decreased hearing, conjunctivitis. Urogenital : menstrual disorder, acute renal failure, hepatorenal syndrome, hematuria, urinary retention, nephrosis, vaginal hemorrhage, abnormal renal function, dysuria, placental disorder.
Anyone considering prescribing felbamate or any other AED must balance the risk of suicidal thoughts or behavior with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior.
Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated. Patients, their caregivers, and families should be informed that AEDs increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts, behavior, or thoughts about self-harm.
Behaviors of concern should be reported immediately to healthcare providers.