Drug Interaction:
Interacting drugs- summary
Felbamate +Phenytoin or Phenytoin+ Felbamate- felbamate causes an increase in steady state phenytoin levels. To maintain phenytoin levels and acheive felbamate dosages of 3600mg/day, a 40% dose reduction of phenytoin was necessary.
Felbamate +Carbamzepine or Carbamzepine + Felbamate- Felbamate causes a decrease in steady-state carbamazepine epoxide ( metabolite ) levels. in addition, carbamazepine causes Carbamzepene an about 50% increase in felbamate clearance, resulting in 40% decrease in steady state tough levels
Valproic acid- Felbamate causes an increase in steady-state valproic acid levels.
Indication:
Partial seizures
ANTICONVULSANTS INCLUDES - BARBITURATES - OXAZOLIDINEDIONES- MISCELLANEOUS- Phenobarbitone Paramethadione Lamotrigine Trimethadione Primidone HYDANTOINS- Valproic acid Phenytoin
BENZODIAPINES- Cabamazepine Mephenytoin Clonazepam Phenacemide Ethotoin Clorazepate Felbamate Diazepam Gabapentin
SUCCINIMIDES- Ethosuximide Methsuximide Phensuximide
REFER PHENYTOIN SODIUM
Adverse Reaction:
Body as awhole- Fatigue, weight decrease, Facial edema, Fever, Chest pain,Pain
CNS- Insimnia, Headache, Anxiety, Somnolence, Dizziness, Nervousness, Tremor, Abnormal gait, Depression, Paresthesia, Ataxia, Dry mouth, Stupor, Thinking abnormal, Emotional lability, Miosis Dermatologic- Acne, Rash
GI- Dyspepsia, Vomiting, Constipation, Diarrhea, ALT increased, Nasuea, Anorexia, abdominal pain, Hiccups
Respiratory- Upper resipratory tract infection, Rhinitis, Sinusitis, Pharyngitis, coughing
Special senses- Diplopia, Ottis media, Taste perversion.Vision abnormal GU- Urinary incontinence, Intramenstrula bleeding, UTI
Hematologic- Purpura, Leukopenia, Lymphadenopathy, lekocytosis, thrombocytopenia, granulocytopenia
Miscelaaneous- Hypophosphatemia, Myalgia
Metabolic/ Nutrional- Hypokalemia, hyponatremia, LDH increased, alkaline phosphatas increased, hypophosphatemia, creatinine phosphokinase increased
Contra-Indications:
Hypersensitivity to felbamate.
Special precautions:
Apllastic anemia, hepatic failure. Withdrawal abruptly. Monitoring- clinical trials indicate that routine monitoring of clinical laboratory parameters is not necessary fo safe use of felbamate.The value of monitoring blood levels has not been established.
Photosensitivity-
photosewnsitization (photoallergy and phototoxicity ) may occur, therefore caution patients to take protective measures against exposure to ultraviolet light or sunlight.
Warnings-
Aplastic anemia- there have been reports of 21 cases aplastic anemia (including 3 deaths) in association with the use of felbamate.
Hepatic failure-
therechave been eight cases of caute liver failure ( including four deaths) in association with the use of felbamate.
Discontinuation-
antiepileptic drugs should not be suddenly dsicontinued because of possibility of increasing seizure frequency Elderly- clinical experience has not identified differences in responses between the elderly and younger patients.In general dosage selection for an elderly patient should be cautious usually starting at a low end of the dosing range,reflecting the greater frequency of decreased hepatic renal and cardiac function and of concomittant disease or other therapy.
Pregnancy-
use during pregnancy only if clearly needed.
Lactation-
Felbamate may be excreted in breast milk. The effect on the nursing infant is unknown
Children-
safety and efficacy in children , other than with Lennnox-Gastaut syndrome have not been established
Dosages/ Overdosage Etc:
Approved by FDA on July 29,1993
Indications:
Partial seizures
Dosage:
Monotherapy- adults more than 14 years of age- initiate at 1200mg/day in divided doses 3 or 4 times daily. Titrate previously untreated patients under close clinical supervision, increasing the dosage in 600mg increments every 2 weeks to 2400mg/day, based on clinical response and thereafter to 3600mg/day if clinically indicated.
Adjunctive therapy-
add felbanate at 1200mg/day in divided doses 3 or 4 times daily Ovedosage- Symptoms Only adverse experiences reported were mild gastric distress and a resting heart rate of 100 bpm. No serious adverse reactions have been reported
Treatment
1. Employ general supportive measures if overdosage occurs.
2. It is not known, if felbamate if dialyzable
Missed dose-
1. If you miss a dose of this medicine, take it as soon as possible.
2. However, if it is almost time for next dose, skip the missed dose and go back to your regular dosing schedule.
3. Do not double doses.
Patient Information:
Ref - USP PDI Vol II 17th Edition (1997)
1.Allergies-
Tell your doctor if you have ever had any unusual or allergic reaction to
felbamate. Also tell your healthcare care professional if you are allergic to any other
substances such as foods. preservatives or dyes.
2.Pregnancy-
Felbamate has not been studied in pregnant women. However, studies in pregnant
animals have shown felbamate may cause lowered birth rate and lowered survival
of offspings. Before taking this medicine make sure your doctor knows if you are
pregnant or if you become pregnant.
3. Breast-feeding-
Felbamate passes into breast milk. It is not known whether this medicine causes
problems in nursing babies.
4.Children-
This medicine has some very serious causes unwanted effects. Felbamate should
be used in children only if other medicines have not controlled their seizures.
5.Older adults-
Many medicines have not been studied specifically in older people. Therefore,
it may not be known whether they work exactly the same way they do in
younger adults, or if they cause different side effects or problems in older people.
There is no specific information comparing use of felbamate in the elderly with use
in other age groups
6. Other medicines-
Although certain medicines should not be used together at all, in other cases two
different medicines may be used together even if an interaction might occur.
In such cases your doctor may want to change the dose, or other precautions
may be necessary.
Tell your doctor if you are using any of the following medicines.
Carbamazepine
Phenytoin
Valproic acid - higher or lower blood levels of these medicines or felbamate may
occur
7. Other medical problems-
The presence of other medical problems may affect the use of felbamate.
Make sure you tell your doctor if you have any other medical problems
especially-
Asthma or blood problems or
Liver problems or history of- felbamate may make the condition worse.
Pharmacology/ Pharmacokinetics:
ANTICONVULSANTS INCLUDES
- BARBITURATES - OXAZOLIDINEDIONES- MISCELLANEOUS-
Phenobarbitone Paramethadione Lamotrigine Trimethadione Primidone HYDANTOINS- Valproic acid Phenytoin BENZODIAPINES- Cabamazepine Mephenytoin Clonazepam Phenacemide Ethotoin Clorazepate Felbamate Diazepam Gabapentin SUCCINIMIDES- Ethosuximide Methsuximide Phensuximide
REFER- PHENYTOIN SODIUM
Pharmacology:
Felbamate is oral antiepileptic agent. The mechanism of action is unknown.
Pharmacokinetics:
Flbamate is well absorbed after oral administration. Over 90% of a 1000mg dose was found in the urine. No effect of food on tablet absorption. Falbamate is excreted with a terminal half-life of 2 to 23 hours, which is altered after multiple doses.
Interaction with Food:
Not affected.
Pregnancy and lactation:
Pregnancy:
Use during pregnancy only if needed.
Lactation:
The effect on the nursing infant is unknown. Use only if required.
Children:
Safety and efficacy on children have not been established.
Manufacturer Details