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. 

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

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

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

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.

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.

Not affected.

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.