GABAMAX

Pharmacokinetics

• Absorption : Absorbed from the gastrointestinal tract
• Peak Plasma Concentration : 2 to 3 hours
• Protein Binding : Minimal
• Distribution : Widely distributed throughout the body; into breast milk
• Metabolism : Not appreciably metabolized
• Elimination Half-life : 5 to 7 hours
• Excretion : Excreted through urine as unchanged drug

Indications and Dosage
Adult

• Postherpetic Neuralgia
  Initial : One capsule of GABAMAX 300 mg on day 1, then one capsule of GABAMAX 300 mg twice daily on Day 2, and one capsule of GABAMAX 300 mg three times a day on Day 3
  Titrate : May subsequently increase up to GABAMAX 600 mg three times a day (1800 mg per day) if necessary
• Adjuvant Therapy for Partial Onset Seizures with Epilepsy, with or without Secondary Generalization
  Initial : One capsule of GABAMAX 300 mg three times a day
  Maintenance : One to two capsules of GABAMAX 300 mg three times a day
  Doses up to GABAMAX 2400 mg per day (long-term) and GABAMAX 3600 mg per day (short-term) have been well tolerated.
  Dosing intervals should not exceed 12 hours.

Children

• Adjuvant Therapy for Partial Onset Seizures with Epilepsy, with and without Secondary Generalization :
• 3 to 11 years
  Initial : GABAMAX 10 to 15 mg per kg per day in 3 divided doses
  Titrate : Increase to recommended maintenance dose over a period of approximately 3 days
• 3 to 4 years
  Maintenance : GABAMAX 40 mg per kg per day in 3 divided doses
• 5 to 11 years
  Maintenance : GABAMAX 25 to 35 mg per kg per day in 3 divided doses
  Doses up to GABAMAX 50 mg per kg per day have been well tolerated. Dosing intervals should not exceed 12 hours.
• 12 years of age or above
  Initial : One capsule of GABAMAX 300 mg three times a day
  Maintenance : One to two capsules of GABAMAX 300 mg three times a day
  Doses up to GABAMAX 2400 mg per day (long-term) and GABAMAX 3600 mg per day (short-term) have been well tolerated. Dosing intervals should not exceed 12 hours.
• Renal Impairment
  12 years of age or above
  Creatinine Clearance (CrCl) more than or equal to 60 mL per min : GABAMAX 900 to 3600 mg in 3 divided doses
  CrCl 30 to 59 mL per min : GABAMAX 400 to 1400 mg per day in 2 divided doses
  CrCl 15 to 29 mL per min : GABAMAX 200 to 700 mg in single daily dose
  CrCl 15 mL per min : One capsule of GABAMAX 100 to 300 mg single daily dose
  CrCl less than 15 mL per min : Reduce daily dose in proportion to CrCl
  Hemodialysis : Dose adjustment is necessary
• Discontinuation
  Dose Reduction / Substitution / Discontinuation : Should be done gradually over a minimum of 1 week

ADMINISTRATION : Oral route. Take with or without food. Swallow capsule whole with water.

Side Effects
MOST COMMON : Somnolence, dizziness, ataxia, fatigue
COMMON : Confusion, depression, nervousness
LESS FREQUENT : Nystagmus, tremor, diplopia, amblyopia, pharyngitis, rhinitis, dysarthria, nausea and vomiting, weight gain, oedema, dyspepsia, amnesia, weakness, paraesthesia, arthralgia, purpura, leucopenia, anxiety, urinary-tract infection
RARE : Pancreatitis, altered liver function tests, erythema multiforme, Stevens-Johnson syndrome, myalgia, headache, blood glucose fluctuations in diabetic, hallucinations and psychoses
OTHER : Acute renal failure, allergic reactions, movement disorders such as choreoathetosis, dyskinesia and dystonia, palpitations, thrombocytopenia, and tinnitus

Contraindication
Hypersensitivity

Warnings / Precautions

• In renal impairment and those undergoing haemodialysis, false positive readings have been reported with some urinary protein tests in patients taking gabapentin.
• Do not discontinue abruptly (may increase seizure frequency); gradually taper over a minimum of 1 week

Drug Interactions

• Antacids containing aluminium hydroxide, aluminium with magnesium decreases absorption of gabapentin.
• Morphine reduces the clearance of gabapentin (patients receiving both drugs should be monitored for signs of CNS depression and doses should be reduced accordingly.
• Increased plasma concentrations with symptoms of toxicity of phenytoin, carbamazepine, and clobazam have been reported in a patient after gabapentin was added to the treatment.

Pregnancy Category : C

Presentations
GABAMAX 100 mg: A box of 10 blisters, each blister of 10 capsules
GABAMAX 300 mg: A box of 10 blisters, each blister of 10 capsules

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