Gabapentin

Gabapentin

[100mg tablet 10 cents]

ADMINISTRATION ROUTES:

• PO, NG

ALTERNATIVE NAMES:

• Neurotin, Nupentin

ICU INDICATIONS:

1. treatment of pain (particularly neuropathic pain)

Note: Gabapentin is an anticonvulsant but is not generally used for this indication in ICU

PRESENTATION AND ADMINISTRATION:

• PO:
  Capsules:
  Neurontin 100mg capsules (white), Neurontin 300mg capsules (yellow), Neurontin 400mg capsules (orange) Nupentin 100mg capsules (white), Nupentin 300mg capsules (yellow), Nupentin 400mg capsules (orange)
• Tablets:
  Neurontin 600mg tablets (white)

DOSAGE:

• PO / NG:
  Commence with 100mg three times a day and increase as tolerated to a usual maximum of 1800mg per day (in divided doses); doses of up to 3600mg per day (in divided doses) have occasionally been used.

  Note: Neurontin capsules can be opened and contents mixed with 10ml of water for administration via NG tube

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

• Dose in renal impairment [GFR (ml/min)]
  <15: usual dose 300mg on alternate days
  >15-30: usual dose 300mg once daily
  >30-60: usual dose 300mg twice daily
  60-90: usual dose 400mg three times daily
• Dose in renal replacement therapy
  CAPD: usual dose 300mg on alternate days
  HD: 200-300mg after each HD session
  CVVHDF: rarely indicated; increased doses may be required

DOSAGE IN PAEDIATRICS:

• PO:
  2mg/kg three times daily; increase to 15mg/kg or higher if tolerated

CLINICAL PHARMACOLOGY:

• Gabapentin is structurally related to the neurotransmitter GABA (gamma-aminobutyric acid). Its mechanism of action is unknown.

CONTRAINDICATIONS:

1. hypersensitivity to gabapentin

WARNINGS

• When gabapentin is used as an anticonvulsant, abrupt withdrawal may precipitate seizures

PRECAUTIONS

• General:
  See WARNINGS
• Laboratory Tests:
  No tests in addition to routine ICU tests are required.
• Drug/Laboratory Test Interactions:
  Because false positive readings were reported with the Ames N-Multistix SG dipstick test for urinary protein when gabapentin was added to other antiepileptic drugs, the more specific sulfosalicylic acid precipitation procedure is recommended to determine the presence of urine protein.

IMPORTANT DRUG INTERACTIONS FOR THE ICU

• None of note

ADVERSE REACTIONS

• Body as a Whole:
  Headache, abdominal pain
• Digestive System:
  Diarrhoea, dry mouth, constipation, nausea, vomiting, flatulence
• Metabolic and Nutritional Disorders:
  Weight gain, Hyperglycemia
• Nervous System:
  Dizziness, Somnolence, Ataxia, Abnormal gait, Incoordination, Amnesia, Hypesthesia
• Skin and Appendages:
  Rash