Gabapentin
Anti-epileptic · GABA analogue
Indications
Adjunctive treatment of partial seizures with or without secondary generalization in patients not satisfactorily controlled by or intolerant to other anticonvulsants. Neuropathic pain.
Dosage
Adults: Seizures: Initially 300 mg once daily on day 1, then 300 mg twice daily on day 2, 300 mg three times daily on day 3. Then increase in 300 mg increments daily in three equally divided doses; max 800 mg three times daily. Neuropathic pain: Initially 300 mg once daily on day 1, then 300 mg twice daily on day 2, then 300 mg three times daily on day 3. Then increase in 300 mg increments daily; max 600 mg three times daily. Children: Not recommended for children under 6 yr; not recommended at doses over 50 mg/kg daily in children under 12 yr. Adjunctive treatment of focal seizures with or without secondary generalization: 2-6 yr, 10 mg/kg once daily on day 1, then 10 mg/kg twice daily on day 2, then 10 mg/kg 3 times daily on day 3, increased according to response to usual dose of 30-70 mg/kg daily in 3 divided doses; 6-12 yr, 10 mg/kg (max 300 mg) once daily on day 1, then 10 mg/kg…
Adverse Effects
Somnolence, dizziness, ataxia, fatigue, tremor, nystagmus, diplopia, rash, amblyopia, dysarthria, amnesia, asthenia, paraesthesia, arthralgia, purpura, leucopenia, anxiety, weight increase, UTI, pharyngitis. Diarrhoea, dry mouth, peripheral oedema, abnormal gait, abnormal thoughts, accidental injury, back pain, constipation, flatulence, nausea, confusion, hypoesthesia, vertigo, dyspnoea, fever, RTI, otitis media, pneumonia, appetite changes, hostility, emotional lability, depression, convulsions, increase in seizure frequency, onset of new seizure type, hyperkinesia, abnormal coordination, visual disturbances, hypertension, vasodilation, dental abnormalities, cough, rhinitis, skin disorders, impotence, flu-like symptoms, raised LFTs, fracture, abrasion.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Risk cannot be ruled out. Lactation: Caution advised or effect undetermined. Precautions: Renal impairment, haemodialysis, acute pancreatitis, history of psychotic illness. History of substance abuse. Absence seizures. Elderly. Monitor patients for suicidal thoughts. Risk of severe hypersensitivity reactions incl DRESS; investigate symptoms (e.g., fever, lymphadenopathy, rash) promptly. Risk of severe respiratory depression. Discontinuation of gabapentin and/or addition or substitution of alternative therapy should be gradual, over a minimum of 1 week.
Interactions
Antacids, opioids, St John's wort.
Advice to Patient
Take with or without meals. If you miss a dose take it as soon as you remember. If only 2 hours are left for taking next dose, skip the missed dose and return to normal schedule. Do not take double dose. If you are prescribed once daily dose, take dose at bedtime. Do not take medication within 2 hours of taking an antacid. Do not stop taking medication abruptly, gradually lower the dose and then stop. Contact prescriber if there are changes in mental status, headache, lack of sleep, nervousness, restlessness, anxiety, sleepiness, seizures, excitation, mania, abnormal thinking, suicidal thoughts, skin rash, skin irritation, change in gait, muscle cramps, tremors, change in urinary pattern, chest pain, palpitations or if there is worsening of condition. Avoid alcohol and caffeine during therapy. Take sufficient amount of fluids (2-3 litres per day) to maintain hydration, unless restricted…
Pharmacokinetics
Absorption: Variable, from proximal small bowel by L-amino transport system; saturable process; dose-dependent. Bioavailability: Inversely proportional to dose due to saturable absorption: Immediate release: 900 mg/day: 60%. 1200 mg/day: 47%. 2400 mg/day: 34%. 3600 mg/day: 33%. 4800 mg/day: 27%. Extended release: Variable; increased with higher fat content meal. Half-life elimination: Infants 1 mth-Children 12 yrs: 4.7 hrs. Adults, normal: 5-7 hrs; increased half-life with decreased renal function; Anuric adult patients: 132 hrs; Adults during haemodialysis: 3.8 hrs. Time to peak: Immediate release: Infants 1 mth-Children 12 yrs: 2-3 hrs; Adults: 2-4 hrs; Extended release: 8 hrs. Excretion: Proportional to renal function; urine (as unchanged drug).
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
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