Gabapentin

What it is and how it works

Mechanism of Action The precise mechanism by which gabapentin produces its antiepileptic action is unknown. Gabapentin is structurally related to the neurotransmitter gamma-aminobutyric acid (GABA) but has no effect on GABA binding, uptake, or degradation. In vitro studies have shown that gabapentin binds with high-affinity to the α2δ subunit of voltage-activated calcium channels; however, the relationship of this binding to the therapeutic effects of gabapentin is unknown.

Indications

Gabapentin capsules are indicated for: • Management of postherpetic neuralgia in adults • Adjunctive therapy in the treatment of partial onset seizures, with and without secondary generalization, in adults and pediatric patients 3 years and older with epilepsy Gabapentin capsules are indicated for: • Postherpetic neuralgia in adults • Adjunctive therapy in the treatment of partial onset seizures, with and without secondary generalization, in adults and pediatric patients 3 years and older with epilepsy

Dosage and administration (summary)

• Postherpetic Neuralgia • Dose can be titrated up as needed to a dose of 1800 mg/day • Day 1: Single 300 mg dose • Day 2: 600 mg/day (i.e., 300 mg two times a day) • Day 3: 900 mg/day (i.e., 300 mg three times a day) • Epilepsy with Partial Onset Seizures • Patients 12 years of age and older: starting dose is 300 mg three times daily; may be titrated up to 600 mg three times daily. • Patients 3 to 11 years of age: starting dose range is 10 to 15 mg/kg/day, given in three divided doses; recommended dose in patients 3 to 4 years of age is 40 mg/kg/day, given in three divided doses; the recommended dose in patients 5 to 11 years of age is 25 to 35 mg/kg/day, given in three divided doses.

Contraindications

Gabapentin capsules are contraindicated in patients who have demonstrated hypersensitivity to the drug or its ingredients. • Known hypersensitivity to gabapentin or its ingredients

Warnings and precautions

• Drug Reaction with Eosinophilia and Systemic Symptoms (Multiorgan hypersensitivity): Discontinue if alternative etiology is not established • Anaphylaxis and Angioedema: discontinue and evaluate patient immediately • Driving Impairment; Somnolence/Sedation and Dizziness: warn patients not to drive until they have gained sufficient experience to assess whether their ability to drive or operate heavy machinery will be impaired ( 5.3 , 5.4 ) • Increased seizure frequency may occur in patients with seizure disorders if gabapentin is abruptly discontinued • Suicidal Behavior and Ideation: monitor…

Storage and supply

Gabapentin Capsules, USP are supplied as follows: 100 mg capsules: The 100 mg capsule is a #3 capsule with a white opaque cap, white opaque body, imprinted "Є509" in blue ink on cap and body, filled with white to off-white powder.

Source: Gabapentin (Gabapentin) — US FDA prescribing information, 2019-01-07, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.