Gabapentin: Mechanism of action not understood; antiepileptic activity may be related to its ability to inhibit polysynaptic responses and block post tetanic potentiation.
Apo-Gabapentin (CAN), Gen-Gabapentin (CAN), Neurontin
Pregnancy Category C
- Mechanism of action not understood; antiepileptic activity may be related to its ability to inhibit polysynaptic responses and block post tetanic potentiation.
- Adjunctive therapy in the treatment of partial seizures with and without secondary generalization in adults and children 3–12 yr with epilepsy
- Orphan drug use: Treatment of amyotrophic lateral sclerosis
- Management of postherpetic neuralgia or pain in the area affected by herpes zoster after the disease has been treated
- Unlabeled uses: Tremors of MS, neuropathic pain, bipolar disorder, migraine prophylaxis
Contraindications and cautions
- Contraindicated with hypersensitivity to gabapentin.
- Use cautiously with pregnancy, lactation.
Capsules—100, 300, 400 mg; tablets—100, 300, 400, 600, 800 mg; oral solution—250 mg/5 mL
- Epilepsy: Starting dose is 300 mg PO tid, then titrated up as needed. Maintenance: 900–1,800 mg/day PO in divided doses tid PO; maximum interval between doses should not exceed 12 hr. Up to 2,400–3,600 mg/day has been used.
- Postherpetic neuralgia: Initial dose of 300 mg/day PO; 300 mg bid PO on day 2; 300 mg tid PO on day 3.
PEDIATRIC PATIENTS 3–12 YR
Initially, 10–15 mg/kg/day PO in three divided doses; adjust upward over about 3 days to 25–35 mg/kg daily in three divided doses in children > 5 yr, and up to 40 mg/kg/day in three divided doses in children 3–4 yr.
GERIATRIC PATIENTS OR PATIENTS WITH RENAL IMPAIRMENT
|Cr/Cl (mL/min)||Dosage (mg/day)|
|> 60||900–3,600 in three divided doses|
|> 30–59||400–1,400 in two divided doses|
|> 15–29||200–700 in one dose|
|< 15||100–300 in one dose|
Postdialysis supplemental dosing, 125–350 mg PO following each 4 hr of dialysis.
Metabolism: Hepatic; T1/2: 5–7 hr
Distribution: Crosses placenta; enters breast milk
Excretion: Urine, unchanged
- CNS: Dizziness, insomnia, nervousness, fatigue, somnolence, ataxia, diplopia, tremor
- Dermatologic: Pruritus, abrasion
- GI: Dyspepsia, vomiting, nausea, constipation, dry mouth
- Respiratory: Rhinitis, pharyngitis
- Other: Weight gain, facial edema, cancer, impotence
- Decreased serum levels with antacids
- False positives may occur with Ames N-Multistix SG dipstick test for protein in the urine
- History: Hypersensitivity to gabapentin; lactation, pregnancy
- Physical: Weight; T; skin color, lesions; orientation, affect, reflexes; P; R, adventitious sounds; bowel sounds, normal output
- Give drug with food to prevent GI upset.
- Arrange for consultation with support groups for people with epilepsy.
- WARNING: If overdose occurs, hemodialysis may be an option.
- Take this drug exactly as prescribed; do not discontinue abruptly or change dosage, except on the advice of your health care provider.
- Wear a medical alert ID at all times so that any emergency medical personnel will know that you have epilepsy and are taking antiepileptic medication.
- You may experience these side effects: Dizziness, blurred vision (avoid driving or performing other tasks requiring alertness or visual acuity); GI upset (take drug with food or milk, eat frequent small meals); headache, nervousness, insomnia; fatigue (periodic rest periods may help).
- Report severe headache, sleepwalking, rash, severe vomiting, chills, fever, difficulty breathing.