Indications:

Adjunctive Treatment of Focal Seizures

• By Mouth:

• • Children 6–11 years:

• • • Day 1: 10 mg/kg once daily (max. 300 mg).
    • Day 2: 10 mg/kg twice daily (max. 300 mg per dose).
    • Day 3: 10 mg/kg three times a day (max. 300 mg per dose).
    • Usual dose: 25–35 mg/kg daily in 3 divided doses; max. 70 mg/kg per day.
    • Note: Daily increments may not be tolerated; consider longer intervals (up to weekly).

• • Children 12–17 years and Adults:

• • • Day 1: Initially 300 mg once daily.
    • Day 2: 300 mg twice daily.
    • Day 3: 300 mg three times a day.
    • Alternatively, start with 300 mg three times a day and increase by 300 mg every 2–3 days in 3 divided doses.
    • Usual dose: 0.9–3.6 g daily in 3 divided doses (max. per dose 1.6 g).

Monotherapy for Focal Seizures

• By Mouth:

• • Children 12–17 years and Adults:

• • • Same dosing schedule as adjunctive treatment for focal seizures.

Peripheral Neuropathic Pain

• By Mouth (Adults):

• • Day 1: Initially 300 mg once daily.
  • Day 2: 300 mg twice daily.
  • Day 3: 300 mg three times a day.
  • Alternatively, start with 300 mg three times a day and increase in steps of 300 mg every 2–3 days in 3 divided doses.
  • Maximum: 3.6 g per day.

Menopausal Symptoms in Women with Breast Cancer

• By Mouth (Adults):

• • 300 mg three times a day, with initial dose titrated up over three days.

Oscillopsia in Multiple Sclerosis

• By Mouth (Adults):

• • Initially 300 mg once daily, then increased in steps of 300 mg every 4–7 days.
  • Usual maximum: 900 mg three times a day.

Spasticity in Multiple Sclerosis

• By Mouth (Adults):

• • Initially 300 mg once daily for 1–2 weeks, then 300 mg twice daily for 1–2 weeks, then 300 mg three times a day for 1–2 weeks.
  • Alternatively, start with 100 mg three times a day, increasing in steps of 100 mg every 1–2 weeks.
  • Usual maximum: 900 mg three times a day.

Muscular Symptoms in Motor Neuron Disease

• By Mouth (Adults):

• • Initially 300 mg once daily for 1–2 weeks, then 300 mg twice daily for 1–2 weeks, then 300 mg three times a day for 1–2 weeks.
  • Usual maximum: 900 mg three times a day.

Cautions

• Diabetes Mellitus: Monitor blood sugar levels as Gabapentin may affect glycemic control.
• Elderly: Lower doses may be necessary due to increased sensitivity to side effects.
• Adolescents and Adults with Low Body Weight: High doses of oral solution may increase the risk of adverse effects.
• History of Substance Abuse: Monitor for signs of misuse or dependence.
• Respiratory Depression: Be cautious in patients with underlying respiratory disorders.
• Seizures: Gabapentin may exacerbate seizures in some types of epilepsy such as absence or myoclonic seizures, Dravet syndrome, Lennox-Gastaut syndrome, and myoclonic-atonic seizures.

Side Effects

• Common or Very Common: Anxiety, abnormal appetite, arthralgia, asthenia, abnormal behavior, confusion, constipation, cough, depression, diarrhea, dizziness, drowsiness, dry mouth, dysarthria, dyspnea, emotional lability, fever, flatulence, abnormal gait, gastrointestinal discomfort, headache, hypertension, increased risk of infection, insomnia, leucopenia, malaise, memory loss, movement disorders, muscle complaints, nausea, nystagmus, oedema, pain, abnormal reflexes, abnormal sensation, sexual dysfunction, skin reactions, abnormal thinking, tooth disorders, tremor, vasodilation, vertigo, visual impairment, vomiting.
• Uncommon: Cognitive impairment, dysphagia, palpitations.
• Rare or Very Rare: Respiratory depression.
• Frequency Not Known: Acute kidney injury, alopecia, angioedema, breast enlargement, drug use disorders, gynecomastia, hallucinations, hepatic disorders, hyponatremia, pancreatitis, rhabdomyolysis, severe cutaneous adverse reactions (SCARs), suicidal behaviors, thrombocytopenia, tinnitus, urinary incontinence, withdrawal syndrome.

Special Considerations

• Pregnancy: Use only if the benefit outweighs the risk due to reported toxicity.
• Breastfeeding: Present in milk; weigh the potential benefits against risks.
• Renal Impairment: Dose adjustments are necessary based on creatinine clearance levels.

Dosing Adjustments in Renal Impairment

• Adults:

• • Creatinine clearance 50–79 mL/minute: Reduce dose to 600-1800 mg daily in 3 divided doses.
  • Creatinine clearance 30–49 mL/minute: Reduce dose to 300–900 mg daily in 3 divided doses.
  • Creatinine clearance 15–29 mL/minute: Reduce dose to 150–600 mg daily in 3 divided doses, given on alternate days.
  • Creatinine clearance <15 mL/minute: Reduce dose to 150–300 mg daily in 3 divided doses, given on alternate days.

Monitoring Requirements

• Gabapentin Abuse: Monitor for signs of abuse, especially in patients with a history of substance abuse.

Effect on Laboratory Tests

• False positive readings may occur with some urinary protein tests.

Directions for Administration

• Capsules can be opened but have a bitter taste that is difficult to mask.

Patient and Carer Advice

• Inform patients and carers about the availability of specific educational resources and patient leaflets detailing the use of Gabapentin for neuropathic pain and seizure prevention.

Medicinal Forms and Availability

Oral Suspension & Oral Solution

• • Available from special-order manufacturers.
  • Excipients may include propylene glycol.
  • Electrolytes in the formulation may contain potassium and sodium.

Tablet

• • Gabapentin 600 mg Tablets (Non-proprietary)
  • Gabapentin 800 mg Tablets (Non-proprietary)
  • Neurontin 600 mg Tablets (Viatris UK Healthcare Ltd)
  • Neurontin 800 mg Tablets (Viatris UK Healthcare Ltd)

Oral Solution

• • Gabapentin 50 mg per 1 ml Oral Solution (Non-proprietary)
  • Neurontin 250 mg/5ml Oral Solution
  • Gabapentin 50 mg/ml Sugar-Free Oral Solution (Non-proprietary)

Capsule

• • Gabapentin 100 mg, 300 mg, 400 mg Capsules (Non-proprietary)
  • Neurontin 100 mg, 300 mg, 400 mg Capsules (Viatris UK Healthcare Ltd)