What is the use of Gabapentin (Neurontin)?

From the Guidelines

Gabapentin is recommended as a first-line treatment for neuropathic pain, with a typical starting dose of 300mg once daily, gradually increasing to 300-600mg three times daily as needed, with a maximum daily dose of 3600mg, as supported by the most recent and highest quality study 1.

Key Points to Consider

• The medication works by binding to calcium channels in the nervous system, reducing the release of excitatory neurotransmitters that cause pain and seizure activity.
• Patients should take gabapentin with food to improve absorption and reduce stomach upset.
• When starting gabapentin, it's essential to begin with a low dose and gradually increase to minimize side effects like dizziness, drowsiness, and fatigue.
• Effective doses for nerve pain usually range from 1200-3600mg daily divided into three doses.
• Common side effects include drowsiness, dizziness, peripheral edema, and in some cases, mood changes or suicidal thoughts, which should be reported to a healthcare provider immediately.
• Gabapentin may interact with opioids and other central nervous system depressants, potentially causing dangerous respiratory depression, as noted in 1 and 1.

Important Considerations for Treatment

• Dose titration: Gradually increase the dose to minimize side effects, with dose increments of 50%-100% every few days, as recommended in 1.
• Renal insufficiency: Dose adjustment is required for patients with renal insufficiency, as noted in 1 and 1.
• Elderly or medically frail patients: Slower titration is recommended for these patients, as mentioned in 1.
• Monitoring: Regular monitoring of patients is crucial to assess the efficacy and tolerability of gabapentin, as emphasized in 1 and 1.

From the FDA Drug Label

Gabapentin Tablets, USP 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 tablets are a prescription medicine used to treat: Pain from damaged nerves (postherpetic pain) that follows healing of shingles (a painful rash that comes after a herpes zoster infection) in adults Partial seizures when taken together with other medicines in adults and children 3 years of age and older with seizures.

The main uses of Gabapentin are:

• Management of postherpetic neuralgia in adults
• Adjunctive therapy in the treatment of partial onset seizures in adults and pediatric patients 3 years and older with epilepsy
• Treatment of pain from damaged nerves (postherpetic pain) that follows healing of shingles in adults
• Treatment of partial seizures when taken together with other medicines in adults and children 3 years of age and older with seizures 2 2.

From the Research

Gabapentin Overview

• Gabapentin is commonly used to treat neuropathic pain (pain due to nerve damage) 3.
• It is effective in providing good levels of pain relief to some people with postherpetic neuralgia and peripheral diabetic neuropathy 3.
• Around 3 or 4 out of 10 participants achieved at least 50% pain relief with gabapentin, compared with 1 or 2 out of 10 for placebo 3.

Comparison with Pregabalin

• There is no significant difference in meaningful pain reduction with gabapentin versus pregabalin 4.
• Pregabalin may afford better tolerability and lower pill burden compared to gabapentin 4.
• Pregabalin showed superior results compared to gabapentin in the Visual Analog Scale (VAS) at various time intervals up to 12-14 weeks 5.
• Pregabalin resulted in lower opioid consumption and led to fewer adverse events compared to gabapentin 5.

Mechanism of Action

• Gabapentin may have a unique effect on voltage-dependent Ca2+ channel currents at postsynaptic dorsal horn neurons, interrupting the development of neuropathic pain 6.
• Gabapentin effectively antagonizes the maintenance of neuropathic pain in preclinical models 6.

Combination Therapy

• Gabapentin and pregabalin can be used in combination to reduce the dose of an individual agent, its side effects, and to enhance therapeutic response compared to a single agent 7.
• This combined approach can be used to treat refractory pain situations and in patients with low levels of tolerance for an individual agent 7.