What is the classification of Gabapentin (Anticonvulsant) medication?

From the Guidelines

Gabapentin is a recommended medication for the treatment of neuropathic pain, particularly for painful diabetic peripheral neuropathy, with a typical starting dose of 100-300 mg at bedtime or 100-300 mg three times daily, and titration up to a maximum dose of 3600 mg daily divided into three doses, as supported by recent guidelines and studies 1.

Key Points to Consider

• Gabapentin works by modulating calcium channels in the nervous system, reducing the release of excitatory neurotransmitters, and is FDA-approved for treating partial seizures and postherpetic neuralgia, with off-label use for neuropathic pain, fibromyalgia, anxiety disorders, and restless leg syndrome.
• The medication should be tapered gradually when discontinuing to avoid withdrawal symptoms, and requires dose adjustment in patients with kidney impairment as it's eliminated primarily through renal excretion.
• Common side effects include dizziness, drowsiness, peripheral edema, and fatigue, and the medication has a relatively favorable safety profile with minimal drug interactions since it's not metabolized by the liver, though it may enhance the effects of other central nervous system depressants.

Dosage and Administration

• Typical dosing starts low at 100-300 mg at bedtime or 100-300 mg three times daily, and gradually increases to an effective dose, often 300-600 mg three times daily, with maximum doses reaching 3600 mg daily divided into three doses.
• An adequate trial of treatment with gabapentin can require 2 months or more, and increases until pain relief, dose-limiting adverse effects, or 3600 mg/d in 3 divided doses is reached.

Comparison with Other Medications

• Pregabalin, another calcium channel alpha-2-delta ligand, has similar efficacy and tolerability to gabapentin, but with more straightforward dosing and linear pharmacokinetics, and may provide analgesia more quickly than gabapentin 1.
• Other medications, such as topical lidocaine, may also be effective for neuropathic pain, particularly for patients with allodynia or complex neuropathic pain, and have a favorable safety profile with minimal systemic absorption and drug interactions 1.

From the Research

Gabapentin Classification and Medication

• Gabapentin is classified as an antiepileptic drug 2, 3.
• It is used as adjunctive therapy in adults with epilepsy with partial and secondarily generalized tonic-clonic seizures 2.
• Gabapentin is also effective in the treatment of neuropathic pain, including postherpetic neuralgia and painful diabetic neuropathy 4, 5.

Mechanism of Action and Pharmacokinetics

• The mechanism of action of gabapentin remains to be defined, but it is effective in several seizure models 2.
• Gabapentin has a favorable pharmacokinetic profile and is generally well tolerated 2, 3.
• The drug can be rapidly titrated and is well tolerated in the treatment of neuropathic pain 4.

Clinical Efficacy and Safety

• Clinical studies support the clinical efficacy of gabapentin as adjunctive therapy in adults with epilepsy 2, 6.
• Gabapentin has been shown to be effective in reducing seizure frequency and improving quality of life in patients with epilepsy 6.
• The most common adverse effects of gabapentin include drowsiness, dizziness, and asthenia 6, 5.
• Gabapentin is considered a safe and well-tolerated antiepileptic drug with a wide therapeutic index 3.