What is the recommended dosage of gabapentin (Neurontin) for an adult patient with burning mouth symptoms, potentially related to neuropathic pain or laryngeal hypersensitivity in the context of Laryngopharyngeal Reflux (LPR) and Gastroesophageal Reflux Disease (GERD)?

Gabapentin Dosing for Burning Mouth Symptoms in LPR/GERD Context

For burning mouth symptoms potentially related to laryngeal hypersensitivity in the context of LPR/GERD, start gabapentin at 300 mg once daily at bedtime on day 1, increase to 300 mg three times daily (900 mg/day) by day 3, then titrate upward by 300 mg every 3-7 days until reaching a target therapeutic dose of 1800-3600 mg/day in three divided doses. 1, 2, 3

Initial Dosing Strategy

• Begin with 300 mg at bedtime on day 1, then 300 mg twice daily on day 2, then 300 mg three times daily (900 mg/day) by day 3. 2, 3
• This rapid initial titration to 900 mg/day is supported by randomized controlled trial data showing this approach balances efficacy with tolerability. 3
• Three-times-daily dosing is mandatory due to gabapentin's nonlinear, saturable absorption pharmacokinetics—once or twice daily dosing will not achieve therapeutic effect. 2

Target Therapeutic Dose

• The minimum effective dose for neuropathic pain conditions is 1800 mg/day (600 mg three times daily), with many patients requiring 2400-3600 mg/day for optimal symptom control. 2, 3
• Continue titrating by 300 mg increments every 3-7 days as tolerated until reaching 1800 mg/day, then assess response. 2, 3
• If inadequate response at 1800 mg/day after 2-4 weeks, continue titrating up to a maximum of 3600 mg/day (1200 mg three times daily). 2, 3

Evidence for Burning Mouth Syndrome

• Gabapentin has demonstrated effectiveness specifically for burning mouth syndrome, with case reports showing significant reduction in oral burning symptoms at doses ranging from 800-3600 mg/day. 4, 5
• The mechanism likely involves modulation of laryngeal hypersensitivity, as gabapentin and baclofen both reduced cough sensitivity and reflux symptoms in patients with suspected GER-related chronic cough. 1
• One case report documented complete symptom control of burning mouth syndrome with gabapentin after other treatments failed, though the specific dose was not detailed. 4

Duration of Adequate Trial

• Allow a minimum of 3-8 weeks for titration plus 2 weeks at maximum tolerated dose before declaring treatment failure—an adequate therapeutic trial may require 2 months or more. 2
• Pain relief with gabapentin develops gradually over several weeks, not immediately. 2
• Approximately 32-38% of patients achieve at least 50% pain reduction at therapeutic doses (1800-3600 mg/day) compared to 17-21% with placebo. 2

Special Population Considerations

• For elderly or medically frail patients, start at 100 mg at bedtime and use slower titration with increases every 3-7 days to reduce fall risk from dizziness. 2
• Mandatory dose reduction is required for renal impairment based on creatinine clearance, as gabapentin is eliminated primarily by renal excretion. 2

Critical Pitfalls to Avoid

• Do not use once-daily or twice-daily dosing—gabapentin's saturable absorption requires three-times-daily administration for efficacy. 2
• Do not rush titration in elderly patients, as this increases fall risk from dizziness and somnolence. 2
• Do not discontinue abruptly—taper gradually over at least 1 week to avoid withdrawal symptoms. 2
• Do not declare treatment failure before completing the full 2-month trial period, as efficacy develops gradually. 2

Common Side Effects

• Dizziness and somnolence are the most common dose-dependent side effects, typically mild to moderate and often transient, subsiding within approximately 10 days from initiation. 3
• In one trial of HIV-associated neuropathy, somnolence was reported by 80% of patients at 2400 mg/day, though this was in a specific population. 2
• Side effects can be minimized through gradual titration and may not require discontinuation—dose reduction often suffices. 3

Context-Specific Considerations for LPR/GERD

• Gabapentin addresses laryngeal hypersensitivity and hypervigilance, which may contribute to burning mouth symptoms in LPR/GERD patients beyond acid-mediated injury alone. 1
• This approach is supported by evidence showing gabapentin reduced cough sensitivity in patients with suspected GER-related chronic cough, suggesting benefit for laryngeal hypersensitivity syndromes. 1
• Gabapentin should be considered as adjunctive therapy to acid suppression, not as replacement for PPI therapy in confirmed LPR/GERD. 1, 6