What's the next step for a patient with a history of surgeries and staples in the affected area, who has been taking gabapentin (Neurontin) 100 mg three times a day (TID) for 30 days, but reports no relief from neuralgia?

Management of Inadequate Neuralgia Response to Gabapentin 100 mg TID

Your patient is on a subtherapeutic dose of gabapentin—you need to titrate upward to at least 1800 mg/day (600 mg three times daily), which is the minimum effective dose for neuropathic pain conditions. 1

Why the Current Dose is Inadequate

• Gabapentin 100 mg TID (300 mg/day total) is far below the therapeutic range for neuropathic pain, which requires 1800-3600 mg/day in divided doses 1, 2, 3
• The current dose represents only 17% of the minimum effective dose, explaining the lack of pain relief 1
• Gabapentin has nonlinear, saturable absorption pharmacokinetics, making proper dose titration essential for efficacy 1

Recommended Titration Protocol

Follow this specific escalation schedule:

• Week 1-2: Increase to 300 mg three times daily (900 mg/day total) 1, 2
• Week 2-3: Increase to 600 mg three times daily (1800 mg/day total)—this is the minimum effective dose 1
• Week 4-6: If inadequate response at 1800 mg/day, continue titrating by 300 mg increments every 3-7 days up to 3600 mg/day (1200 mg three times daily) as tolerated 1, 2
• Allow 3-8 weeks for titration plus 2 weeks at maximum tolerated dose before declaring treatment failure—an adequate trial can require 2 months or more 1

Expected Outcomes at Therapeutic Doses

• Approximately 35-38% of patients achieve at least 50% pain reduction with gabapentin at therapeutic doses (1800-3600 mg/day), compared to 21% with placebo 1, 4
• Pain relief develops gradually over several weeks, not immediately 1
• Common side effects include dizziness (19%), somnolence (14%), and peripheral edema (7%), which are typically mild to moderate and often transient 1, 3

Critical Considerations for Post-Surgical Neuralgia

• For post-surgical/post-traumatic neuropathic pain (which your patient has from staples and surgery), gabapentin is a reasonable first-line agent 1, 5
• Three-times-daily dosing is mandatory due to gabapentin's saturable absorption—once or twice daily dosing will not work 1
• The maximum time between doses should not exceed 12 hours 2

Important Pitfalls to Avoid

• Do not declare treatment failure at 300 mg/day—this dose is pharmacologically insufficient 1
• Do not rush titration, especially if the patient is elderly or has renal impairment, as this increases fall risk from dizziness 1, 6
• Check renal function—gabapentin requires dose adjustment based on creatinine clearance 1, 2
• Do not discontinue abruptly if switching medications—taper gradually over at least 1 week to avoid withdrawal symptoms 2

Alternative Considerations if Gabapentin Fails at Therapeutic Doses

If the patient fails to respond after reaching 1800-3600 mg/day for at least 2 weeks at maximum tolerated dose:

• Consider switching to pregabalin (more predictable pharmacokinetics) or amitriptyline 75 mg at bedtime (shown to lower daily pain ratings in neuropathic pain) 7
• Lamotrigine is another option, though only 44% of patients have a good clinical response 7
• Combination therapy with gabapentin plus topical agents, antidepressants, or opioids may be needed for optimal pain management 1

Monitoring Strategy

• Reassess pain levels using standardized measures (visual analog scale or pain diary) every 1-2 weeks during titration 7
• Monitor for side effects, particularly dizziness and sedation, which may require slower titration 1
• Educate the patient that efficacy develops gradually and requires patience with dose escalation 1