Use of Gabapentin for Postherpetic Neuralgia: Results of Two Randomized, Placebo-Controlled Studies

Background: Postherpetic neuralgia (PHN), which affects up to 70% of elderly persons with herpes zoster, can have debilitating effects, including physical and social disability and significant psychological distress. A variety of agents have been used, either singly or in combination, to control PHN, including topical and oral analgesics, antidepressants, and antiepileptic drugs (AEDs). However, PHN often proves refractory to these therapies. Objective: This article reviews available data on the use of the newer AED gabapentin for the control of PHN. Methods: A MEDLINE search was undertaken to identify all randomized, placebo-controlled trials on the use of gabapentin in PHN. The search terms were gabapentin and postherpetic neuralgia. Results: The literature search identified 2 published studies of the efficacy of gabapentin in a total of 563 patients with PHN that had persisted for at least 3 months after the healing of herpes zoster rash. The studies employed multiple outcome measures, including visual analog and Likert scales for pain intensity, and quality-of-life and functional measures that included the Medical Outcomes Study 36-item Short Form Health Survey (SF-36) and the Profile of Mood States. At maximum target dosages of 1800 to 3600 mg/d, gabapentin produced significant reductions in mean daily pain scores compared with placebo on both visual analog (P < 0.001) and Likert scales (P < 0.01). Improvements were also seen on the SF-36 subscales for physical functioning, bodily pain, vitality, and mental health (P < 0.01). Conclusion: Gabapentin may provide benefits in terms of alleviation of pain and overall quality of life in patients with chronic PHN.