Real-World Treatment of Post-herpetic Neuralgia with Gabapentin or Pregabalin

BACKGROUND AND OBJECTIVES There are limited data examining the real-world use of gabapentin and pregabalin for the treatment of post-herpetic neuralgia (PHN). This study examines dosing patterns, therapy outcomes, healthcare utilization and costs of patients with PHN who initiate treatment with gabapentin or pregabalin. METHODS This was a retrospective administrative claims data analysis from July 2005 to February 2010. Patients with PHN initiating gabapentin or pregabalin (index therapy) from January 2006 to February 2009 were identified and were observed for 12 months after index therapy initiation. Outcomes were mean daily dosages of the index therapy, attainment of minimally effective dosages of gabapentin (≥ 1,800 mg/day) or pregabalin (≥ 150 and ≥ 300 mg/day) persistence, discontinuation, index therapy switching, addition of neuropathic pain medications to index therapy, and healthcare resource use and costs. RESULTS 1,645 patients were identified. The mean daily dosage was 826 mg for gabapentin and 187 mg for pregabalin. Only 52.6 % of patients initiating gabapentin and 56.9 % initiating pregabalin obtained a refill during the post-index period. Approximately 14 % of patients treated with gabapentin reached the target dosage (1,800 mg/day). For pregabalin, 87 % reached ≥ 150 mg/day and 27 % reached ≥ 300 mg/day. On average, patients took 10 weeks to reach 1,800 mg/day gabapentin, and 5.0 and 9.2 weeks to reach ≥ 150 mg/day and ≥ 300 mg/day pregabalin, respectively. Approximately one-third of patients in both index therapy cohorts added a pain medication; more than half added opioids. The percentage of patients switching from either drug (57 %) or adding a therapy (34 %) were similar between index therapy cohorts; opioids were the most common therapy patients switched to or added. CONCLUSION It appears that gabapentin and pregabalin are not used effectively to treat PHN. Suboptimal dosing and discontinuation may be associated with supplementary use of other analgesics, especially opioids.