OBJECTIVES: Real-world data comparing gastroretentive gabapentin (G-GR) and pregabalin for post-herpetic neuralgia treatment is limited. The study had two objectives: compare adherence and treatment patterns, and compare all-cause and pain-related post-index healthcare costs in patients in patients newly initiating G-GR or pregabalin. METHODS: A retrospective cohort study was conducted of members enrolled under a Medicare Prescription Drug plan or a fully-insured commercial plan. Individuals with new prescription claims for G-GR or pregabalin between October 1, 2011, and March 31, 2013, were included. Six-month pre-index (prescription claim date) and post-index periods with continuous plan enrollment were required. Treatment groups were matched on pain-related diagnosis, baseline comorbidity status, age, and race. RESULTS: The median G-GR dose was 1800 mg (100% of recommended therapeutic dose [TD]); the pregabalin median dose was 150 mg (50% of TD) (p<0.0001). Full TD was achieved in 30% of pregabalin and 66% of G-GR patients. The average time to achieve TD was 29.7 days for pregabalin and 5.4 days for G-GR (p<0.0001). Before and during the study, opioid use was more prevalent among the G-GR cohort. Pre-index, 86% of the G-GR cohort and 79% of the pregabalin cohort, had an opioid prescription (p=0.013). Post-index, opioid use dropped minimally for both cohorts to 84% and 77%, respectively (p=0.006). In patients receiving opioids both before and after index, the median post-index dose increase was 300mg morphine equivalent dose (MED) for pregabalin and 7.5 mg for G-GR (p=NS). Total healthcare costs were comparable between cohorts. CONCLUSIONS: Adherence was similar in patients treated with pregabalin and G-GR. A higher percentage of patients receiving G-GR achieved the recommended TD and did so more rapidly. Despite a potentially greater pre-index burden suggested by greater pre-index opioid use in the G-GR cohort, post-index dose increases were similar between cohorts.