Pregabalin and gabapentin in matched patients with peripheral neuropathic pain in routine medical practice in a primary care setting: Findings from a cost-consequences analysis in a nested case-control study

Abstract

Background: Pregabalin and gabapentin are marketed to treat peripheral neuropathic pain, but head-to-head comparison is lacking. Objectives: The aims of this work were to compare the effects of pregabalin and gabapentin on different patient-reported health outcomes and to analyze health care and nonhealth-care resource consumption and their related costs among patients treated for peripheral neuropathic pain in primary medical care. Methods: A cost-consequences comparison in subjects with refractory (suboptimal response to ≥1 previous analgesic treatment for >6 months) chronic peripheral neuropathic pain was carried out using data extracted from two 12-week, observational, prospective studies in primary medical care. Patients were eligible if they were aged ≥18 years, had a score of ≥4 on the Douleur Neuropathique 4 questionnaire, and were able to complete health questionnaires written in Spanish. A nested-paired case-control design was chosen to perform the comparison with 2 controls (pregabalin) per case (gabapentin) matched by age, sex, peripheral neuropathic pain condition, time since diagnosis, number of previous treatments, pain intensity, depressive and anxiety symptom scores, and health state. Adult subjects with refractory chronic pain because of diabetic neuropathy, postherpetic or trigeminal neuralgias, or cervical or lumbosacral radiculopathies were included. Epidemiologic statistical methods were applied for comparing health effects (pain intensity, sleep, anxiety and depressive symptoms, disability, and health state), resources utilization, and related cost variations after 12 weeks. Indirect costs were measured by means of lost-workday equivalent calculations multiplied by the mean national daily salary. Results: Analysis included 44 patients treated with gabapentin (cases) and 88 patients treated with pregabalin (controls) who were matched for age, sex, and other parameters. The mean (SD) gabapentin and pregabalin doses were 1263 (540) and 202 (119) mg/d, respectively. Although there was a greater reduction in last-week mean pain intensity with pregabalin (visual analog scale: 39.1 [22.5] vs 28.0 [22.2] mm; P = 0.008), as well as more patients with a ≥50% reduction in pain rate (60.9% vs 40.5%; P = 0.029), there were no significant differences between groups for sensory, affective, total, or present pain intensity. The significantly higher drug cost associated with pregabalin was offset by a greater reduction in productivity costs compared with gabapentin, yielding similar cost reduction (−€1254 [1479] vs −€1384 [2874], respectively; P = NS). Conclusion: Pregabalin appeared to be associated with greater reduction in mean weekly intensity of pain, but there were no significant differences in cost.