Pain Alleviation and Patient-Reported Health Outcomes following Switching to Pregabalin in Individuals with Gabapentin-Refractory Neuropathic Pain in Routine Medical Practice

Background: It has been suggested that peripheral neuropathic pain (PNP) may affect up to 3% of the general population. PNP has a substantial negative impact on patient functioning and quality of life, including reduced productivity and increased consumption of healthcare resources. Objective: The objective of this study was to analyse changes in pain and patient-reported health outcomes following switching to pregabalin treatment in patients with gabapentin-refractory PNP as part of routine clinical practice in Spanish primary-care settings. Methods: This was an open-label, non-randomized, post hoc analysis of a 12-week, multicentre, non-interventional cost-of-illness study. The study involved primary-care physicians and was carried out between September 2005 and April 2006. Patients were aged at least 18 years and had chronic, treatment-refractory PNP. The analysis included all pregabalin-naive patient switches that had previously shown an inadequate response to gabapentin. The following variables were assessed before and after pregabalin therapy: pain (Short-Form McGill Pain Questionnaire [SF-MPQ]), disability level (Sheehan Disability Scale [SDS]), symptoms of anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), self-perceived sleep quality and quantity (Medical Outcomes Study [MOS] Sleep Scale), and health-related quality of life (EuroQol [EQ] five-dimension [5D] questionnaire). Results: A total of 174 patients with an inadequate response to gabapentin switched to pregabalin at the beginning of the study. After 12 weeks of pregabalin therapy, alone or in combination with other analgesic drugs, significant and clinically relevant improvements were observed in pain severity [mean (SD) SF-MPQ change: -31.9 (22.1) points; 42.5% being responders (pain reduction >= 50%)], disability [SDS score: -7.5 (6.2) vs baseline], affective symptoms [HADS depression: -4.5 (3.9); HADS anxiety: -4.1 (3.7)], sleep [MOS summary index: -17.2 (16.6)], and health status [EQ-5D visual analogue scale (VAS): 27.3 (18.2)], with an overall gain of 0.040 (0.031) quality-adjusted life-years. Conclusion: These findings suggest that pregabalin could be a valid treatment alternative for the management of patients with gabapentin-refractory peripheral neuropathic pain in primary-care settings under real-life conditions of care. Our data show that patients who were switched to pregabalin, either as monotherapy or in combination with other analgesics, showed substantial and clinically relevant improvements in relieving pain and related symptoms.