Pregabalin vs. opioids for the treatment of neuropathic cancer pain: a prospective, head-to-head, randomized, open-label study.

Objectives: Neuropathic cancer pain (NCP) is a common manifestation of cancer and/or its treatment. Treatment following the WHO analgesic ladder provides relief for the majority of cancer pain patients; however, concern remains that opioids may be less efficacious for neuropathic pain (NP) compared with nociceptive pain, often necessitating the use of higher doses. Adjuvants, such as pregabalin, have shown to be efficacious for the treatment of NP, although data come mostly from noncancer studies. The comparative efficacy and safety of opioids versus adjuvants has not been studied for NCP. The aim of this study was to directly compare pregabalin versus a strong opioid for the treatment of NCP.

Methods: A total of 120 patients, diagnosed with "definite" NCP, were randomized into two groups and received increasing doses of either oral pregabalin or transdermal fentanyl for 28 days. VAS score, patient satisfaction, need for opioid rescue, and adverse events (AEs) were recorded.

Results: In the pregabalin group, a significantly higher proportion of patients achieved at least 30% reduction in VAS compared with the fentanyl group (73.3%, 95% CI: 60.3%-83.93 vs. 36.7%, 95% CI: 24.5%-50.1%, P < 0.0001, respectively), while the percentage mean change from baseline was also significantly different [46% (95% CI: 39.5%-52.8%) for pregabalin and 22% (95% CI: 14.9%-29.5%) for fentanyl (P < 0.0001)]. Patient-reported satisfaction was more frequent with pregabalin, while AEs and treatment discontinuations were more frequent in the fentanyl group.

Discussion: Prompt use of a neuropathic pain-specific adjuvant, such as pregabalin, in NCP may lead to better control of the neuropathic component, with opioid-sparing effects.