The efficacy and safety of pregabalin in the treatment of neuropathic pain associated with chronic lumbosacral radiculopathy

We evaluated the efficacy of pregabalin in patients with chronic lumbosacral radiculopathy. This randomized,
controlled, withdrawal trial included five phases: screening (4–18 days); run-in (4–10 days)
to screen out placebo responders; single-blind (28 days) to identify pregabalin responders; double-blind
to randomize responders to pregabalin or placebo (35 days); and final study medication taper (7 days).
The primary endpoint was time to loss of response (LOR) during the double-blind phase (P1-point
increase in pain, discontinuation, or rescue-medication use). In the single-blind phase, 58% of patients
had P30% pain reduction. In the double-blind phase, pregabalin (n = 110) and placebo (n = 107) groups
did not differ significantly in time to LOR. Adverse events caused the discontinuation of 9.9% and 5.6%
of pregabalin-treated and placebo-treated patients, respectively. Most patients with chronic lumbosacral
radiculopathy responded to pregabalin therapy; however, time to LOR did not significantly differ
between pregabalin and placebo. Considering the results of all phases of the study, it is difficult to draw
definitive conclusions from it, suggesting a need for further work to understand the clinical potential of
pregabalin treatment for lumbosacral radiculopathy.