These retrospective analyses of daily mean
pain scores from nine placebo-controlled trials of
pregabalin at 150, 300, or 600 mg/day (
pregabalin, n = 1205; placebo, n = 772) examined time to significant reduction of
pain during the first 2 weeks of treatment of painful diabetic
peripheral neuropathy and
postherpetic neuralgia. Time to onset of reduction in
pain-defined as the first day for which patients treated with
pregabalin had significant reductions (P < 0.05) in mean
pain score compared with the placebo group for that day and the subsequent day-was calculated for all treatment groups demonstrating statistically significant reduction in
pain at trial end point. The time to a 1-point or greater improvement in mean
pain score was measured for each patient who was a responder at end point (30% or greater improvement in mean
pain score). In seven of the nine trials (representing 11 of 14
pregabalin arms), significant reduction in
pain was achieved at end point. The time to onset for reduction in
pain was treatment Day 1 or 2 in nine of these successful treatment arms. Individual responder analysis confirmed that responders in the
pregabalin groups reported a 1-point or greater
pain reduction earlier than responders in placebo groups (P < 0.0001). However, this analysis is not a direct estimate of the likelihood that an individual patient would experience noticeable
pain relief by the end of the second day. Overall, for patients who will respond to
pregabalin, statistically significant and sustained reduction of
pain associated with diabetic
peripheral neuropathy and posttherapeutic
neuralgia occurs early, usually by the end of 2 days of
pregabalin treatment.