Abstract

OBJECTIVE to evaluate the efficacy, safety, and tolerability of pregabalin across the effective dosing range; to determine differences in the efficacy of TID and BID dosage schedules; and to use time to event analysis to determine the time to onset of a sustained therapeutic effect using data from 7 trials of pregabalin in painful diabetic neuropathy (DPN).

METHODS Data were pooled across 7 double-blind, randomized, placebo-controlled trials using pregabalin to treat painful DPN with dosages of 150, 300, and 600 mg/d, administered TID or BID. Only 1 trial included all 3 of these dosages and TID dosing was used in 4. All studies shared fundamental selection criteria and treatment durations ranged from 5-13 weeks.

RESULTS pooled analysis showed pregabalin significantly reduced pain and pain-related sleep interference associated with DPN (150, 300 and 600 mg/d administered TID vs placebo all P ≤0.007). Only the 600 mg/d dosage showed efficacy when administered BID (P ≤0.001). Pain and sleep interference reductions associated with pregabalin appear to be positively correlated with dosage; the greatest effect was observed in patients treated with 600 mg/d. Kaplan-Meier analysis revealed the median time to onset of a sustained (≥30% at end-point) 1-point improvement was 4 days in patients treated with pregabalin 600 mg/d; 5 days in patients treated with pregabalin 300 mg/d; 13 days in patients receiving pregabalin 150 mg/d; and 60 days in patients receiving placebo. The most common treatment-emergent adverse events were dizziness, somnolence and peripheral edema.

CONCLUSIONS Treatment with pregabalin across its effective dosing range is associated with significant, dose-related improvement in pain in patients with DPN.