Analgesic efficacy of pregabalin in acute postmastectomy pain: placebo controlled dose ranging study.

STUDY OBJECTIVE: We hypothesized that oral administration of a single dose of pregabalin 2 hours before modified radical mastectomy (MRM) would produce dose-related reduction in postoperative opioid consumption.

DESIGN: Prospective randomized controlled clinical trial.

SETTING: Postanesthesia care unit.

PATIENTS: One hundred twenty adult women scheduled for unilateral (MRM) with axillary evacuation.

INTERVENTIONS: Patients were randomized to receive either, placebo capsule, pregabalin 75 mg, pregabalin 150 mg, or pregabalin 300 mg.

MEASUREMENTS: The assessment parameters were the postoperative analgesic effect using visual analog scale (VAS) pain scores, the subsequent 24-hour morphine consumption, and the systemic adverse effects of pregabalin doses.

MAIN RESULTS: The VAS score at rest and movement was significantly decreased only in group P300 and group P150 in comparison to group P0 and group P75 at 0 hour (P<.01). The median (interquartile range) consumption of morphine in the first postoperative 24 hours was significantly decreased in group P300 in comparison to group P0 and group P75 (P300 vs P0: 6.5 [5-6.5] vs 20.5 [15.8-20.5] [P<.001]; P300 vs P75: 6.5 [5-6.5] vs 20 [14-20] [P<.001]), but there was no significant difference between group P300 and group P150. In addition, there was a significant decrease in consumption of morphine in group P150 in comparison to group P0 and group P75 (P150 vs P0: 7 [5-7] vs 20.5 [15.8-20.5] [P<.001]; P150 vs P75: 7 [5-7] vs 20 [14-20] [P<.001]). There were statistical significant increase in dizziness and blurred vision in group P300 in comparison to other groups (P<.05).

CONCLUSIONS: A single preoperative oral dose of pregabalin 150 mg is an optimal dose for reducing postoperative pain and morphine consumption in patients undergoing MRM.