A phase III randomized, double-blind, placebo-controlled trial of gabapentin in the management of hot flashes in men (N00CB)

INTRODUCTION

Hot flashes represent a significant problem in men undergoing androgen deprivation therapy.

MATERIALS AND METHODS

Via a prospective, double-blind, placebo-controlled clinical trial, men with hot flashes, on a stable androgen deprivation therapy program for prostate cancer, received a placebo or gabapentin at target doses of 300, 600, or 900 mg/day. Hot flash frequencies and severities were recorded daily during a baseline week and for 4 weeks while the patients took the study medication.

RESULTS

In the 214 eligible patients who began the study drug on this trial, comparing the fourth treatment week to the baseline week, mean hot flash scores decreased in the placebo group by 4.1 units and in the three increasing dose gabapentin groups by, 3.2, 4.6, and 7.0 units. Comparing the three combined gabapentin arms to the placebo arm did not result in significant hot flash differences. Wilcoxon rank-sum P values for change in hot flash scores and frequencies after 4 weeks of treatment were 0.10 and 0.02, comparing the highest dose gabapentin arm to the placebo arm, respectively. The gabapentin was well tolerated in this trial.

CONCLUSION

These results support that gabapentin decreases hot flashes, to a moderate degree, in men with androgen ablation-related vasomotor dysfunction.

Gabapentin for hot flashes in men: NCCTG trial N00CB

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Background: Hot flashes can be a major problem in men with prostate cancer; effective non-hormonal options are needed. Methods: A four-arm, double-blinded, placebo-controlled randomized trial was developed to evaluate gabapentin for hot flashes. Men with bothersome hot flashes (at least 14/week) related to androgen deprivation therapy were randomized to receive either a placebo or gabapentin doses of 300 mg qd, 300 mg bid or 300 mg tid; men were treated for 4 weeks. Hot flashes numbers and scores (hot flash number times mean severity) were measured using a validated daily hot flashes diary. A one-week baseline period preceded initiation of study tablets. The primary endpoint was the average intrapatient difference in hot flash score between baseline and treatment termination. With the planned sample size of 50 evaluable patients per arm, the study provided 80% power to detect a difference in change from baseline at 4 weeks between each gabapentin arm and the placebo arm of 1.3 hot flashes per day or 3.3 points in hot flash score. Results: 223 patients were randomized between 12/21/2001 and 11/10/2006. The study arms were well balanced. The following table illustrates the percentage of baseline hot flash scores and frequencies during the fourth treatment week, compared to the baseline week for 179 eligible patients, utilizing the data available at time of this abstract preparation. Patients receiving 900 mg/d dose of gabapentin also reported significantly less hot flash distress and more hot flash control satisfaction than did the placebo group. The gabapentin was remarkably well tolerated, without any statistically significantly worse patient-reported side effects on the gabapentin arms. Conclusion: Gabapentin at the 900 mg/d dose can reduce hot flashes, in men receiving androgen deprivation therapy for prostate cancer.

No significant financial relationships to disclose.

[Table: see text]