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

Abstract

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.

Figure 1.

Consort diagram of patient flow in this trial.

Figure 2.

Mean changes from baseline for hot flash scores (A) and frequencies (B) for all study arms.

Figure 3.

Median changes from baseline in hot flash distress, for each study arm (higher scores are better, on a total scale of 100 points).

Figure 4.

Cross study comparisons of data from two studies of gabapentin in women [16, 17] and the current one in men. Error bars represent 95% confidence intervals.