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.

Levetiracetam for the treatment of hot flashes: A pilot study

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Background: Hot flashes affect 75 % to 90 % of women transitioning to menopause and are a major cause of morbidity among breast cancer survivors. Levetiracetam, a popular anticonvulsant, is a centrally active agent that anecdotally appeared to reduce hot flashes in clinical practice. This phase II trial sought to evaluate the efficacy of levetiracetam in reducing hot flashes among women with a history of breast cancer or women who did not wish to take estrogen therapy for fear of an increased risk of breast cancer. Methods: Women who were experiencing bothersome hot flashes (≥ 14 times per week, for ≥ 1 month) were eligible. A single arm pilot study design based on previous work was used with a planned sample size of 30 patients. The patients did not receive any study medication during the first week (baseline week). At the beginning of the second week, patients were started on levetiracetam (500 mg), and were to increase the dose by 500 mg each week to a goal of 1,000 mg twice daily. Hot flash diaries were completed daily. The primary endpoint was hot flash score (frequency times average severity). The change from week 1 (baseline) to week 5, the last treatment week, was analyzed by paired t-test and related Wilcoxon procedures. Results: A total of 30 women were enrolled onto this study in eight months. All patients were eligible. 19 women completed all 4 weeks of the study treatment and provided complete data. After treatment with levetiracetam for 4 weeks, mean hot flash scores were reduced by 57% (95% CI 39%-75%), while mean hot flash frequencies were reduced by 53% (95% CI 38%-68%), reductions being greater than what would be expected with a placebo. There were significant improvements, compared to baseline week data, in sweating, hot flash distress, and satisfaction with hot flash control. Eight subjects stopped the study drug due to treatment related adverse events (grade I/II), with the most frequently reported being somnolence, fatigue and dizziness. Conclusions: While levetiracetam appears to be a promising therapy for the treatment of hot flashes, further study is needed to better substantiate the toxicity and efficacy of this drug before it can be more definitively recommended for use in clinical practice.

No significant financial relationships to disclose.

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]