• Hot flash reduction by diary scores at 4 weeks
  

• Toxicity by questionnaires at 4 weeks
  

OBJECTIVES:

• Determine the effectiveness of gabapentin in managing hot flashes in men with prostate cancer.
• Determine the response of patients to this drug.
• Determine the toxicity of this drug in these patients.
• Determine the quality of life of patients treated with this drug.

OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients are stratified according to the number of hot flashes per day (2-3 vs 4-9 vs 10 or more) and duration of hot flash symptoms (less than 9 months vs 9 months or more). Patients are randomized to one of four treatment arms.

All patients are observed for 7 days prior to drug administration in order to collect baseline hot flash information.

• Arm I: Patients receive oral gabapentin once daily on days 1-28.
• Arm II: Patients receive oral gabapentin once daily on days 1-7 and twice daily on days 8-28.
• Arm III: Patients receive oral gabapentin once daily on days 1-7, twice daily on days 8-14, and three times daily on days 15-28.
• Arm IV: Patients receive oral placebo on one of three schedules corresponding to arms I-III.

Patients in all arms may continue therapy with gabapentin for an additional 8 weeks.

Quality of life is assessed at baseline, day 28, and at the end of the additional 8 weeks.

Patients are followed at 6, 12, and 24 months.

PROJECTED ACCRUAL: A total of 220 patients (55 per treatment arm) will be accrued for this study within 1 year.

DISEASE CHARACTERISTICS:

• Diagnosis of prostate cancer
• Received or are currently receiving androgen ablation therapy

• Hot flashes for at least 1 month

  • At least 14 times per week and severe enough to require therapeutic intervention

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-1

Life expectancy:

• At least 6 months

Hematopoietic:

• Not specified

Hepatic:

• Not specified

Renal:

• Creatinine < 1.5 times upper limit of normal over the past 2 years

Other:

• No prior allergic or adverse reaction to gabapentin

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• At least 4 weeks since prior antineoplastic chemotherapy
• No concurrent antineoplastic chemotherapy

Endocrine therapy:

• See Disease Characteristics
• At least 4 weeks since prior androgens, estrogens, or progestational agents
• No concurrent androgens, estrogens, or progestational agents
• Concurrent hormonal therapy allowed if on stable dose for at least 4 weeks and plan to continue therapy throughout study

Radiotherapy:

• Not specified

Surgery:

• Not specified

Other:

• No prior gabapentin
• No other concurrent treatment for hot flashes
• Concurrent antidepressants allowed if on stable dose for at least 1 month and plan to continue therapy throughout study