Gabapentin With or Without Antidepressants in Treating Hot Flashes in Women Who Have Had Breast Cancer or Have Concerns About Taking Hormone Therapy

OBJECTIVES:

• Compare the efficacy of gabapentin with vs without an antidepressant, as measured by the frequency and intensity of hot flashes, in patients with a history of breast cancer or a concern about taking hormonal therapy due to a fear of developing breast cancer.
• Compare adverse events in patients treated with these regimens.
• Correlate a reduction in hot flash scores with improvement in quality of life and related outcomes in patients treated with these regimens.

OUTLINE: This is a randomized, multicenter study. Patients are stratified according to duration of hot flash symptoms (< 9 months vs ≥ 9 months), average frequency of hot flashes per day (2-3 vs 4-9 vs ≥ 10), and antidepressant currently being used (venlafaxine vs paroxetine vs other). Patients are randomized to 1 of 2 treatment arms.

• Arm I: Patients continue to receive the same antidepressant (as before study entry) on weeks 1-5. During weeks 2-5, patients also receive oral gabapentin once daily on days 8-10, twice daily on days 11-13, and then three times daily on days 14-35 in the absence of unacceptable toxicity.
• Arm II: Patients receive gabapentin as in arm I. Patients are tapered off their antidepressant over 7-10 days and remain on gabapentin alone (per arm I schedule).

Patients in both arms complete a hot flash diary at baseline and then daily during study treatment.

Quality of life is assessed at baseline and then weekly during study treatment.

PROJECTED ACCRUAL: A total of 110 patients (55 per treatment arm) will be accrued for this study within 2 years.

DISEASE CHARACTERISTICS:

• History of breast cancer OR a concern about taking hormonal therapy due to a fear of developing breast cancer
• Experiencing bothersome hot flashes, defined as patient-reported occurrence ≥ 14 times per week AND sufficiently severe to prompt desire for additional therapeutic intervention despite current use of an antidepressant

• Currently (≥ 2 weeks) being treated with a stable dose of an antidepressant

• No monoamine oxidase inhibitors or tricyclics
• No current evidence of malignant disease
• Hormone receptor status:

• Not specified

PATIENT CHARACTERISTICS:

Age

• 18 and over

Sex

• Female

Performance status

• ECOG 0-1

Life expectancy

• At least 6 months

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective barrier contraception

PRIOR CONCURRENT THERAPY:

Chemotherapy

• More than 4 weeks since prior antineoplastic chemotherapy
• No concurrent antineoplastic chemotherapy

Endocrine therapy

• More than 4 weeks since prior androgens, estrogens, or progestational agents
• More than 2 weeks since prior dehydroepiandrosterone (DHEA) for treatment of hot flashes
• No concurrent androgens, estrogens, or progestational agents, including oral contraceptives
• No concurrent DHEA for treatment of hot flashes
• Concurrent tamoxifen, raloxifene, or aromatase inhibitor therapy allowed if on a stable dose for at least 4 weeks prior to study entry and during study treatment

Other

• No prior gabapentin
• More than 2 weeks since other prior treatment for hot flashes (e.g., clonidine or Bellergal-S®)
• Concurrent vitamin E or soy supplements allowed if on a stable dose for at least 1 month prior to study entry and during study treatment
• No other concurrent treatment for hot flashes (e.g., clonidine or Bellergal-S®)
• No other concurrent antidepressants