Oxybutynin Chloride in Managing Hot Flashes

PRIMARY OBJECTIVES: I. To determine whether oxybutynin chloride (oxybutynin) can diminish hot-flash activity in women with a history of breast cancer or in women who have a concern about taking estrogen for fear of breast cancer. SECONDARY OBJECTIVES: I. To perform a dose-response evaluation of two oxybutynin doses. II. To determine the toxicity of oxybutynin in the study population. III. To assess the impact of hot-flash activity on overall quality of life and to examine whether oxybutynin can diminish this impact on quality of life. OUTLINE: Patients are randomized into 1 of 4 groups. GROUP I (LOW-DOSE OXUBUTYNIN CHLORIDE): Patients receive lower dose oxybutynin chloride orally (PO) twice a day (BID) on days 8-49 in the absence of unacceptable toxicity. GROUP II (LOW-DOSE PLACEBO): Patients receive lower dose placebo PO BID on days 8-49 in the absence of unacceptable toxicity. GROUP III (HIGH-DOSE OXUBUTYNIN CHLORIDE): Patients receive lower dose oxybutynin chloride PO BID on days 8-14 and higher dose oxybutynin chloride on days 15-49 in the absence of unacceptable toxicity. GROUP IV (HIGH-DOSE PLACEBO): Patients receive lower dose placebo PO BID on days 8-14 and higher dose placebo on days 15-49 in the absence of unacceptable toxicity.