Oxybutynin Chloride in Managing Hot Flashes

Inclusion Criteria:

• History of breast cancer, ductal breast carcinoma in situ (DCIS), or lobular carcinomain situ (LCIS) (currently without evidence of malignant disease) OR a concern abouttaking estrogen for fear of breast cancer

• Bothersome hot flashes (defined by their occurrence of >= 28 times per week and ofsufficient severity to prompt the patient to seek therapeutic intervention)

• Presence of hot flashes for > 30 days prior to study entry

• Ability to complete questionnaire(s) by themselves or with assistance

• Eastern Cooperative Oncology Group (ECOG) performance status (PS) = 0, 1

• Ability to provide informed written consent

• Life expectancy >= 6 months

• Willing to work with the enrolling institution for follow-up (during the activemonitoring phase of the study)

Exclusion Criteria:

• Any of the following current (=< 4 weeks prior) or planned therapies:

• Antineoplastic chemotherapy (anti-HER2 agents allowed)

• Androgens

• Estrogens (any delivery route)

• Progestogens

• Tamoxifen, raloxifene and aromatase inhibitors are allowed, but patient must havebeen on a constant dose for at least 28 days and must not be expected to stop themedication during the study period

• Selective serotonin reuptake inhibitors (SSRIs)/serotonin?norepinephrine reuptakeinhibitors (SNRIs), when being used for hot flash management or other indicationssuch as depression, is allowed, assuming the dose will remain unchanged for thestudy duration

• Gabapentin/pregabalin, when being used for hot flash management (use for otherindications, such as pain, is allowed, assuming the dose will remain unchangedfor the study duration)

• Clonidine

• Agents with known potent anticholinergic activity; agents with mild-moderateanticholinergic activity are allowed

• Prior use of oxybutynin during the period in which patient has had hot flashes

• Pregnant women

• Nursing women

• History of any of the following contraindications to oxybutynin:

• Uncontrolled gastroesophageal reflux disease (GERD) despite appropriate therapy;if patient has history of GERD, but symptoms are well-controlled with medicaltreatment, patient is eligible

• Ulcerative colitis

• Narrow-angle glaucoma

• Urinary retention

• Hypersensitivity to oxybutynin or any other components of the product

• Current uncontrolled hyperthyroidism

• Coronary heart disease (angina or prior myocardial infarction)

• Congestive heart failure

• Symptomatic cardiac arrhythmias

• Current uncontrolled hypertension

• Myasthenia gravis

• Dementia