Oxybutynin, an anticholinergic commonly used to treat urinary incontinence, may provide breast cancer survivors with an alternative treatment option for hot flashes, according to new research presented at the 2018 San Antonio Breast Cancer Symposium.
Certain treatments for hot flashes, such as hormone replacement therapy, are generally not recommended for breast cancer survivors, as it carries a risk for cancer recurrence, blood clots or stroke. The double-blind study (ACCRU study SC-1603; N=150) compared oxytbutynin to placebo for improving patients’ quality of life. Included patients had experienced ≥28 hot flashes per week for over a month; 62% were taking tamoxifen or an aromatase inhibitor for the study period. They were randomized to receive oxybutynin 2.5mg, oxybutynin 5mg, or placebo twice daily over 6 weeks.
Preliminary results found that the women in both oxybutynin groups had decreases in hot flashes vs the placebo group. Oxybutynin-treated women experienced decreased interference of hot flashes in their work, social/leisure activities, and sleep as well as improvement in overall quality of life. The results were based on patient completed questionnaires, which were completed daily or weekly. The study was not powered to test doses of oxybutynin doses against each other.
“We were surprised by the rapidity of the response and the magnitude of the effect, considering the relatively low dose of the drug,” said Dr Leon-Ferre of Mayo Clinic, who lead the research, which was funded by the Breast Research Foundation. He stated that the possible long-term side effects of oxybutynin – including cognitive decline – should be further researched.
For more information visit ClinicalTrials.gov.