Mayo Clinic researchers have found that oxybutynin (Ditropan XL, Janssen Pharmaceuticals, Inc.) helps to reduce the frequency and intensity of hot flashes in women who are unable to take hormone replacement therapy, including breast cancer survivors.
Hot flashes can be more severe in breast cancer survivors than they are in the general population. Factors contributing to this increased severity include exposure to chemotherapy, which may bring on early menopause; antiestrogen drugs; and medications or procedures used to suppress ovary function.
Previous research had suggested that hot flashes may be relieved with oxybutynin, an anticholinergic agent commonly used to treat urinary incontinence. In the current study, researchers aimed to determine whether oxybutynin was more effective than placebo for treating hot flashes and improving patients’ quality of life.
Of the 150 women enrolled in the three-arm trial, 62% were on tamoxifen or an aromatase inhibitor for the duration of the study. Patients in two arms received different dosages of oxybutynin and patients in the third arm received a placebo.
Patients on both oxybutynin doses experienced a decrease in hot flashes compared to those who took the placebo. The women in both oxybutynin arms also reported decreased interference of hot flashes in their work, social activities, leisure activities, sleep, and improvement in their overall quality of life. The researchers were surprised at the speedy response and the magnitude of the effect, especially as the drug was given at a relatively low dose.
In addition, unlike antidepressants, for example, oxybutynin did not interfere with the efficacy of tamoxifen, an important consideration for breast cancer survivors.
The study did not address long-term toxicities of oxybutynin. Previous research indicated that long-term use of this type of drug may be associated with cognitive decline.
Source: Mayo Clinic, December 10, 2018