An Effective Medicine for Hot Flashes in Women with Breast Cancer: Oxybutynin

One of the most important problems arising in patients after breast cancer treatment is hot flashes . This adverse effect may be associated with chemotherapy-induced menopause or may develop because of anti-estrogen medicines. Hot flashes can impair sleep quality, cause difficulty working and sexual problems, reducing quality of life .

In the figure above, the currently available medical treatment options for hot flashes are summarized.

What Is Oxybutynin?

Oxybutynin, from the anticholinergic group of medicines, is an active substance with muscle spasm-relieving properties. It is known on the market as Uropan ; syrup and tablet forms are available, and a transdermal form (a patch applied to the skin) has recently entered the market. In particular, for urination problems it is used in both children and adults. One of the medicine's most important effects is reducing sweating.

Previously shown to reduce menopausal complaints in patients who had undergone natural menopause, this medicine was tested in patients with breast cancer for the first time. The study results were presented on day 3 of the San Antonio Breast Cancer Symposium.

The study included 150 breast cancer patients, divided into those taking oxybutynin twice daily at 2.5 mg, those taking it twice daily at 5 mg, and placebo (the no-drug arm), making three groups.

Comparing the average frequency of hot flashes showed that both patients taking 2.5 mg and those taking 5 mg benefited significantly from the medicine compared with the placebo group, with a reduction in hot flash frequency.

The most common oxybutynin-related adverse effects were dry eyes and difficulty urinating; in those taking 2,5 mg, constipation occurred, whereas those taking 5 mg experienced diarrhea. However, all these adverse effects were considered manageable.

One important aspect of the study was that %62 of the breast cancer patients were taking tamoxifen or an aromatase inhibitor. The study showed no interaction between oxybutynin and these medicines.

In addition, a separate analysis in the study showed oxybutynin to be more effective than other medicines and methods used for hot flashes.

In the graph above, oxybutynin is compared with other methods used to treat hot flashes. As shown, within approximately 5 weeks, oxybutynin improved hot flash scores by up to % 80.

Use of the previously known medicine oxybutynin appears meaningful for our patients, improving quality of life by preventing hot flashes. However, long-term study results should also be awaited to identify problems that may arise from very prolonged use.

In conclusion, there appears to be no harm in our breast cancer patients suffering from hot flashes trying nonpharmacological approaches such as acupuncture and yoga , particularly because acupuncture's benefit for this adverse effect has been shown in previous studies . For patients not benefiting from complementary medicine approaches, medicines such as venlafaxine or oxybutynin may be considered on their oncologist's recommendation and under their follow-up.

Related Topic:

- What Are the Evidence-Based Complementary Medicine Methods in Breast Cancer?