oxybutynin treatment helped reduce the frequency and intensity of hot flashes in women who were not taking hormone replacement, including survivors of the chest, according to a study presented at the Symposium on Breast Cancer in San Antonio in 2018, held on 4-8 December.
According to the study's lead author, Robert A. Leon-Ferre, MD, assistant professor of oncology at the Mayo Clinic in Rochester, Minnesota, the tides, is a common symptom of menopause, may be more severe in patients treated for breast cancer. Several factors contribute to an increase in the severity of the survivors: Chemotherapy can cause early menopause; anti-estrogen drugs, which are the main component of the treatment of breast cancer may enhance tides; and hormone replacement therapy, which is sometimes prescribed for the treatment of hot flushes, is generally not recommended for patients after treatment for breast cancer.
"Hot flashes do not just affect the quality of life; They also may be associated with premature discontinuation of treatment of breast cancer that can increase the risk of recurrence and death from breast cancer, "- said Leon Ferret. "It is therefore important to find effective treatment options for hot flashes."
Previous studies have shown that hot flashes can be reduced by using of oxybutynin, an anticholinergic agent. This type of drug affects the activity of a neurotransmitter in the brain and peripheral nervous system. It is most often used to treat urinary incontinence.
In this study, which is part Academic and Community Cancer Research United (ACCRU), researchers have tried to determine whether oxybutynin was more effective than placebo in the treatment of hot flushes and improving quality of life. The researchers documented 150 women who experienced, at least 28 hot flashes a week for over a month, and which were quite concerned that want to take medication. Sixty-two percent of women took tamoxifen or an aromatase inhibitor for the study.
The women were randomly assigned to receive oxybutynin 2.5 mg twice a day for six weeks (Oxy2,5); 2.5 milligrams twice a day for one week, increasing to 5 mg twice daily (Oxy5) or placebo. Women filled baseline and monthly questionnaires, in which tracks the frequency and severity of hot flushes, whereby figure HF was calculated.
The study showed that patients taking both doses of oxybutynin, there was a decrease of heart failure rates compared with women taking a placebo.
Patients in Oxy2.5 group had a mean change in score HF -10,6, compared to placebo -5.7. They experienced an average of 4.8 fewer hot flashes per day compared to 2.6 hot flashes in women in the placebo group. Side effects for this group included diarrhea, dry mouth, dry eyes, episodes of confusion, and difficulty urinating, but all were mild in severity.
Patients in Oxy5 group had a mean change in score HF -16,9, and they experienced an average of less than 7.5 hot flushes per day. Side effects for this group include constipation, dry mouth, and difficulty urinating. Withdrawal rates due to oxybutynin side effects was low in both groups.
Women in both groups oxybutynin also reported improved work, social activities, leisure, sleep and overall quality of life.
"This study, in addition to the previously published works in this field, states that oxybutynin is an effective drug for the treatment of hot flashes in patients who have relative or absolute contraindications to hormone therapy," - said Leon Ferret. "We were surprised by the speed of reaction and the magnitude of the effect, given the relatively low dose of the drug.
"The fact that a oxybutynin does not affect the metabolism of tamoxifen, is an important factor for survival after breast cancer, as it is believed that some of the most effective non-hormonal methods of treatment of hot flashes can reduce the effectiveness of tamoxifen," - said Leon Ferret.
Leon Ferrer said that since oxybutynin is already available for other indications, doctors can potentially assign it now for other purposes. However, Leon Ferrer said that the main limitation of the study is that it does not consider long-term toxicity of oxybutynin. Previous studies have shown that prolonged use of anticholinergic drugs may be related to the deterioration of cognitive functions. These are the possible side effects should be studied and taken into account when counseling patients, said Leon Ferret.