Oral clonidine in postmenopausal patients with breast cancer experiencing tamoxifen-induced hot flashes: A University of Rochester cancer center community clinical oncology program study

Background: Hot flashes are the most frequently reported side effect of tam oxifen treatment. Although hormones are an effective treatment, their safet y is questionable in women with breast cancer. It is therefore important to evaluate nonhormonal treatments for hot flashes. Objective: To evaluate the effectiveness of oral clonidine for control of h ot flashes associated with tamoxifen therapy in postmenopausal women with b reast cancer. Design: Randomized, double-blind, placebo-controlled clinical trial. Setting: University of Rochester Cancer Center Community Clinical Oncology Program. Patients: 194 postmenopausal women with breast cancer who were receiving ad juvant tamoxifen therapy. Intervention: Oral clonidine hydrochloride, 0.1 mg/d, or placebo for 8 week s. Measurements: In a daily diary, patients recorded number, duration, and sev erity of hot flashes and overall quality-of-life score (on a 10-point scale ) during a 1-week baseline period and during the 4th, 8th, and 12th weeks o f the study. Results: Patients in the placebo and treatment groups were similar in age, duration of tamoxifen use, reported frequency and duration of hot flashes a t baseline, and dropout rates. One hundred forty-nine patients completed 12 weeks of follow-up. The mean decrease in hot flash frequency was greater i n the clonidine group than in the placebo group after 4 weeks of treatment (37% compared with 20% [95% CI for difference, 7% to 27%]) and 8 weeks of t reatment (38% compared with 24% [CI for difference, 3% to 27%]). Patients r eceiving clonidine were more likely than patients receiving placebo to repo rt difficulty sleeping (41% compared with 21%; P = 0.02). A significant dif ference was seen in the mean change in quality-of-life scores (0.3 points i n the clonidine group compared with -0.2 points in the placebo group; P = 0 .02) at 8 weeks, although the median difference was 0 in both groups. Conclusion: Oral clonidine, 0.1 mg/d, is effective against tamoxifen-induce d hot flashes in postmenopausal women with breast cancer.