Evidence for Clonidine in Menopausal Vasomotor Symptoms
Based on the available evidence, at least 4 studies have demonstrated clonidine's effectiveness in reducing vasomotor symptoms of menopause, including 2 randomized controlled trials in breast cancer survivors and 2 studies in healthy postmenopausal women. 1
Study Count and Quality
The NCCN guidelines specifically reference 4 distinct studies showing clonidine's benefit for menopausal hot flashes:
- Two small studies in healthy postmenopausal women demonstrated that clonidine can reduce hot flashes 1
- Two randomized controlled trials (RCTs) in breast cancer survivors showed clonidine reduces hot flash frequency and severity in postmenopausal women taking tamoxifen 1
Additional Supporting Evidence
A systematic evidence-based review identified 11 randomized controlled trials involving clonidine for menopausal vasomotor symptoms, concluding there is evidence that clonidine may be beneficial in treating these symptoms in some women 2
Historical Studies
- A 1974 multicentre, placebo-controlled, double-blind, crossover study of 100 patients showed clonidine had a statistically highly significant effect in controlling the number, severity, and duration of menopausal flushes 3
- A 1980 multicentre, randomized, placebo-controlled, double-blind crossover study of 66 patients found clonidine (0.05 mg twice daily) reduced frequency of attacks significantly more than placebo, with 78% of patients experiencing reduced frequency 4
Clinical Context
While clonidine demonstrates efficacy, comparative studies suggest venlafaxine may have a faster effect but is less well tolerated than clonidine 1. The typical dose used is 0.1 mg/day (oral or transdermal), though side effects include sleep difficulties, dry mouth, fatigue, dizziness, and nausea 1, 5.
The evidence base includes at minimum 4 studies cited in current guidelines, with a broader systematic review identifying 11 RCTs, making clonidine a well-studied nonhormonal option for menopausal vasomotor symptoms.