Mirtazapine is in a class of medications called antidepressants. It has also been used as an antianxiety medication, antiemetic, and appetite stiumulant. It works by enhancing adrenergic and serotonergic neurotransmitter activity in the brain. Mitrazapine is also an antagonist of 5-HT3 and histamine receptors. Mirtazapine comes as a tablet and as a disintegrating tablet to take by mouth. As with other antidepressants, it may take time to have effects and may cause withdrawal symptoms on discontinuation. Mirtazapine has been evaluated for anorexia, CINV, depression, sleep-wake disturbance, and hot flashes.
Effectiveness Not Established
Research Evidence Summaries
Biglia, N., Kubatzki, F., Sgandurra, P., Ponzone, R., Marenco, D., Peano, E., & Sismondi, P. (2007). Mirtazapine for the treatment of hot flushes in breast cancer survivors: A prospective pilot trial. Breast Journal, 13, 490–495.doi:10.1111/j.1524-4741.2007.00470.x
The sudy evaluated the efficacy and safety of mirtazapine to reduce hot flashes in women with a previous breast cancer and assessed the influence of the same treatment on sleep quality and other menopausal symptoms.
Intervention Characteristics/Basic Study Process:
Treatment was mirtazapine 15 mg/day at bedtime for one week, then 30 mg/day for the next 11 weeks. Primary end point was to compare hot flash score and frequency after 4, 8, and 12 weeks of treatment to the basal values.
The study enrolled 40 consecutive postmenopausal women with a previous history of breast cancer.
It was conducted in an outpatient treatment clinic for menopausal symptoms.
This was a pilot, open-label study.
Sample size was calculated under the assumptions of the detection of a 50% reduction in hot flash frequency, with 80% power at a two-sided alpha level of 0.05. These assumptions, using a dependant samples t-test, required at least 20 evaluable patients. Tools included: Hot flash diary, hot flash score, MRS, PSQI, and the SF 36 Health Survey.
Twenty patients completed the study. After four weeks of treatment, a significant decrease of vasomotor symptoms compared to baseline values was reported. The mean decrease in hot flash frequency was 46.9% and mean reduction in hot flash score was 49%. The benefit increased at week 8 when the mean decreases in frequency and score were 56.5% and 62.16% respectively. The effects remained stable during the last month.
The study was limited by its small sample size. Out of 40 women enrolled in the study 13 (32.5%) withdrew after signing consent and recording basal data and never began therapy; reasons given for withdrawal included were reluctance to take antidepressant drugs or the fear that thedrug may adversely affect cognitive function or cause side effects.
The study should be duplicated in a larger blinded, placebo-controlled trial. There was a possible negative interaction between the antiproliferative effect of tamoxifen on the breast and mirtazapine.