Successful Treatment of Unscheduled Uterine Bleeding During Transdermal Menopausal Hormone Therapy Combined With Bazedoxifene

Abnormal uterine bleeding and withdrawal bleeding are noted as crucial causal factors for dropout of postmenopausal women during menopausal hormone therapy (MHT). We report the potential for treatment of unscheduled uterine bleeding during transdermal MHT by switching to transdermal 17-beta estradiol (TDE₂) and bazedoxifene acetate (BZA) (TDE₂/BZA) and evaluate the side effects of this treatment on the recurrence of climacteric symptoms in the five reported patients. Five postmenopausal women were treated with estrogen-progestin therapy (EPT) which included TDE₂ and progestin formulation for MHT. The progestin formulation was replaced with BZA, a selective estrogen receptor modulator, due to unscheduled uterine bleeding. Four of five postmenopausal women were evaluated in terms of estrogen dynamics and recurrence of climacteric symptoms. In all cases examined in this report, unscheduled uterine bleeding resolved within one month. In two of four patients in whom climacteric symptoms recurred, their serum estradiol levels were surprisingly elevated three months after the start of TDE₂/BZA. This is the first report, to our knowledge, of the successful treatment of unscheduled uterine bleeding by TDE₂/BZA during MHT and a suggested correlation between estrogen dynamics and concomitant recurrence of side effects caused by TDE₂/BZA.