tamoxifen + tibolone

Tamoxifen + tibolone is a combination of two oral small molecule drugs used experimentally in postmenopausal women, particularly those with a history of breast cancer. Tamoxifen is a selective estrogen receptor modulator (SERM) that acts as an antagonist on estrogen receptors in breast tissue, reducing the risk of recurrence and progression of hormone receptor-positive breast cancer. Tibolone is a synthetic steroid with weak estrogenic, progestogenic, and androgenic activity; it acts as an agonist at the estrogen, progesterone, and androgen receptors via its metabolites. The combination has been studied to manage climacteric symptoms (such as hot flushes) induced by tamoxifen therapy after surgery for early-stage breast cancer. Clinical studies have shown that adding tibolone to tamoxifen can reduce the frequency and severity of hot flushes without significant adverse effects on endometrial safety or short-term recurrence rates over 12 months[1][2][5]. However, larger trials have raised concerns about increased risk of breast cancer recurrence with tibolone use in survivors[6]. This combination is not commercially available as a fixed-dose product but has been investigated in clinical research settings.