Tibolone: A Unique Version of Hormone Replacement Therapy

OBJECTIVE: To review the pharmacology, pharmacokinetics, efficacy, and safety of tibolone in the treatment of menopausal symptoms and the prevention of osteoporosis. DATA SOURCES: Information was obtained from a MEDLINE search (1966-July 2003) and from Organon International. The bibliographies of reviewed literature were searched for additional studies. STUDY SELECTION AND DATA EXTRACTION: Studies and review articles evaluating tibolone were evaluated. Since tibolone has been available for many years in Europe and has an extensive literature base, this review emphasizes information from studies published after 1995. DATA SYNTHESIS: Tibolone possesses estrogenic activity and is effective for treating the symptoms and osteoporosis associated with menopause. While the impact of tibolone on the risk of breast cancer or cardiovascular and thromboembolic events is not well defined, its unique pharmacologic profile may provide a safer alternative to traditional hormone replacement therapy. Although widely used for many years in other countries, tibolone has not been approved for use in the US. CONCLUSIONS: Results of recent trials have led to questions regarding the safety of established hormone replacement therapies in peri- and postmenopausal women. Tibolone appears to be an attractive alternative to these traditional regimens. Additional studies will determine whether the promise of increased safety with tibolone will be realized.