Hormone replacement therapy thromboembolism

Daly E, Vessey MP, Hawkins MM, Carson JL, Gough P, Marsh S (1996) Risk of venous thromboembolism in users of hormone replacement therapy. Lancet 348 977-980... 

Perez-Gutthan S, Garcfa-Rodriguez LA, Castellsague J, Duque-Oliart A (1997) Hormone replacement therapy and risk of venous thromboembolism population based case-control study. Br Med J 314 796-800... 

Gomes MPV, Deitcher SR Risk of venous thromboembolic disease associated with hormonal contraceptives and hormone replacement therapy A clinical review. Arch Intern Med 2004 164 1965. [PMID 15477430]... 

In hormone replacement therapy, the risk of deep vein thrombosis is increased by a factor of 2-4 (35-37). The absolute increase in the treated population as a whole is low, with about one case of venous thromboembolism in 5000 women-years of use of hormone replacement therapy. However, in the subgroup with pre-existing risk factors, such as obesity, varicose veins, smoking, and a prior history of venous thromboembolism or superficial thrombophlebitis, the increase in risk from hormone replacement therapy can be substantial among these women are those with a genetic predisposition to thrombosis, generally due to some form of thrombophilia, such as deficiency of the coagulation inhibitors protein S, protein C, or anti thrombin III. In any of these subjects thrombosis can occur early in hormone replacement therapy. However, this tendency to early occurrence of deep vein thrombosis also seems to be present in all those who take hormone replacement therapy. 

Much of the evidence on the occurrence of thromboembolic complications with oral contraceptives or hormone replacement therapy has been gathered from European or American populations, and it can be helpful to identify data from other parts of the world, where factors such as... 

Whiteman MK, Cui Y, Flaws JA, Espeland M, Bush TL. Low fibrinogen level A predisposing factor for venous thromboembolic events with hormone replacement therapy. Am J Hematol 1999 61(4) 271-3. 

Hoibraaten E, Abdelnoor M, Sandset PM. Hormone replacement therapy with estradiol and risk of venous thromboembolism—a population-based case-control study. Thromb Haemost 1999 82(4) 1218-21. 

Studies and reviews sponsored by the manufacturer of tibolone have over many decades argued that, as one reviewer puts it, tibolone may provide a safer alternative to traditional hormone replacement therapy , but even this review adds that the impact of tibolone on the risk of breast cancer or cardiovascular and thromboembolic events is not well defined (2). Bearing in mind that these are precisely the questions that have cast a shadow over other forms of hormone replacement therapy, this is a serious defect in the evidence about the drug s safety it is possible that the extent of use of tibolone has been insufficient to provide well-documented answers. 

Douketis J. Hormone replacement therapy and risk for venous thromboembolism what s new and how do these findings influence clinical practice Curr Opin Hematol. 2005 12 395-400. 

Wu O, Robertson L, Langhorne P, et al. Oral contraceptives, hormone replacement therapy, thrombophilias and risk of venous thromboembolism a systematic review. The Thrombosis Risk and Economic Assessment of Thrombophilia Screening (TREATS) Study. Thromb Haemost. 2005 94 17-25. 

Oral contraceptives containing oestrogen and postmenopausal hormone replacement therapy predispose to thromboembolism (see p. 724). 

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