New developments in HRT: low-dose therapy

Abstract

Hormone therapy for postmenopausal women has been available for over 60 years. Never during all these years have its merits and potential risks come under such scrutiny as in the past 2‐3 years. The culmination or premature termination of large randomised control trials and one large observational study have partly contradicted some of the previously accepted benefits. Since oral conjugated equine oestrogens were first produced, many other routes of administration have been introduced and their relative merits debated. Much recent emphasis, especially from regulatory authorities, has been on limiting the duration and, in particular, the dose of both oestrogen and progestogen. Traditionally, doses of 0.625‐1.25 mg conjugated equine oestrogens and 2 mg estradiol were considered necessary for adequate symptom control and bone protection. Now much lower doses have been shown to be effective and progestogen has been shown to have a further additive effect. Progestogen is given solely to protect the endometrium from the proliferative effects of oestrogen, so it is logical to give this direct to the endometrial cavity by an intrauterine system. A smaller experimental version of the widely used levonorgestrel‐releasing intrauterine system may provide a low‐dose alternative for progestogen administration.