HRT originally consisted of oestrogen only; progestogen was added later to protect women from the increased risk of cancer of the lining of the womb if oestrogen is used alone.
What is HRT?
Hormone Replacement Therapy is designed to replace the hormones which the ovaries stop producing at the menopause. Taking replacement oestrogen helps to prevent menopausal symptoms such as hot flushes, vaginal dryness and night-sweats.
There are many formulations and combinations of HRT available on the market here. It can be taken orally, through a skin patch, in the form of a pessary or by implant. Some forms of HRT involve taking a continuous dose of oestrogen and progestogen; other tablets have a daily dose of oestrogen but include progestogen for 10 to 14 days of each month.
Who takes it and why?
HRT is mainly used by women over the age of 50. It is estimated that 10-12 per cent of women in this age group in the Republic take HRT. It is also prescribed in women who have had their ovaries and womb removed or who experience early menopause for other medical reasons.
The principal reason for most women taking HRT is to alleviate menopausal symptoms in the short term. More prolonged use helps prevent osteoporosis [thinning of the bones]. Based on initial trials in the 1990s, doctors had considered long-term HRT useful in the prevention of heart disease and stroke, but this has never been formally licensed by the Irish Medicines Board.
What are the side-effects?
HRT can cause nausea, ankle-swelling, breast tenderness, headaches, abdominal bloating, weight gain and mood swings. Its most serious adverse effects include the risk of deep vein thrombosis, breast cancer, heart disease and cancer of the womb.
Are there alternatives?
In conventional medicine, there are two alternatives to oestrogen and progestogen. Tibilone is a synthetic steroid with an oestrogen/progestogen-like activity. It helps symptoms such as flushing and sweats as well as preventing osteoporosis.
A new group of drugs called selective oestrogen receptor modulators [SERMs] help prevent thinning of the bones but will not alleviate unpleasant menopausal symptoms. Phytoestrogens are plant nutrients contained in almost all fruit, vegetables and cereals. Japanese women who eat a diet rich in soya products, rice, seaweeds and green tea have high levels of isoflavones [a class of phytoestrogen] and do not suffer symptoms such as hot flushes.
While there is scientific evidence to back up the claims of tibilone, SERMs and phytoestrogen, other complementary therapies have never been subjected to clinical trials. Nevertheless, therapists recommend herbal products to alleviate hot flushes and night-sweats as well as homeopathic remedies such as belladonna and sepia. Natural cream made from the Mexican wild yam is another popular alternative.