HORMONE REPLACEMENT THERAPY

In the past, hormone replacement therapy used to be commonly prescribed in women with severe menopausal symptoms, for the treatment of these symptoms as well as for their beneficial effects on osteoporosis, coronary heart disease and colorectal cancer.

However, in recent years, the use of HRTs has decreased significantly due to the findings of a very large study, called the Women's Health Initiative (WHI).

THE WOMEN'S HEALTH INITIATIVE (WHI) STUDY

The Women's Health Initiative (WHI) Study is a very large randomised controlled trial on one combination of HRTs. Conjugated equine estrogen 0.625mg plus medroxyprogesterone acetate 2.5 mg was compared against a placebo in 16,608 healthy postmenopausal women aged between 50 to 79 years, with an intact uterus from 40 North American centres over a planned 8.5 years. One of the study's components examined the role of HRT in the prevention of major degenerative diseases (cardiovascular disease, osteoporosis and cancer).

This component of the WHI Study was stopped prematurely on 31st May 2002, after 5.2 years by the data and safety monitoring board, due to an increased risk of invasive breast cancer, cardiovascular disease, strokes and pulmonary embolism. Reduction of risks were observed in endometrial cancer, hip fractures and colorectal cancers. Since the overall health risks exceeded the benefits, it was concluded that combined estrogen-progesterone is probably only suitable for short term treatment of early menopausal women with significant menopausal symptoms. In general, menopausal symptoms will resolve within 5 years spontaneously.

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UNDERSTANDING THE ROLES OF ESTROGEN & PROGESTERONE

Estrogen and Progesterone and produced by the ovaries in the premenopausal woman, and they work together to thicken the lining of the uterus (the endometrium), to prepare it for possible implantation of a fertilized egg.

As a woman reaches menopause, the lowered and fluctuating levels of estrogen cause the typical menopausal symptoms such as hot flushes.  Estrogen also influences how the body uses calcium, and low levels of estrogen results in increased rates of bone loss, leading to osteoporosis.  Estrogen also helps maintain healthy cholesterol levels and keeps the vaginal membranes moist and healthy.  Low levels of estrogens mean that cholesterol levels, as well as the corresponding risk of cardiovascular disease, increases after menopause.   The vaginal mucous membranes also become dry following menopause.

Progesterone reduces the risk of endometrial cancer.  Estrogen, if taken alone (without progesterone) in women with an intact uterus, would increase her risk of endometrial cancer.  In women who have had a hysterectomy (removal of the uterus), estrogen can be taken on its own.

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TYPES OF HRT AVAILABLE

Both estrogen-only and estrogen in combination with progesterone HRT preparations are available.  They may be in oral, transdermal or topical forms.

Estrogen-only replacement therapy is used only in women who have had their uterus removed.  In women with an intact uterus, the combination forms should be taken instead, either in a cyclical fashion (in which there will be regular withdrawal bleeding) or in a continuous fashion (in which there will be no bleeding).

Women with conditions such as a history of breast and endometrial cancer, abnormal vaginal bleeding, clotting disorders, history of stroke and liver disease, should generally not be on HRTs.

Speak to your doctor about your suitability of starting HRT if you have severe menopausal symptoms.

SYSTEMIC THERAPY

Estrogen-Only (Oral Preparations)

• Conjugated Equine Estrogen (Premarin)
• Estradiol (Estrofem)
• Estradiol Valerate (Progynova)

Estrogen-Only (Transdermal Preparations)

• Estradiol patch (Estraderm)
• Estrogel
• Estradiol Hemihydrate (Estreva gel)

Cyclical Combined Therapies (oral)

• Estradiol valerate and norgestrel (Progyluton)
• Estradiol valerate and cyproterone aceate (Climens)
• Conjugated equine estrogen and norgestrel (Prempak-C)
• Conjugated equine estrogen and medroxyprogesterone acetate (Premelle cycle 5)
• Estradiol and dydrogesterone (Femoston)
• Estradiol and norethisterone acetate (Trisequens)

Continuous Combined Therapies (oral)

• Conjugated equine estrogen and medroxyprogesterone acetate (Premelle 5 or Premelle 2.5)
• Estradiol and norethisterone acetate (Kliogest or Activelle)

LOCAL THERAPY

These hormonal preparations are used in postmenopausal women with symptoms isolated to the urogenital tract.

• Estradiol pessary (Vagifem)
• Conjugated equine estrogen cream (Premarin cream)
• Colpotrophine pessary
• Colpotrophine cream
• Estradiol ring (Estring)

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RISKS AND BENEFITS OF HRT

HRT & Menopausal Symptoms:

HRT is effective in the treatment of menopausal symptoms (in particular, vasomotor symptoms, vaginal dryness and urinary symptoms), thus improving the quality of life in women who suffer from significant symptoms.

HRT & Osteoporosis:

HRT reduces the risk of osteoporosis and its subsequent fractures. However, in view of the associated risks of HRT, alternatives such as bisphosphonates should be used instead.

HRT & Colorectal Cancer:

HRT reduces the incidence of colorectal cancer, however, combination HRT should not be used sole for this purpose due to its associated long term risks.

HRT & Coronary Heart Disease:

Current evidence has not demonstrated any benefit in use of HRT in reducing the risk of coronary heart disease.

HRT & Dementia:

There is no evidence to suggest that HRT improves cognition or protects against dementia.

HRT & Breast Cancer:

Long term HRT use (more than 4 years) is associated with a small but significant increase in risk of invasive breast cancer. The breast mammographic changes on that occur with HRT use may also hinder the diagnosis of breast cancer.

HRT & Endometrial Cancer:

Combination HRT has been shown to reduce the risk of endometrial cancer.

HRT, Deep Vein Thrombosis & Pulmonary Embolism:

Combination HRT use has been associated with significantly increased risk of deep vein thrombosis and pulmonary embolism.

HRT & Stroke:

Combination HRT use has been associated with a small increase in ischaemic strokes.

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The article above is meant to provide general information and does not replace a doctor's consultation. 
Please see your doctor for professional advice.