Published: 30 September 2002


Hormone Replacement Therapy - Letter to Healthcare Professionals

Information on this subject has been updated. Read the most recent information.

This letter will be posted to all doctors and pharmacies on Wednesday 2 October.

Medsafe letterhead

30 September 2002





Dear Health Professional

In July 2002, the Women's Health Initiative Study1 published results, summarised below, demonstrating that the risks of routine combined oestrogen and progestogen hormone replacement therapy (HRT) outweighed the benefits.

Table 1. Summary of incidence of adverse events based on results from the WHI study. Data derived from women aged 50 to 79 years, after an average follow-up of 5.2 years.

Adverse Event Relative Risk
HRT vs placebo at 5.2 years
(95% CI)
Change in number of
adverse events per 10,000
women in one year
Breast cancer 1.26 (1.00-1.59) 8 extra
Heart disease 1.29 (1.02-1.63) 7 extra
Stroke 1.41 (1.07-1.85) 8 extra
Pulmonary embolism 2.13 (1.39-3.25) 8 extra
Colorectal cancer 0.63 (0.43-0.92) 6 fewer
Hip fracture 0.66 (0.45-0.98) 5 fewer

Following publication of the WHI study, the New Zealand Guidelines Group and the Medicines Adverse Reactions Committee (MARC) conducted independent reviews of the literature on the risks and benefits of combined HRT. The Guidelines Group key messages are enclosed (see link below) and are supported by the MARC.

On completion of its review the MARC concluded that:

  • Combined HRT should normally be used only where menopausal symptoms are disruptive to the quality of life of the woman;
  • HRT should not be used for the primary or secondary prevention of coronary heart disease or stroke;
  • In most circumstances, the risks of long term treatment outweigh the benefits; and combined HRT should not be used for longer than 3-4 years;
  • Oestrogen-only HRT increases the risk of breast cancer and venous thromboembolism to a similar extent as combined HRT;
  • All prospective and current users of HRT should be advised of the risks and benefits of oestrogen and progestogens;
  • The need for continued treatment with HRT should be reviewed at the woman's next visit to her General Practitioner and thereafter on a yearly basis.

The MARC advice to limit the duration of HRT use raises questions about the role of HRT in the management of osteoporosis. The Committee will convene an expert advisory panel to advise Medsafe on this issue. The outcome will be made available to PHARMAC for their review of HRT medicines. Further advice and information will be published in Prescriber Update.

Yours sincerely

Stewart S Jessamine
Principal Technical Specialist


  1. Writing Group for the Women's Health Initiative (WHI) Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: Principal results from the WHI randomized controlled trial. JAMA 2002;288:321-333.

Level 18, Grand Plimmer Tower, 2-6 Gilmer Terrace, P O Box 5013, Wellington.  Phone (04) 496 2000 Fax (04) 496 2229

Link to New Zealand Guidelines Group - Hormone Replacement Therapy Update - Key Messages (September 2002)
(This is a 325KB PDF file which requires Adobe Acrobat Reader to enable viewing - download Adobe Acrobat Reader)


Hide menus
Show menus
0 1 2 4 5 6 7 9 [ /