Women to get warning on contraceptive injection

New warnings will be attached to the use of the depo provera contraceptive injection after American research found it was associated with changes in bone density, putting women at greater risk of osteoporosis.

The United States Food and Drug Administration has issued a "black box" warning about long-term use of the drug after research suggested it might lead to significant loss of bone density.

The label states that bone thinning is greater with longer usage of the drug and might not be completely reversible. It should only be used as a long-term birth control method if other contraceptives are inadequate.

Pharmac figures show about 6700 women use the depo provera injection here.

Pfizer New Zealand general manager Mark Crotty said prescribing information already contained a warning that use of depo provera could be a risk factor for developing osteoporosis. More research on women aged 25-35 and adolescents had resulted in the revised warning.

Mr Crotty said the company would tell all healthcare workers of the findings.

Jo Fitzpatrick, director of Women's Health Action, said it was vital women were aware of the risks, particularly younger women as those were the years when bone density was "laid down".

Women's health advocate Sandra Coney raised concerns about the issue 14 years ago after a small New Zealand study found women using the drug for more than five years lost substantial amounts of bone density in the spine and hip, increasing their risk of osteoporosis.

Ms Fitzpatrick said depo provera, which had been available here since 1968, had attracted criticism from women's health groups around the world.

Women who had used depo provera now or in the past could make lifestyle changes to offset the risk, such as getting plenty of exercise and monitoring their calcium and vitamin D intake, she said.

Dr Stewart Jessamine, senior medical adviser for the Ministry of Health's drug safety agency, Medsafe, said it had asked for additional warnings to be added to the prescribing information and the consumer information leaflet.

 

DEPO PROVERA

* About 39,000 women in this country use the depo provera injection.

* The injection has been available here since 1968 but has been criticised by women's health groups around the world.

* Some women have had side-effects such as anaphylactic shock, prolonged menstruation or no menstruation, sudden partial loss of vision, and fatigue.