Science

Birth control pill reduces menstrual periods to four a year

Canadian women who want to avoid pregnancy and at the same time reduce the frequency of their menstrual periods will have that option later this year.

Canadian women who want to avoid pregnancy and at the same time reduce the frequency of their menstrual periods will have that option later this year.

Montreal pharmaceutical company Paladin Labs announced Thursday it has received approval from Health Canada to market an oral contraceptive that suppresses menstrual periods for three months at a time.

The pills strike "a balance between the benefits of having fewer periods with the reassurance of still having some periods," the company said in a release.

Company officials say their market research shows Canadian women are open to the idea of reducing the number of their periods. "When given a choice regarding how often they could have a period, the most popular alternative was four times a year (almost 40 per cent of respondents), while only one out of five felt comfortable with complete suppression of their periods."

The contraceptive, to be marketed under the name Seasonale, is a 91-day regimen taken daily as 84 active tablets followed by seven inactive tablets, during which time a woman would have her period. By contrast, oral contraceptive products currently on the market are based on a 28-day regimen, with 21 active pills and seven inactive tablets.

In U.S. clinical trials that ended in 2002, the company says 1,400 patients between the ages of 18 and 40 took the pill, and there was an extension trial with 300 patients for an additional two years.

The statement said Seasonale was found to be just as effective and safe as traditional oral contraceptives. The most common side effects were inflammation of the nasal passages, headache and intermenstrual bleeding or spotting.

The pills, available in the U.S. since 2003,are expected to beon the Canadian marketsome time in the last quarter of this year.

Seasonale is the first and only extended-cycle oral contraceptive pill available in Canada, but it's not the only option for Canadian women who want to avoid periods.

Depo-Provera, an injection of a hormone called progestin, prevents a woman's ovaries from releasing eggs. The injections are given every 12 weeks to prevent pregnancy.

Dr. Edith Guilbert, who works in a family planning clinic in University Hospital at Laval University in Quebec City, said menstrual periods stop in 50 to 60 per cent of women taking Depo-Provera shots after one year, and in 75 to 80 per cent of women taking the shots after two years.

Guilbert, who has done some consulting work for Paladin Labs, said Thursday the new pill may be welcomed by women who are annoyed by side-effects experienced during their periods, such as migraine headaches, pain and tiredness.

She noted that many women already avoid periods by continuously taking 21-day packs of birth control pills without stopping for seven days or taking any placebo pills to allow for monthly bleeding.

The Society of Obstetricians and Gynaecologists of Canada will release a clinical guideline on continuous-use and extended-use oral contraceptives this month, a spokesman said.

It will be published in the Journal of Obstetrics and Gynaecology Canada, and provide guidance to Canadian health-care professionals on the clinical use of these new contraceptives.

With files from the Canadian Press

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