The U.S. government is considering setting higher standards for the Pill – birth control drugs used by millions – saying that newer pills appear to be less effective at preventing pregnancy than those approved decades ago.
The Food and Drug Administration is asking a panel of experts this week whether it should require new contraceptive drugs to meet a standard of effectiveness before they are approved for the market.
More than 60 per cent of U.S. women between the ages of 15 and 44 use some sort of contraception, with 11.6 million choosing birth control pills, according to a 2005 survey by the Guttmacher Institute, a nonprofit research group.
In briefing documents posted to its website, the FDA says newer contraceptives have been less effective – at times, with twice the failure rate – than previous products, most likely because manufacturers have started using lower doses of hormones that stop ovulation.
"The very first pills were very high-dose and carried risks of blood clots and cardiovascular problems that would be unacceptable to most women," said Amy Allina, program director of the National Women's Health Network. "Today most birth control pills are very safe for the vast majority of women.''
The FDA wants to know whether the benefit of that improved safety profile outweighs a slightly increased risk of unwanted pregnancies.
The original birth control pills approved in the 1960s allowed less than one pregnancy when taken by 100 women for at least a year, the FDA said. But in the last decade, the government has approved pills allowing more than two pregnancies for every 100 woman-years of use.
The FDA is asking the 14 members of its reproductive drugs panel whether that difference in performance is large enough for concern.
Government scientists are in disagreement over whether there should be a strict limit on the failure rate a drug can have and still be approved, the AP reports.
At the meeting, panelists said the FDA should work with the industry to find better ways to include a wider range of women in studies without making it too burdensome for manufacturers.
Still, panelist and Maryland physician Bruce Stadel said it was imperative for companies to "test what they propose to market in the people they're proposing to market to."
Likewise, they called on drugmakers to compare new products against other widely-used, recently-approved contraceptives, rather than against use of no contraceptive at all.
Also at issue is the rising pregnancy rate among contraceptives studied in the last decade.
FDA officials have said they have seen higher pregnancy rates in recent trials, but it is unclear whether that is due to lower hormone doses, improper use, or other factors.
Birth control pills approved from 1960 to 1970 saw less than one pregnancy for every 100 women who took them for a year. In the past 10 years, however, some were approved with rates above two per 100 women.
FDA staff have been divided over whether to limit acceptable pregnancy rates with new products. Even so, "the newer generation products are highly effective in preventing pregnancy," the agency said in its statement.
Panelists said estimating the risk per 100 women, although widely used, was a "crude" way to establish pregnancy risk and manufacturers should move toward a more comprehensive method, Reuters reports.
Prepared by Alexander Timoshik
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