WASHINGTON -- The government cleared the way yesterday for sales of the first birth control pill to eliminate monthly menstrual periods for as long as women use it.
Women who go on Lybrel, as the new birth control is called, will take a pill every day, without any of the brief breaks that mark use of the other oral contraceptives now available.
Some of those other birth control pills shorten bleeding or limit periods to as infrequently as every three months, but polls indicate that close to half of women surveyed would prefer to not menstruate at all.
Dr. Michelle C. Fox, director of the Family Planning Program at the University of Maryland Medical Center, said it would be especially appealing to women who experience severe pain during their periods.
"I don't think it's for everyone," Fox said. "But for those women who either for convenience or health reasons don't want to get their menstrual cycle, this is a great option."
The pill's maker, Wyeth Pharmaceuticals of Madison, N.J., expects to begin sales of the 28-day pill packs in July. A spokeswoman said the price has not been set.
Cost might discourage some use, especially if the drug's price is far more than some generic forms of birth control. Analysts have predicted as much as $250 million in yearly sales. Last year, women spent more than $3 billion on oral contraceptives, said IMS Health, a health care information firm.
Lybrel will work the same way as other oral contraceptives, lowering a woman's production of the hormones that prepare her body for pregnancy. The pill is made from low doses of three common contraceptive ingredients.
In approving the drug, the Food and Drug Administration found Lybrel safe. Yet like other oral contraceptives, Lybrel heightens the risk for blood clots, heart attack and stroke, especially among cigarette smokers. It is also likely to cause unpredictable bleeding or spotting, particularly during the initial months of use.
Studies showed that 41 percent of women still taking the pill after a year experienced bleeding or spotting. Those two studies - of 2,400 women ages 18 to 49 - lasted a year, prompting critics to express concern that there weren't enough data about the long-term effects to give interested women an informed choice.
Paula Derry, a Baltimore psychologist who has studied how women decide to suppress their menstrual cycles, worried that Lybrel users might not appreciate the unknowns surrounding its impact on more than just their reproductive systems.
"There are less extreme ways for addressing, say, severe menstrual cramps than taking a product that suppresses a woman's entire reproductive system," said Christine Hitchcock, who researches menstruation and ovulation at the University of British Columbia.
Dr. Daniel Shames, of the FDA's drug evaluation offices, said Wyeth will conduct a study of Lybrel's long-term effects, but indications were that its impact was no different than other oral contraceptives.