First 'extended-regimen'OC approved.

Seasonale, the world's first extended-regimen oral contraceptive (OC), designed to reduce the number of times a woman menstruates each year, has been approved by the U.S. Food and Drug Administration.

Like many low-dose OCs, Seasonale contains 150 [micro]g of the progestin levonorgestrel and 30 [micro]g of the estrogen ethinyl estradiol. But Seasonale is packaged as a 91-day regimen, rather than the 28-day regimen of most conventional OCs. With Seasonale, women take one active pill daily for 84 days (12 weeks) and then one placebo pill daily for seven days. This induces withdrawal bleeding only four times a year. In contrast, women who take most conventional OCs take one active pill daily for 21 days (three weeks), then one placebo pill daily for seven days. This induces withdrawal bleeding 13 times each year.

A one-year, multicenter, randomized trial from the United States, reported in the August 2003 issue of the journal Contraception, confirmed that Seasonale effectively prevents pregnancy and has a safety profile similar to that of comparable conventional OCs. Women who took Seasonale did report more breakthrough bleeding during the first few months of use than did women taking conventional OCs, but the new regimen was still well tolerated.

Possible but unproven benefits of extended-regimen OCs are greater protection against anemia than that provided by conventional OCs; increased effectiveness during typical use because of fewer pill-free intervals; and improved compliance for women who have difficulty returning to clinics or pharmacies for more pill packets. "A four-month supply of pills is built into the extended regimen, so the all-too-common practice of providing clients with only one cycle of pills at a time can be avoided," notes Dr. James D. Shelton, senior medical scientist at the U.S. Agency for International Development.

Because menstrual suppression reduces overall menstrual bleeding and associated pain and cramping, many health care providers already prescribe continuous OC use for women with severe menstrual problems. But because the long-term effects of menstrual suppression and of slightly higher levels of hormonal exposure are unknown, some researchers and providers are reluctant to recommend extended-regimen OCs to women with normal menstrual cycles. "Hopefully, over time, good evidence will emerge on all of these issues," Dr. Shelton says.