The FDA has approved a new oral contraceptive (Seasonale®, Barr Laboratories) for women. Seasonale® contains a progestin (levonorgestrel) and an estrogen (ethinyl estradiol), which are active ingredients in traditional oral contraceptives.

Seasonale® offers a 91-day regimen. Tablets containing the active hormones are taken for 12 weeks (84 days), followed by one week (seven days) of placebo (inactive) tablets. Conventional oral contraceptive use is based on a 28-day regimen (21 days of active tablets, followed by seven days of placebo tablets).

Under the new dosing regimen, the number of expected menstrual periods usually experienced by women is reduced from once a month to about once every three months. As with the conventional 28-day regimen, women have a menstrual period while taking the placebo tablets.

Although Seasonale® users have fewer scheduled menstrual cycles, many women, especially in the first few cycles of use, had more unplanned bleeding and spotting between the expected menstrual periods than women taking a conventional 28-day cycle oral contraceptive.

Some physicians have raised concerns about the consequences of long-term suppression of menstruation, suggesting that data are insufficient to prove that suppression is safe. They also noted that the women in the studies were already taking oral contraceptives and thus would “automatically” be able to tolerate the medication; they were not compared with a control group of women who were not taking oral contraceptives. The supporters of menstrual suppression argue that ovulation itself can inflame the lining of the ovary and might be linked to ovarian cancer. The debate, no doubt, will rage on.

Because Seasonale® users can expect to have fewer periods, the label also advises women to consider the possibility that they might be pregnant if they miss any scheduled periods.

The FDA has approved the NDA for Seasonique (canadian levonorgestrel/ethinyl estradiol 0.15 mg/0.03 mg and ethinyl estradiol 0.01 mg) tablets (Barr Phar-maceuticals/Duramed) to prevent pregnancy. Seasonale, Barr’s earlier extended-cycle oral contraceptive, was launched in 2003 as a 91-day regimen. Tablets containing the active hormones are taken for 12 weeks (84 days), followed by seven days of placebo (inactive) tablets, thus offering the convenience of just four menstrual periods per year.

Seasonique provides continuous hormonal support in the form of a low dose of estrogen in place of seven placebo tablets taken during the month. Patients take the active tablets for 84 consecutive days, followed by seven days of 0.01 mg of ethinyl estradiol. The regimen is also designed to reduce the number of withdrawal bleeding periods to four times per year.

Barr received an approvable letter for Seasonique in August 2005. In March 2006, the FDA determined that no additional clinical studies would be required to support the approval.

Wyeth’s Lybrel, the first continuous-use oral contraceptive, has been approved. The tablet comes in a 28-day pack with low-dose combination tablets containing 90 mcg of a progestin (generic levo­norgestrel) and 20 mcg of an estrogen (ethinyl estradiol).

With the traditional contraceptives, patients take the medication for 21 days, then stop for seven days; the placebo or pill-free time intervals last four to seven days to simulate a menstrual cycle. The Lybrel regimen does not include the week off from the placebo tablets.

Women who use Lybrel do not have a scheduled menstrual period but may experience unplanned breakthrough bleeding or spotting; this effect usually tapers off within the first year of use.

The safety and efficacy of Lybrel as a contraceptive method were supported by two one-year clinical studies enrolling more than 2,400 women 18 to 49 years of age.