Continuous dose contraceptive launched in US
Wyeth's Lybrel, the first ever contraceptive pill designed to be taken by women 365 days a year, has been launched in the US.
Existing contraceptive pills are designed to be taken for 21 days, followed by a week-long, pill-free interval in which the woman has period-like bleedings, partly intended to reassure her she is not pregnant.
Contrary to popular belief, women do not ovulate during the pill-free interval, but merely experience a withdrawal from the hormones which resembles menstruation.
Market research has convinced manufacturers Wyeth that there is demand for a pill which can be taken without the need for the pill-free interval, freeing the patient of inconvenient breakthrough bleeding and other period-like symptoms.
But not all women taking Lybrel experience complete freedom from bleeding. About half of the women enrolled on one trial of the drug dropped out of the study because of the irregular and unpredictable bleeding and spotting that can replace the pill-free interval.
Wyeth may also have an uphill battle in convincing some women that doing away with the period-like symptoms is not unnatural or dangerous, despite extensive studies proving its safety. Women who experience particularly painful or inconvenient symptoms, however, are thought to be the most likely to take the new product.
"As a leader in women's healthcare, Wyeth is proud to be the first to provide women with a contraceptive option that allows many of them to put their monthly cycle on hold," said Ginger Constantine, Vice President, Women's Health Care, Wyeth Pharmaceuticals.
Lybrel is a low-dose version of the traditional contraceptive pill, containing 90 micrograms levonorgestrel and 20 micrograms ethinyl estradiol.
FDA demands for improvements in the manufacturing process for the drug has held up its approval for some time, Wyeth first filing it with regulators in 2005.