Pulmonary embolisms are blockages in one of the arteries leading to the lungs formed by a substance that has migrated through the bloodstream from another part of the body, commonly the legs. Clinical studies of Yaz conducted in Denmark and the Netherlands suggest a link between the Yaz ingredient drosperinone and a higher occurrence of blood clots than in women who took traditional contraceptives containing levonorgestrel.

A spokesperson for Bayer said that the company is cooperating with the investigation, but that it stood by the safety of its drug.

“A singular case, as tragic and sad as it is, does not indicate an increased risk for the whole group of women who take the pill,” Oliver Renner, a Bayer spokesman, told Bloomberg. “Studies have shown that the risk isn’t higher for Yaz than for other oral contraceptives.”

Of course, Bayer’s spokesperson dismisses the results of the two independent clinical trials and focuses on the more favorable outcome the Bayer-funded clinical test, which suggested the risks of Yaz were similar to those of traditional birth control therapies.

As the top selling oral contraceptive in the world, Yaz is big business for Bayer. The drug brought in $1.86 billion just in the first quarter of 2009.

SOURCE: Yaz Lawsuit › Switzerland investigates the death of young Yaz user