Bayer defends Yasmin against BMJ studies
Bayer has rallied strongly behind its top-selling contraceptive brand Yasmin after two studies in the British Medical Journal questioned the drug’s safety.
Both pieces of research suggested an increased risk of blood clots for women using an oral contraceptive containing drospirenone – a progestogen used in Yasmin – rather than other contraceptive pills.
The researchers conceded that the risk was low, but this has not stopped Bayer excoriating the research: “The manner in which the authors applied the study methodology reported in these two publications show significant flaws,” the company said.
The first, a case-control study based on US claims data by Susan S. Jick et al, found the risk of non-fatal venous thromboembolism (VTE) among users of contraceptive pills containing drospirenone was twice that of those containing levonorgestrel.
The second study, this time using information from the UK General Practice Research Database and by Lianne Parkin et al, found a threefold increased risk of a first non-fatal VTE.
The manufacturer’s robust defence of its product has centred on the weight of previously available data for the use of the drug.
“The databases used provide less reliable conclusions than are available from existing scientific evidence around the risk of developing VTE, or blood clots, with combination oral contraceptives (COCs),” Bayer said.
Ilka Schellschmidt, the company’s head of global medical affairs, women’s healthcare, pointed to more than 15 years’ clinical data and up to 10 years of post-marketing safety study results.
These “support Bayer’s assessment that its drospirenone-containing COCs are safe and effective when used as indicated and that the risk of VTE is similar to any other low-dose estrogen COC studied, regardless of the progestogen”, Schellschmidt insisted.
All contraceptive pills are associated with increased risk of blood clots, as well as breast cancer and hypertension – however, they are also thought to lower the risk of ovarian and endometrial cancer.