In a recent case-control analysis published in British Journal of Medicine, women who use oral contraceptives containing the newer progesterone Drospirenone are at a higher risk for venous thromboembolism (VTE) than those using contraceptives containing Levonorgestrel.
Study author Dr. Lianne Parkin and colleagues from the Dunedin School of Medicine, University of Otago, New Zealand, and analyzed women aged 15 to 44 years without major risk factors for venous thromboembolism, who started using an oral contraceptive pill containing oestrogen 30 microgm plus either levonorgestrel or drospirenone between May 2002 and September 2009.
AdvertisementIt was observed that the use of drospirenone contraceptive was associated with a three fold higher risk of non-fatal idiopathic venous thromboembolism (VTE) as compared to levonorgestrel use. The odds ratio, adjusted for body mass index, was 3.3. Sub analyses further suggested that referral, first time user, diagnostic, duration of use, and switching biases were unlikely explanations for this finding.
Dr. Parkin commented saying, "These findings support more recent studies that suggest that drospirenone oral contraceptives are not as safe as levonorgestrel oral contraceptives with respect to venous thromboembolism and, in the absence of other considerations, should not be the first choice in oral contraception."
She concluded by saying that their findings "Add to emerging evidence that use of the oral contraceptive containing drospirenone is associated with a higher risk of VTE than are preparations containing levonorgestrel."