The Medicines and Healthcare products Regulatory Agency (MHRA) has published Drug Safety Update for April 2010 (PDF).
This issue contains drug safety advice regarding the risk of venous thromboembolism (VTE) with Yasmin® covers the recently updated EMA regarding the interaction between clopidogrel and omeprazole or esomeprazole.
This update notes that the risk of VTE expected with Yasmin® was expected to be similar to that seen with levonorgestrel containing, or second generation, contraceptive pills. This was confirmed in two prospective cohort studies. However, two more recent studies, one a Danish cohort study and one a Dutch case-control study, have indicated that the risk may be higher than previously thought. The relative risk of VTE was quoted as 1.64 (95% CI 1.27-2.10) and 1.7 (95% CI 0.7-3.9) respectively which would place the risk between second and third generation combined oral contraceptives but still below the risk associated with pregnancy.
Some methodological flaws are present in both of these more recent studies and as such no firm conclusions can be made at this time. Clinicians are advised to discuss this new information with patients before prescribing or at the next routine review. Patients are advised to continue taking this medication but seek advice if they are worried.
Action: Clinicians will find this publication to be a useful review of current issues in drug safety.