The Drug Safety Update is an NHS Evidence accredited provider
16 June 2011
The June 2011 edition of Drug Safety Update considers both the risk of femoral fractures with bisphosphonates and the risk of venous thromboembolism (VTE) with the oral contraceptive Yasmin. Recent study data are reviewed and updated safety advice is provided.
Healthcare professionals should follow the advice given in the Drug Safety Update, they key messages of which are given below.
Bisphosphonates: atypical femoral fractures
As discussed in MeReC Rapid Review No. 3896, a Europe-wide review of bisphosphonates and their association with atypical femoral fractures has been published. The Drug Safety Update gives updated advice to healthcare professionals around the management of patients taking bisphosphonates who develop atypical femoral fractures. Key messages are:
- Atypical femoral fractures are often bilateral; therefore the contralateral femur should be examined in bisphosphonate-treated patients who have sustained a femoral shaft fracture
- Discontinuation of bisphosphonate therapy in patients suspected to have an atypical femur fracture should be considered while they are evaluated, and should be based on an assessment of the benefits and risks of treatment for the individual
- During bisphosphonate treatment, patients should be advised to report any thigh, hip, or groin pain. Any patient who presents with such symptoms should be evaluated for an incomplete femur fracture
- The optimum duration of bisphosphonate treatment for osteoporosis has not been established. The need for continued treatment should be re-evaluated periodically based on the benefits and potential risks of bisphosphonate therapy for individual patients, particularly after five or more years of use
Yasmin: risk of venous thromboembolism
As discussed in MeReC Rapid Review No 3549, epidemiological studies have found an increased relative risk of VTE associated with the use of drospirenone-containing combined oral contraceptives (COCs), e.g. Yasmin, compared with levonorgestrel-containing COCs. The key messages in the Drug Safety Update are:
- The risk of VTE in association with drospirenone-containing pills, including Yasmin, is higher than that for levonorgestrel-containing ‘second generation’ pills and may be similar to the risk for ‘third-generation’ pills that contain desogestrel or gestodene
- Levonorgestrel-containing pills have the lowest thrombotic risk and are the safest pill for a woman who wants to start or switch contraception. Prescribers should be aware of the updated information when discussing the most suitable type of contraceptive for a woman who wants to start or switch contraception
- Any prescribing decision should take into account each woman’s personal risk factors and any contraindications, including her experience with other contraceptive formulations
- All combined oral contraceptives (COCs), including Yasmin, should be prescribed with caution to obese women (BMI >30), or those with a higher baseline risk of VTE for other reasons
- Estimates are not precise, but for women who do not use a contraceptive pill about one case of VTE per 10,000 is expected each year. By comparison, about six cases of VTE are expected to occur in every 10,000 pregnancies. In healthy women who take Yasmin, between three and four cases of VTE are expected to occur in every 10,000 women each year. The previous estimate was between two and four cases in every 10,000 women each year. All these estimates relate to women who are otherwise in good health.
- There is no reason for women to stop taking drospirenone-containing COCs or any other COC on the basis of these findings
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