Medroxyprogesterone acetate suspension injection (Depo- Provera) is a long-acting progestogen only contraceptive that is administered intramuscularly, every 12 weeks. Pfizer Canada1 is informing health-care professionals that results of new clinical studies suggest that:
• Women who use medroxyprogesterone acetate suspension for injection (Depo-Provera) may suffer substantial loss in bone mineral density.
• The loss in bone density is greater with increasing duration of treatment.
• The loss in bone density may not be completely reversible.
• It is unknown whether the use of medroxyprogesterone injection (Depo-Provera) during adolescence or early adulthood, a critical period of bone accretion, will reduce peak bone mass and increase the risk of osteoporotic fracture in later life.
The product label under the sections of Indications and Clinical Use, Warnings, Dosage and Administration and Adverse Reactions will be appropriately updated to reflect the above findings.
The Chairman of the UK Committee on Safety of Medicines (CSM) has also written to health-care professionals about these recent findings from the clinical studies and the implications therein, while reminding health professionals that the effect of medroxyprogesterone acetate injection (Depo-Provera) on bone mineral density has been recognized for many years. In addition, the CSM also advises that:
• In adolescents, medroxyprogesterone injection (Depo-Provera) may be used as first-line contraception only after other methods have been discussed with the patient and considered to be suitable or unacceptable.
• In women of all ages, careful re-evaluation of the risks and benefits of treatment should be carried out in those who wish to continue use for more than two years.
• In women with significant lifestyle and/or medical risk factors for osteoporosis, other methods of contraception should be considered.
1. 'Dear Health-care Professional' letter, 18 November 2004. Available on the Internet at www.hc-sc.gc.ca
2. Letter from the Chairman, UK Committee on Safety of Medicines, 18 November 2004. Available on the Internet at www.mhra.gov.uk