Review Possible Deletion of Medroxyprogesterone from the 14th Who Model List of Essential Medicines

Background In 2004, WHO Pharmaceuticals Newsletter reported a Pfizer Canada advice originated by results of new clinical studies that suggest the association between use of medroxyprogesterone acetate suspension for injection and substantial loss in bone mineral density. The publication stressed: “The loss in bone density is greater with increasing duration of treatment. The loss in bone density may not be completely reversible. 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”. Long-term use of the injectable contraceptive depot medroxyprogesterone acetate (DMPA) is associated with a reduction in bone mineral density (BMD), particularly in the lumbar spine. The cause of DMPA-associated bone loss is not known, but the relative estrogen deficiency induced by DMPA use could be responsible. Actually, in the 13 WHO Model List of Essential Medicines (section 18.7 Progestogens) a medroxyprogesterone acetate tablet was included. It seems that oral use of MPA (commonly associated to estrogens) could have a different consequence in bone metabolism.