For the past few years, most physicians have routinely treated osteoporosis in the same manner. The most commonly used medication class is the bisphosphonates (Fosamax, Actonel, Boniva and Reclast). The reason for this is quite obvious. The increases in bone mineral density, the decrease in fracture risk, the tolerability, and the route of administration all are superior for this drug class compared to the other drug classes on the market. However, new data and an additional FDA approval may make some physicians rethink this and make changes in their treatment of osteoporosis.
Evista is commonly referred to as a selective estrogen receptor modulator (SERM). SERMs may act by blocking estrogen receptors in the breast. In recent data from the STAR (Study of Tamoxifen and Raloxifene) trial, which included nearly 20,000 postmenopausal women at increased risk of breast cancer, the osteoporosis drug Evista (raloxifene) equaled an established breast cancer drug, tamoxifen, at preventing breast cancer in postmenopausal women. This is important because in previous studies tamoxifen was shown to reduce breast cancer risk by 50%. Evista also appeared to carry fewer side effects with lower rates of uterine cancer, clotting problems and cataracts then the established frequently used drug tamoxifen.
The one major difficulty found with the results was in regards to noninvasive breast cancer. In this group, the Evista participants had a higher rate of breast cancer. This difference is being downplayed by the researchers, as these cancers, lobular carcinoma in situ (LCIS) or ductal carcinoma in situ (DCIS), are not serious forms of breast cancer and are not considered life threatening disease.
FDA Approval for Evista
In September 2007, the FDA approved Evista for reducing the risk of invasive breast cancer in postmenopausal women with osteoporosis and in postmenopausal women at high risk for invasive breast cancer. Evista is only the second drug approved to reduce the risk of breast cancer.
As mentioned previously, this drug has not been considered a first line agent by most practitioners for osteoporosis. This has been due to weaker fracture and bone mineral density changes. One of the major criticisms of Evista is the lack of adequate fracture data of the hip region. However, hip fracture risk in females often does not become significant until their mid 60's. In light of the STAR data, we may consider placing younger postmenopausal females on this medication to protect their risk of vertebral fracture and invasive breast cancer.
As with most drugs, Evista has some potential serious side effects. These are rare, but include blood clots in the legs and lungs, and death due to stroke. Women with current or prior blood clots in the legs, lungs, or eyes should not take Evista.
Other potential side effects include hot flashes, leg cramps, swelling of the legs and feet, flu-like symptoms, joint pain, and sweating. Evista should not be taken by premenopausal women and women who are or may become pregnant because it may cause harm to the unborn baby. In addition, Evista should not be taken with cholestyramine (a drug used to lower cholesterol levels) or estrogens.