Why are some bisphosphonates approved for cancer treatment, others for osteoporosis treatment and some for both?
Health Canada approvals for medications depend on the trials which have been performed. Some bisphosphonates have clinical trials showing effectiveness for osteoporosis, some for cancer and some for both. Only intravenous bisphosphonate has proven effectiveness for the prevention and treatment of cancer that has spread to bone. Bisphosphonate for bone cancer is given intravenously every 2 to 4 weeks; the same medications for osteoporosis can be given at intervals as long as every 1 to 2 years. Bisphosphonates are also effective in preventing the bone loss associated with some cancer chemotherapy. Bisphosphonate side effects are different in patients treated for cancer than for patients treated for osteoporosis. This is due to the higher bisphosphonate dosage in cancer patients as well as the other cancer treatments given at the same time, such as chemotherapy and radiotherapy.
