Among other things, users must remain upright for at least 30 minutes after taking their morning pill. Gastrointestinal problems, some of them serious, have been reported. In a clinical trial, 12. 9 percent of 1,545 women taking the drug broke a bone, compared with 16.2 percent of 1,521 women who took a placebo. In a clinical trial, 16.3 percent of 678 women who took a placebo had a vertebral fracture within three years, compared with 11.3 percent of 698 Actonel users. But unlike estrogen, it does not increase cancer risk.
Studies are under way to determine if it reduces breast-cancer risk.
In a clinical trial, 4.3 percent of 1,457 women who took placebo suffered vertebral fracture, compared with 1.9 percent of 1,401 who took the drug. Calcitonin, a hormone produced by thyroid cells, is available as a nasal spray or by injection. Works by blocking cells that cause bone loss. Drug may ease back pain caused by vertebral fractures. Nausea, nasal irritation, but fewer side effects than other medications.