Correction: Paget disease of bone

In the article “Paget disease of bone: Diagnosis and drug therapy” in the July 2013 issue, an error occurred on page 458, under the subheading “Intravenous bisphosphonates.” The text read, “Pamidronate was approved in 1994. Although it does not contain nitrogen, it is quite effective in many patients with Paget disease.” Pamidronate in fact does contain nitrogen.