Is QT interval prolongation harmful? A regulatory perspective.

Drugs that prolong the QT interval may increase the risk of torsades de pointes, a potentially lethal ventricular arrhythmia. In recent years, spontaneous reports have highlighted these complications in patients receiving certain antihistamines (e.g.

Development and approval of vaccines in the United States.

In the United States, vaccines and the establishments in which they are manufactured are required to be licensed by the Food and Drug Administration (FDA) before the vaccine can be marketed. This licensing process, as well as the development and investigation of vaccines, is regulated by the FDA's Office of Biologics Research and Review. An application for licensing must contain information supporting the safety, effectiveness, purity and potency of the product.

Evidence used for approval of new drugs.

New drugs in the United States are studied under investigational new drug exemptions. Commercial sponsors then gather the accrued data into a new drug application to support safety and effectiveness for marketing. The Food, Drug and Cosmetic Act of 1938, as amended in 1962, requires that effectiveness of a drug for its intended use be demonstrated by substantial evidence, consisting of adequate and well-controlled investigations, including clinical investigations, by experts qualified by training and experience to evaluate the drug.