Inhibition of repolarizing ionic currents by drugs

Every pharmacological substance that prolongs cardiac repolarization produces a risk of serious ventricular arrhythmias leading eventually to sudden death. Numerous non-cardiovascular drugs already in the market have been associated with altered cardiac repolarization and pro-arrhythmic effects. Because this side effect is serious (albeit infrequent), every new chemical entity intended for human use should be screened during the preclinical stages of its pharmaceutical development. Various in vitro and in vivo models have been established to accomplish this screen. Standard procedures are now available to prevent that drugs non-intentionally affecting cardiac repolarization will be developed and launched in the future.