Since the 1990s, when numerous non-cardiac drugs were first recognized to have the potential to prolong the QT interval and cause torsades de pointes (TdP), clinicians, drug regulators, drug developers, and clinical investigators have become aware of the complexities of assessing evidence and determining TdP causality for the many drugs being marketed or under development. To facilitate better understanding, the Arizona Center for Education and Research on Therapeutics, known as AZCERT, has developed the CredibleMeds.org website which includes QTdrugs, a listing of over 220 drugs placed in four risk categories based on their association with QT prolongation and TdP. Since the site was launched in 1999, it has become the single and most reliable source of information of its kind for patients, healthcare providers, and research scientists. Over 96,000 registered users rely on the QTdrugs database as their primary resource to inform their medication use, their prescribing or their clinical research into the impact of QT-prolonging drugs and drug-induced arrhythmias. The QTdrugs lists are increasingly used as the basis for clinical decision support systems in healthcare and for metrics of prescribing quality by healthcare insurers. A free smartphone app and an application program interface enable rapid and mobile access to the lists. Also, the CredibleMeds website offers numerous educational resources for patients, educators and healthcare providers that foster the safe use of medications.
