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Search for Drugs that Prolong QT & induce Torsades de Pointes (TdP)

Based on ongoing systematic analysis of all available evidence, CredibleMeds® places drugs into broad categories based on whether each can cause QT prolongation or TdP.  These actions are highly dependent on the circumstances of each drug’s use AND each patient’s clinical characteristics.

QT/TdP Risk Categories for Drugs


Known Risk of TdP - These drugs prolong the QT interval AND are clearly associated with a known risk of TdP, even when taken as recommended.
Possible Risk of TdP - These drugs can cause QT prolongation BUT currently lack evidence for a risk of TdP when taken as recommended.
Conditional Risk of TdP - These drugs are associated with TdP BUT only under certain conditions of their use (e.g. excessive dose, in patients with conditions such as hypokalemia, or when taken with interacting drugs) OR by creating conditions that facilitate or induce TdP (e.g. by inhibiting metabolism of a QT-prolonging drug or by causing an electrolyte disturbance that induces TdP).
Drugs to Avoid in Congenital Long QT Syndrome (cLQTS) - These drugs pose a high risk of TdP for patients with cLQTS and include all those in the above three categories (KR, PR & CR) PLUS additional drugs that do not prolong the QT interval per se but which have a Special Risk (SR) because of their other actions.