Drugs that cause Torsades de pointes and increase the risk of sudden cardiac death.
Torsades de pointes (TdP) is a potentially life-threatening arrhythmia associated with not only antiarrhythmic drugs, but noncardiac drugs of many different classes. All these drugs prolong the QT interval by their blocking of the potassium channel I(Kr), and many are metabolized by the cytochrome P450 isoenzyme CYP3A4. Polypharmacy with other drugs utilizing the same enzyme, or inhibiting CYP3A4, can lead to TdP. A consistent finding of all the QT-prolonging drugs is predominance of TdP in women. Other risk factors for QT prolongation and TdP include hypokalemia, congestive heart failure, and structural heart disease. Knowledge of potential drug interactions and other risk factors for TdP can help in reducing the number of adverse events associated with the use of QT-prolonging drugs.
Milton S. Hershey Medical Center, Division of Cardiology, 500 University Drive/H047, Hershey, PA 17033, USA. dwolbrette@psu.edu
Deborah L
DL
Wolbrette
D000889:Anti-Arrhythmia Agents / Q000009:adverse effects; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D014150:Antipsychotic Agents / Q000009:adverse effects; D065607:Cytochrome P-450 Enzyme Inhibitors; D016757:Death, Sudden, Cardiac / Q000209:etiology*; D004347:Drug Interactions; D004562:Electrocardiography; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced* / Q000150:complications; D015221:Potassium Channels / Q000187:drug effects*; D012307:Risk Factors; D016171:Torsades de Pointes / Q000139:chemically induced* / Q000150:complications
D000889:Anti-Arrhythmia Agents; D000900:Anti-Bacterial Agents; D014150:Antipsychotic Agents; D065607:Cytochrome P-450 Enzyme Inhibitors; D015221:Potassium Channels