Drug-induced QT prolongation

The Cardiac Risk of Chloroquine in Unapproved Indications

Friday, March 27, 2020 - 1:57am

Recently, the unapproved use of the antimalarial drug, chloroquine, has been touted as a treatment for COVID-19 with some reported deaths with its use in afflicted patients.

Key Points: 
  • Recently, the unapproved use of the antimalarial drug, chloroquine, has been touted as a treatment for COVID-19 with some reported deaths with its use in afflicted patients.
  • Because the QT interval is influenced by heart rate, it is most often given as the corrected QT interval or QTc.
  • Even therapeutic doses of chloroquine in healthy patients are associated with prolongation of QTc1, although this is generally well tolerated.
  • This is why chloroquine has specific warnings in its labeling to inform of the potential danger in patients with underlying risk factors (cardiac disease, hypokalemia, hypomagnesemia, bradycardia)3.