Managing drug-induced QT prolongation in clinical practice. Issue 1149 (29th October 2020)

• Record Type: Journal Article
• Authors: Khatib, Rani; Sabir, Fatima R N; Omari, Caroline; Pepper, Chris; Tayebjee, Muzahir Hassan
• Is Part Of: Postgraduate medical journal. Volume 97:Issue 1149(2021)
• Page Start: 452
• Page End: 458
• Publication Date: 2020-10-29
• Subjects: Cardiology -- Pacing & electrophysiology -- Clinical pharmacology -- Therapeutics -- Adverse events; Medicine -- Periodicals; 610
• DOI: 10.1136/postgradmedj-2020-138661
• Languages: English
• ISSNs: 0032-5473

Abstract

ABSTRACT: Many drug therapies are associated with prolongation of the QT interval. This may increase the risk of Torsades de Pointes (TdP), a potentially life-threatening cardiac arrhythmia. As the QT interval varies with a change in heart rate, various formulae can adjust for this, producing a 'corrected QT' (QTc) value. Normal QTc intervals are typically <450 ms for men and <460 ms for women. For every 10 ms increase, there is a ~5% increase in the risk of arrhythmic events. When prescribing drugs associated with QT prolongation, three key factors should be considered: patient-related risk factors (eg, female sex, age >65 years, uncorrected electrolyte disturbances); the potential risk and degree of QT prolongation associated with the proposed drug; and co-prescribed medicines that could increase the risk of QT prolongation. To support clinicians, who are likely to prescribe such medicines in their daily practice, we developed a simple algorithm to help guide clinical management in patients who are at risk of QT prolongation/TdP, those exposed to QT-prolonging medication or have QT prolongation.