Table 6.

Methods of reducing the risk of drug-induced torsades de pointes

• Where possible, avoid use of QTc interval–prolonging drugs in patients known to have pretreatment QTc intervals >450 ms. • Discontinue QTc interval–prolonging drug(s) if QTc interval prolongs to >500 ms. • Reduce dose or discontinue QTc interval–prolonging drug(s) if the QTc interval increases ≥60 ms from pretreatment value. • Maintain serum potassium concentration within normal range. • Maintain serum magnesium concentration within normal range. • Maintain serum calcium concentration within normal range. • Where possible, avoid the use of QTc interval–prolonging drugs in patients with heart failure and a left ventricular ejection fraction <20%. • Avoid important drug interactions (Table 4). • Adjust doses of renally eliminated QTc interval–prolonging drugs in patients with acute kidney injury or chronic kidney disease (Table 5). • Avoid rapid intravenous administration of QTc interval–prolonging drugs. • Where possible, avoid concomitant administration of >1 QTc interval–prolonging drug. • Avoid use of QTc interval–prolonging drugs in patients with a history of drug-induced torsades de pointes or those who have previously been bresuscitated from an episode of sudden cardiac death. • Avoid use of QTc interval–prolonging drugs in patients who have been diagnosed with one of the congenital long QT syndromes.