Class I
If the QT-interval or QTc reaches a length .500 ms or increases by .60 ms compared with baseline, treatment with the particular drug should be ceased or dose reduced (Level of Evidence: C)
Hypokalaemia should be avoided during treatment with drugs capable of prolonging the QT interval (level of evidence: C)
Concomitant treatment with more than one drug with the propensity of prolonging the QT interval should be avoided if possible (level of evidence: C)
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Class IIa
Before initiation of treatment, assessment of cardiac risk is needed (level of evidence: C)
The QT interval should be evaluated before initiation of treatment and during titration of dose (level of evidence: C)
In elderly, treatment should be done with caution (level of evidence: C)
If cardiac risks are identified, the cardiac risk factors should be optimized and/or a drug with a more favourable risk profile should be preferred if possible in the clinical situation (level of evidence: C)
In case of structural heart disease, QT prolongation or cardiac symptoms referral to a cardiologist should be considered (level of evidence: C)