Background: QTc prolongation can trigger potentially lethal arrhythmias. Almost all azole antifungals, which are used in vulnerable patients, prolong the QTc interval and thus, may increase arrhythmia risk. The Tisdale-risk-score allows to identify patients at risk for drug-induced QTc prolongation but has not yet been investigated in this patient population.
Objective: To evaluate the sensitivity and specificity of the Tisdale-score with regard to detected QTc prolongations in patients prescribed systemic azole antifungals.
Methods: For six months (12/23-05/24), prescriptions of systemic azole antifungals were retrospectively recorded in adult inpatients of all medical specialties of a university hospital. Risk factors for QTc prolongation, including concomitant drugs and ECGs, were documented and the Tisdale-score and its sensitivity and specificity were calculated.
Results: In the study period, 319 systemic azole prescriptions (cases) were recorded for 259 patients. The median age of all cases was 61 years, 45% (143) were female. Including the systemic azole, a prescription of ≥2 QT-drugs was present in 283 (89%) cases. The median Tisdale-score was 7 (moderate risk). ECGs after azole initiation were available in 149 cases. Out of these, relevant QTc prolongations occurred in 7 cases (4.7%). Sensitivity of the Tisdale-score was 100%, specificity 30%.
Conclusion: Patients prescribed systemic azole antifungals are at risk of QTc prolongation due to regular use of multiple QT-drugs. However, relevant QTc prolongations were rare in the patient population studied. The Tisdale-score achieved a good sensitivity for the identification of patients at risk for QTc prolongation.
Keywords: antifungal agents; critical care; long QT syndrome; pharmaceutical care; risk assessment.
© 2026 Steinbrech, Amann, Irlbeck, Clauß and Strobach.