Drug-Induced QTc Interval Prolongation: A Multicenter Study to Detect Drugs and Clinical Factors Involved in Every...

Area of Science:

• Cardiology
• Clinical Pharmacology

Background:

• The prevalence of drug-induced QT prolongation in real-world clinical settings remains largely unknown.
• Understanding associated patient factors and specific drugs is crucial for risk management.

Purpose of the Study:

• To determine the occurrence and characteristics of drug-induced QT prolongation in common clinical practices.
• To analyze a subgroup of patients treated with dextropropoxyphene for regulatory interest.

Main Methods:

• 1270 patients undergoing drug administration had medical history, comorbidities, and ECGs (baseline, intra-, post-treatment) recorded.
• QT interval was corrected using Bazett's formula.
• Analysis included univariate and multivariate assessments of drug-associated QTc prolongation.

Main Results:

• 9.9% of patients had QTc >450/470 ms, and 3% had QTc >500 ms.
• Significant QTc prolongation was linked to congestive heart failure, ischemic heart disease, diabetes, renal failure, arrhythmias, hypothyroidism, and bradycardia.
• Drugs associated with QTc prolongation included clarithromycin, haloperidol, tramadol, amiodarone, glyceryl trinitrate, and various beta-lactamase inhibitor combinations; furosemide, clarithromycin, glyceryl trinitrate, and beta-lactamase inhibitors remained significant after multivariate analysis.

Conclusions:

• QT interval prolongation is frequent in clinical practice.
• Identification of associated clinical factors and drugs is key for developing monitoring and prevention strategies.