title: Safety information on QT-interval prolongation: comparison of European Union and United States drug labeling.
abstract: Prolongation of the QT interval can predispose to fatal ventricular arrhythmias. Differences in QT-labeling language can result in miscommunication and suboptimal risk mitigation. We systematically compared the phraseology used to communicate on QT-prolonging properties of 144 drugs newly approved (1st January 2006 to 1st June 2012) in the European Union (EU) and the United States (US), of which 66 mentioned the term 'QT' (two EU only, 28 US only, 36 both). The agreement between authorities about the message on QT prolongation (does not prolong, unclear, possibly prolongs, prolongs) was moderate (kappa 0.434). However, the agreement in expected clinical decisions based on the product labels was much higher (kappa 0.673). The US drug label tends to be more explicit, especially when it considers absence of QT effects.
authors: Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, The Netherlands; Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Miriam J
authors: MJ
authors: Warnier
authors: Medicines Evaluation Board (CBG-MEB), Utrecht, The Netherlands; Department of Clinical Pharmacology, Graduate School of Medicine, University Medical Center Groningen, Groningen, The Netherlands.
authors: Frank A
authors: FA
authors: Holtkamp
authors: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Frans H
authors: FH
authors: Rutten
authors: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors: Arno W
authors: AW
authors: Hoes
authors: Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, The Netherlands.
authors: Anthonius
authors: A
authors: de Boer
authors: Medicines Evaluation Board (CBG-MEB), Utrecht, The Netherlands; Department of Clinical Pharmacology, Graduate School of Medicine, University Medical Center Groningen, Groningen, The Netherlands.
authors: Peter G M
authors: PG
authors: Mol
authors: Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht, The Netherlands; Medicines Evaluation Board (CBG-MEB), Utrecht, The Netherlands. Electronic address: m.l.debruin@uu.nl.
authors: Marie L
authors: ML
authors: De Bruin
mesh_terms: D004348:Drug Labeling / Q000706:statistics & numerical data*; D064420:Drug-Related Side Effects and Adverse Reactions; D005062:European Union; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced*; D014481:United States