OBJECTIVES: This signal detection pharmacovigilance activity aims to determine if treatment with desloratadine is associated with more than expected reporting of torsade de pointes and electrocardiogram QT prolongation (TQP) events in real-world settings. METHODS: Adverse event reports submitted to the FDA Adverse Event Reporting System were used (cumulative to June 2014), and Multi-item Gamma Poisson Shrinker disproportionality analysis algorithm was applied to calculate Empirical Bayes Geometric Mean (EBGM) and corresponding 95%CI as association metrics. Desloratadine was defined by generic name, and ventricular tachycardia events were defined as structured MedDRA queries of Preferred Terms denoting to TQP. Reporting profile was compared to loratadine, the parent drug of desloratadine. Arrhythmogenic antihistamines, astemizole and terfenadine, were used as positive controls. RESULTS: Seventeen reports of TQP were submitted for desloratadine corresponding to 59% male users (mean age 44 years), and 17% and 35% of TQP events were life-threatening and lead to patient hospitalization, respectively. For loratadine, a total of 147 TQP reports were submitted, corresponding to 61% male users (mean age 51 years), and 8% and 36% of TQP events were fatal and life-threatening, respectively; 65% of reported events contributed to patient hospitalization. On average, desloratadine and loratadine users used 3 concomitant medications at the time of TQP occurrence. Reporting of TQP for desloratadine users was more than expected (EBGM=1.70; 95%CI=1.13-2.48), but a stronger signal was found for loratadine users (EBGM=3.65; 95%CI=3.18-4.17). Astemizole and terfenadine were associated with significant signals of TQP (EBGM=20.1; 95%CI=17.3-23.3 and EBGM=15.0; 95%CI=13.6-16.4, respectively). CONCLUSIONS: Anti-allergy treatment with desloratadine might be associated with TQP. A non-arrhythmogenic antihistamine might be an alternative therapy in patients at risk of ventricular tachycardias. Cardiac conduction monitoring might be recommended in desloratadine users.