0425: Predictive factors of side effects of amiodarone in the amiotox registry

Abstract

Amiodarone is a widely used antiarrhythmic drug in Tunisia and worldwide. However, its side effects are quite frequent hampering its use despite its efficacy. The purpose of our study was to determin the prevalence of amiodarone side effects and to analyse its predictors in our population. From May 1 st 2010 to April 30 th 2012, 200 consecutive patients (mean age: 61.9 ± 12.9 years) were included. Mean duration of amiodarone therapy was 51.9 ± 48.4 months with a mean dose of 288.1 ± 274.2 g. Atrial fibrillation (81.5%) was the most common indication. Amiodarone side effects occurred in 144 patients (72%). Refering to multivariate analysis, independent predictors were: – Advanced age (p=0.02), treatment duration (p<0.001) and cumulative dose (p<0.001) for occurrence of all side effects. – Treatment duration > 6 months (p=0.008) for corneal deposits. – Age >70 years (p=0.001) and cumulative dose (p<0.00.1 with a logarithmic correlation) for thyroid toxicity. – Cumulative dose (p<0.001) and thyroid disease history (p=0.047) for hypothyroidism. – Age >70 years (p=0.002) and treatment duration (p<0.001 with a linear correlation) for cutaneous toxicity. – Cumulative dose >300 g (p = 0.012) and heart failure (p= 0.05) for bradycardia. – Cumulative dose >100 g (p= 0.012) for QT prolongation – Treatment duration (p<0.001 with a linear correlation) and betablokers concomittent use (p=0.046) for PR elongation. – Treatment duration (p<0.001 with an exponential correlation) and concomittent VKA use (p=0.018) for hepatic toxicity. – Treatment duration > 18 months (p=0.009) and concomittent CCB use (p<0.001) for neurological toxicity. The results of our study confirmed that amiodarone side effects are quite frequent in our population, and that in addition to treatment dose and duration, other predictors for these effects were identified such as age and some drug associations.