QT prolongation due to roxithromycin

Roxithromycin and other macrolide antimicrobials are widely used for a broad variety of infections such as upper respiratory tract infection and community acquired pneumonia. Prolongation of the QT interval, torsade de pointes polymorphic ventricular tachycardia, and sudden death are well described but little known adverse reactions common to all macrolides. We report the case of a 72 year old patient with congestive heart failure caused by ischaemic heart disease who developed severe prolongation of the QT interval after three days of treatment with roxithromycin. A 72 year old man presented with severe congestive heart failure. Three months earlier he had been diagnosed with three vessel coronary heart disease with moderately impaired left ventricular function. Thallium scans had failed to demonstrate a distinct area of ischaemia, hence a decision had been made to refrain from surgical treatment. Frusemide (furosemide), digoxin, captopril, and aspirin had been begun whereas metoprolol had to be discontinued because of bradycardia. In view of the impaired left ventricular function, amiodarone was started, instead of β blocker, after recurrent episodes of atrial fibrillation. On admission, the patient was severely dyspnoeic and appeared acutely ill. Physical examination revealed displacement of the apex beat, a prominent third heart sound, coarse rales over both lung fields and pitting oedema of both ankles. The patient was taken to an intensive care unit. Acute myocardial infarction was ruled out and frusemide was begun intravenously. An electrocardiogram (ECG) on admission showed sinus rhythm and incomplete left bundle branch block; QT …