Moxifloxacin Causing Lazy Heart: A Case Report

Bradycardia is defined as heart rate less than 60bpm in adults (Normal heart rate is 60-100bpm in adults). There are many causes of bradycardia including medications which can cause mild to severe depression in heart rate even leading to cardiac arrest and death. Here is the case of an elderly man with no pre-morbid condition who took moxifloxacin for the treatment of acute rhinosinusitis. He developed dizziness and generalized fatigue on second day of antibiotic treatment. His complete blood picture, liver function tests, renal function tests, serum electrolytes including magnesium and potassium were all normal. ECG showed sinus bradycardia. Echocardiography was normal. His moxifloxacin was switched to amoxicillin-clavulanate and his bradycardia reverted back to normal.