Atrioventricular block induced by hydroxychloroquine

Abstract

A 48-year-old male patient received oral hydroxychloroquine 100 mg thrice daily, oral total glucosides of white paeony 60 mg twice daily, and intravenous infusion of methylprednisolone 40 mg once daily, which was replaced by oral prednisone 45 mg once daily 10 days later. The electrocardiogram of the patient was normal before the medication. On day 11 of medication, the patient developed palpitation about 2 hours after taking hydroxychloroquine. His electrocardiogram showed atrioventricular block, which returned to normal about 2 hours later. Then the patient was monitored by dynamic electrocardiogram. On day 17, the patient developed palpitation again about 2 hours after taking hydroxychloroquine and the dynamic electrocardiogram showed atrioventricular block, atrial premature beat, and occasional premature ventricular beat. These symptoms were considered to be related to hydroxychloroquine. Then hydroxychloro-quine was discontinued and other drugs were continued. Metoprolol sustained-release tablets 23.75 mg were given once daily. On day 3 of hydroxychloroquine withdrawal, the patient had normal electrocardiogram. At 9 days of follow-up, palpitation and atrioventricular block did not recur. Key words: Hydroxychloroquine; Atrioventricular block; Lupus erythematosus, systemic