Sick Sinus Syndrome After a Single Oral Administration of Garenoxacin

This report presents the case of a 60-year-old female who demonstrated sick sinus syndrome after a single administration of Garenoxacin (GRNX). She was administered GRNX for an upper respiratory infection and 10 minutes thereafter, she suddenly felt palpitation and numbness of both arms. She was transferred to the hospital 2 hours after taking GRNX. An electrocardiogram showed bradycardia with junctional escape beats and the longest sinus arrest was 4 seconds. She was treated with a temporary pacemaker and 21 hours after the administration of GRNX her sinus node function was observed to have completely improved. GRNX-induced sick sinus syndrome was suspected because her clinical course was compatible with the concentration of GRNX and her other cardiological assessments, including an electrophysiologic study (EPS) which were conducted on the 9th day of the admission, were normal. GRNX has less effect on the QT interval than other quinolone agents. However, physicians should be aware of the risk of sick sinus syndrome because GRNX is frequently prescribed in outpatient clinics.