The effects of erythromycin on the electrocardiogram.
BACKGROUND
Various cardiac electrophysiologic effects have been attributed to erythromycin. During the course of treating a pneumonia patient with IV erythromycin, the conversion of atrial fibrillation to a sinus rhythm, and its subsequent reversal, appeared to be causally related to the introduction and cessation of this antibiotic.


OBJECTIVE
This observation suggested the need for studying the changes in the ECG following the use of IV erythromycin in a typical clinical setting.


METHODS
A prospective comparative drug study.


METHODS
A university-affiliated teaching hospital.


METHODS
Nineteen patients being treated for uncomplicated community-acquired pneumonia.


METHODS
IV erythromycin, 500 mg, and/or IV cefuroxime, 750 mg, infused in 250 mL of saline over 20 min. In the 11 patients who were receiving both of the antibiotics, cefuroxime was administered immediately before erythromycin was infused.


METHODS
The 12-lead ECG measurements were obtained before infusion, at 5-min intervals during each infusion, and at 5 and 10 min after the infusions had been completed. All of the ECG complexes and intervals were measured using a software program (Interpretive Cardiograph; Hewlett Packard; Palo Alto, CA).


RESULTS
The administration of IV erythromycin increased heart rate and prolonged the corrected QT (QTc) interval. These changes were significant at 15 min of the infusion, and were no longer evident 5 min after the infusion had been stopped. The administration of IV cefuroxime did not produce any ECG changes.


CONCLUSIONS
A single, standard dose of IV erythromycin prolongs the QTc interval; therefore, the drug should always be administered as a slow infusion. ECG monitoring should accompany erythromycin therapy in critically ill patients, in patients with electrolyte disorders, or in patients taking other drugs with similar cardiac effects.
Mishra
A
A
Department of Medicine, Long Island College Hospital, Brooklyn, NY, USA.
Friedman
H S
HS
Sinha
A K
AK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002444:Cefuroxime / Q000494:pharmacology / Q000627:therapeutic use; D002511:Cephalosporins / Q000494:pharmacology / Q000627:therapeutic use; D004562:Electrocardiography / Q000187:drug effects*; D004917:Erythromycin / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000188:drug therapy / Q000503:physiopathology; D011446:Prospective Studies
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D004917:Erythromycin; D002444:Cefuroxime