Antimicrobials and QT prolongation

Area of Science:

• Pharmacology
• Cardiology
• Microbiology

Background:

• Antimicrobials, particularly macrolides, pose a significant risk for cardiac arrhythmias due to QT prolongation.
• This risk stems from their interaction with the IKr potassium channel and potential drug metabolism interference.
• Practitioners often overlook the cardiac risks associated with antimicrobial prescribing.

Purpose of the Study:

• To investigate the QT-prolonging effects of solithromycin, a novel ketolide antibiotic.
• To compare the cardiac safety profile of ketolides versus traditional macrolides.
• To highlight the need for increased awareness regarding antimicrobial-induced cardiac arrhythmias.

Main Methods:

• Evaluation of solithromycin's effect on the QT interval.
• Comparison of QT effects among solithromycin, other ketolides, and macrolides.
• Review of antimicrobial mechanisms affecting cardiac ion channels and drug metabolism.

Main Results:

• Solithromycin demonstrated a lack of significant QT-prolonging effect, contrary to expectations for macrolide antibiotics.
• Other tested ketolides also exhibited minimal QT prolongation.
• The keto substitution in ketolides appears to be the structural basis for their improved cardiac safety.

Conclusions:

• Ketolides, including solithromycin, represent a safer alternative to macrolides for patients susceptible to QT prolongation and cardiac arrhythmias.
• Enhanced medical education is crucial to address the underestimation of antimicrobial cardiac risks.
• Consideration of ketolides is recommended when macrolides are indicated in at-risk patients.