Failure of two macrolide antibiotics to prevent post-extraction bacteraemia

Area of Science:

• Pharmacology
• Microbiology
• Infectious Diseases

Background:

• Bacteraemia following dental extractions can lead to serious infections.
• Macrolide antibiotics like erythromycin and josamycin are sometimes considered for prophylaxis.
• The efficacy of these macrolides in preventing post-extraction bacteraemia requires investigation.

Purpose of the Study:

• To compare the efficacy of erythromycin and josamycin in preventing post-dental extraction bacteraemia.
• To assess the in vitro activity of these macrolides against streptococcal isolates.
• To determine serum drug levels achieved after oral administration.

Main Methods:

• A double-blind trial was conducted in healthy patients undergoing dental extractions.
• An in vitro blood culture system was used to evaluate bacterial survival.
• Minimum inhibitory concentrations (MICs) were determined using an agar dilution technique.
• Serum drug concentrations were measured in volunteers and patients.

Main Results:

• Both erythromycin and josamycin achieved satisfactory serum concentrations against streptococci.
• However, neither antibiotic prevented the survival of streptococcal strains in blood cultures for 24 hours.
• The study demonstrated a failure in prophylaxis under the tested conditions.

Conclusions:

• Erythromycin and josamycin are not effective for preventing post-dental extraction bacteraemia in this study.
• An alternative antibiotic prophylaxis is recommended for penicillin-allergic patients at risk of infective endocarditis.
• Further research into effective prophylactic agents against streptococcal bacteraemia is warranted.