Azithromycin and Clarithromycin: Overview and Comparison with Erythromycin

Abstract

Macrolides currently account for 10% to 15% of the worldwide oral antibiotic market.' Erythromycin, the first macrolide antibiotic, was discovered in 1952 from a strain of Streptomyces erythreus obtained from soil samples in the Phillipines. Originally, erythromycin was marketed as an alternative to penicillin because of its activity against gram-positive organisms such as staphylococci, pneumococci, and streptococci. Subsequently, its clinical use broadened to include species of Mycoplasma, Legionella, Campylobacter, and Chlamydia. Although several other macrolides have been marketed in countries other than the United States, they have failed to achieve erythromycin's widespread use. Unfortunately, erythromycin suffers from several drawbacks, including gastrointestinal side effects, a short serum elimination half-life, and only borderline in vitro activity against common gram-negative respiratory pathogens such as Haemophilus influenzae.

Azithromycin inhibits macrophage interleukin-1β production through inhibition of activator protein-1 in lipopolysaccharide-induced murine pulmonary neutrophilia

“…Erythromycin, a secondary metabolite isolated from Saccharopolyspora erythraea, was the first macrolide to be introduced to clinical use over 50 years ago. Afterwards, several semisynthetic derivatives of erythromycin, like azithromycin (9-deoxy-9a-aza-9a-methyl-9a-homoerythromycin A), were designed to broaden the antimicrobial spectrum, reduce gastrointestinal side effects and increase acid stability and bioavailability of this class of antibiotics [1]. Macrolide antibacterials are broad-spectrum antibiotics that exhibit antibacterial activity against aerobic Gram-positive bacteria, certain Gram-negative bacteria, anaerobic bacteria and intracellular pathogens such as Mycoplasma, Chlamydia and Legionella [2].…”

Superiority of 11,12 Carbonate Macrolide Antibiotics as Inhibitors of Translation and 50S Ribosomal Subunit Formation in Staphylococcus aureus Cells

“…More recently a number of semisynthetic derivatives of erythromycin have been developed for use against additional microorganisms including Gram-negative pathogens [11]. Azithromycin, clarithromycin, and roxithromycin are three synthetic erythromycin derivatives currently being used against a number of different infectious diseases [21][22][23]. Each of these is more resistant to acid hydrolysis of the macrolactone ring than the parent compound.…”

Medications and Monitoring in Nontuberculous Mycobacteria Infections

“…Diarrhea, nausea/vomiting, and abdominal pain often are reported. 11 Switching macrolides (from clarithromycin to azithromycin, or vice versa) may be tried, or antiemetics may be tried if that fails. Azithromycin and clarithromycin are both associated with QT prolongation.…”