Comparative Pharmacology
Head-to-head clinical analysis: E E S versus ZITHROMAX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: E E S versus ZITHROMAX.
E.E.S. vs ZITHROMAX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Erythromycin (E.E.S.) binds to the 50S subunit of bacterial ribosomes, inhibiting peptide chain elongation and protein synthesis. It also exhibits prokinetic effects on the gastrointestinal tract via motilin receptor agonism.
Azithromycin is a macrolide antibiotic that binds to the 50S ribosomal subunit of susceptible bacteria, inhibiting protein synthesis by preventing translocation of peptides. It also has immunomodulatory and anti-inflammatory effects.
250-500 mg every 6 hours orally or 15-20 mg/kg/day IV divided every 6 hours.
500 mg orally once daily for 3 days, or 2 g orally as a single dose for certain infections.
None Documented
None Documented
1.5-2 hours in adults with normal renal function; prolonged to 4-6 hours in patients with hepatic impairment; may be shorter in children.
Terminal elimination half-life of approximately 68 hours (range 35-96 hours), allowing once-weekly dosing for some indications.
Primarily hepatic (biliary) excretion of unchanged drug and active metabolites; approximately 15% of an oral dose is excreted unchanged in urine. The remainder is eliminated via feces as unchanged drug and metabolites.
Primarily eliminated via biliary/fecal route (∼50-60% as unchanged drug); renal excretion accounts for ∼12% of the dose; minimal metabolism.
Category C
Category C
Macrolide Antibiotic
Macrolide Antibiotic