[Cefixime, the first oral third-generation cephalosporin]

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Parenteral third-generation cephalosporins revolutionized hospital antibiotic use in the early 1980s due to their low minimum inhibitory concentrations (MICs) against Enterobacteriaceae and enhanced beta-lactamase stability.
• Development of orally active antibiotics with similar efficacy to parenteral third-generation cephalosporins was a significant research goal.

Purpose of the Study:

• To introduce cefixime as an orally active cephalosporin with third-generation parenteral-like antibacterial activity.
• To describe the structural features and absorption mechanisms of cefixime.
• To outline the clinical efficacy and safety of cefixime for various infections in adults.

Main Methods:

• Cefixime was developed through molecular modification to achieve oral activity.
• The role of the vinyl group at the 3-position for intestinal absorption via carrier-mediated transport was identified.
• The contribution of the aminothiazole ring and R-oxyimino group at the 7-position to antibacterial activity was established.

Main Results:

• Cefixime demonstrates antibacterial activity comparable to parenteral third-generation cephalosporins.
• Clinical studies in thousands of adults confirm cefixime's safety and efficacy.
• Effective treatment of lower respiratory tract, ear-nose-throat, and urinary tract infections was observed.

Conclusions:

• Cefixime is a safe and effective oral antimicrobial agent.
• Key indications include bronchial and pulmonary infections, acute otitis/sinusitis, and urinary tract infections (excluding prostatitis).
• The standard dosage for cefixime is 200 mg twice daily (b.i.d).