From the Guidelines
Third generation oral cephalosporins, such as cefdinir, cefpodoxime, and cefixime, are effective broad-spectrum antibiotics for treating various infections, including respiratory tract infections, otitis media, sinusitis, and uncomplicated urinary tract infections, with a low cross-reactivity rate in patients with penicillin allergies, as reported in a 2022 study 1.
Key Characteristics
- These medications are effective against many gram-negative bacteria, including Haemophilus influenzae, Moraxella catarrhalis, and some Enterobacteriaceae, while maintaining activity against gram-positive organisms like Streptococcus pneumoniae.
- Typical adult dosing for cefdinir is 300 mg twice daily or 600 mg once daily; for cefpodoxime 100-400 mg twice daily; and for cefixime 400 mg once daily, with all requiring adjustment for renal impairment.
- Treatment duration typically ranges from 5-14 days depending on the infection.
Advantages and Limitations
- They offer advantages over first and second generation cephalosporins through their enhanced gram-negative coverage and beta-lactamase stability.
- However, they have limited activity against Pseudomonas, anaerobes, and MRSA.
- Common side effects include diarrhea, nausea, and allergic reactions, with cross-reactivity possible in patients with penicillin allergies, although a study found that the reaction rate among patients with a confirmed penicillin allergy was only 0.8% (95% CI: 0.13%-4.1%) 1.
Clinical Use
- These medications are commonly used for respiratory tract infections, otitis media, sinusitis, and uncomplicated urinary tract infections.
- According to a 2005 study, cefpodoxime and cefdinir are suitable agents for acute bacterial sinusitis, while cefixime and ceftibuten have poor activity against S pneumoniae and are not recommended for this indication 2.
From the FDA Drug Label
Cefixime is a semisynthetic, cephalosporin antibacterial for oral administration. The answer is: Cefixime is a third generation oral cephalosporin 3.
From the Research
Characteristics of Third Generation Oral Cephalosporin
- Cefixime is a new orally active third-generation cephalosporin with a broad spectrum of activity against a variety of both gram-positive and -negative bacteria, including many beta-lactamase-producing strains of streptococci, Haemophilus influenzae, Neisseria gonorrhoeae, and the majority of the Enterobacteriaceae 4.
- The relatively long elimination half-life of cefixime (approximately 3.0 h) has made possible once- to twice-daily administration with the potential added benefit of improved patient compliance 4.
- Cefixime has high activity against basic pathogens of urogenital infection, and presents in high concentrations in the urine, kidneys, and urinary tract 5.
Clinical Efficacy
- Clinical trials indicate that cefixime is at least as effective as standard agents in the treatment of genitourinary and upper respiratory tract infections 4.
- Cefixime has been found to be highly effective in treating urogenital infections, with a cure rate of 97% for urogenital infection, 97% for rectal infection, and 89% for pharyngeal infection 6.
- A randomized clinical trial has found that cefixim has higher clinical and microbiological efficacy than ciprofloxacin in patients with acute uncomplicated cystitis 5.
- Cefixime has also been found to be effective in treating respiratory tract infections, including acute sinusitis, acute otitis media, and acute exacerbations of chronic bronchitis 7.
Safety and Tolerance
- Adverse reactions observed during clinical trials were relatively uncommon and generally mild and transient in nature, with the most significant adverse reactions being diarrhea and stool changes occurring in up to 20 percent of patients 4.
- The tolerance of cefixime was similar to that of the comparative drugs, but a once daily dose (400 mg) showed a higher incidence of gastrointestinal adverse effects than a twice daily dose (200 mg) 8.