Role of Cefixime and Cefadroxil in Upper Respiratory Tract Infections
Cefixime is not recommended for upper respiratory tract infections due to its inactivity against pneumococci with decreased susceptibility to penicillin, while cefadroxil can be used as a first-line option for pharyngitis and tonsillitis caused by Streptococcus pyogenes. 1, 2
Cefixime in Upper Respiratory Tract Infections
Indications and Limitations
- Cefixime is FDA-approved for otitis media, pharyngitis/tonsillitis, and acute exacerbations of chronic bronchitis in patients six months of age or older 3
- Despite being a third-generation cephalosporin, cefixime is specifically not recommended for respiratory infections where pneumococci with decreased penicillin susceptibility are suspected due to its inactivity against these strains 1
- For sinusitis treatment, guidelines explicitly exclude cefixime from the recommended third-generation cephalosporins, while recommending cefpodoxime-proxetil and cefotiam-hexetil instead 1
Clinical Evidence
- In respiratory tract infections, cefixime has shown favorable clinical response rates (99-100%) and bacteriological eradication rates (93-100%) for susceptible organisms 4
- For acute otitis media caused by Streptococcus pneumoniae, overall response was approximately 10% lower for cefixime compared to other antibiotics 3
- While cefixime has demonstrated efficacy in treating acute otitis media (100% success rate in one study), its use should be guided by local susceptibility patterns 5
Cefadroxil in Upper Respiratory Tract Infections
Indications and Role
- Cefadroxil is FDA-approved for pharyngitis and tonsillitis caused by Streptococcus pyogenes (Group A beta-hemolytic streptococci) 2
- As a first-generation cephalosporin, cefadroxil can be used as a first-line antibiotic for exacerbations of chronic bronchitis when there are infrequent exacerbations 1
- Clinical studies have demonstrated high success rates (100%) in upper respiratory tract infections 6
Clinical Evidence
- In comparative studies, cefadroxil has shown slightly lower efficacy compared to newer cephalosporins like cefuroxime-axetil (90.4% vs 94.3% success rate) 7
- Cefadroxil achieved bacterial eradication in 91% of respiratory pathogens in clinical studies 6
Treatment Algorithm for Upper Respiratory Tract Infections
Acute Sinusitis
- For maxillary sinusitis: Use amoxicillin-clavulanate, second-generation (cefuroxime-axetil) or specific third-generation cephalosporins (cefpodoxime-proxetil, cefotiam-hexetil) - NOT cefixime 1
- For frontal, ethmoidal, or sphenoidal sinusitis: Consider fluoroquinolones active against pneumococci (levofloxacin, moxifloxacin) in addition to the above options 1
- Duration of treatment: 7-10 days generally; cefuroxime-axetil and cefpodoxime-proxetil have shown efficacy in 5-day regimens 1
Pharyngitis and Tonsillitis
- Cefadroxil is effective for pharyngitis/tonsillitis caused by S. pyogenes 2
- Cefixime can be used for pharyngitis/tonsillitis but note that penicillin remains the drug of choice for S. pyogenes infections 3
- For S. pyogenes infections, antibiotic therapy should be administered for at least 10 days 3
Otitis Media
- For otitis media in children under 2 years: Antibiotic therapy is recommended 1
- For children over 2 years: Antibiotics may be withheld except in cases with marked symptoms 1
- Cefixime suspension (not tablets) is recommended for otitis media due to higher peak blood levels 3
- Cefadroxil has shown efficacy but is not specifically mentioned in guidelines for this indication 6
Important Clinical Considerations
Antimicrobial Resistance Concerns
- The increasing prevalence of bacterial resistance necessitates careful antibiotic selection 1
- Fluoroquinolones should be reserved for situations where major complications are likely or after first-line treatment failure 1
Common Pitfalls
- Using cefixime for infections where pneumococci with decreased susceptibility to penicillin are suspected - this should be avoided 1
- Substituting tablets for suspension in the treatment of otitis media with cefixime - the suspension provides higher peak blood levels 3
- Failing to complete the full course of therapy - for S. pyogenes infections, treatment should continue for at least 10 days to prevent rheumatic fever 3, 2
- Not considering local epidemiology and susceptibility patterns when selecting therapy 3