For an 18-year-old patient with a history of otitis media, presenting with throat ache, tonsillitis and low-grade fever, which IV antibiotic is more appropriate, ceftriaxone 1 gram or Cefazolin 1 gram?

Neither Ceftriaxone Nor Cefazolin is Appropriate for Uncomplicated Acute Tonsillitis

For an 18-year-old with throat ache, +3 tonsils, and low-grade fever, IV antibiotics are not indicated—oral antibiotics are the standard of care, and if IV therapy is absolutely necessary, ceftriaxone 1 gram IV daily would be the only reasonable choice between your two options, though cefazolin has no role in pharyngotonsillitis treatment. 1, 2

Why IV Antibiotics Are Not Indicated

• Acute bacterial tonsillitis (presumed Group A Streptococcus) is effectively treated with oral antibiotics in immunocompetent patients 2
• IV antibiotics are reserved for patients who cannot tolerate oral medications, have severe systemic toxicity, or have failed oral therapy 1
• The history of otitis media does not change the treatment approach for acute tonsillitis 3, 2

If IV Therapy Is Absolutely Required

Ceftriaxone Would Be the Choice

• Ceftriaxone 1-2 grams IV daily provides appropriate coverage for respiratory tract infections including pharyngitis 1
• Ceftriaxone achieves excellent tissue penetration and covers Streptococcus pyogenes (Group A Strep), the primary pathogen in bacterial tonsillitis 1, 4
• The American Academy of Otolaryngology-Head and Neck Surgery recommends ceftriaxone 1-2 g/day for moderate respiratory infections 1

Why Cefazolin Is Inappropriate

• Cefazolin is a first-generation cephalosporin designed primarily for skin/soft tissue infections and surgical prophylaxis, not respiratory tract infections 5
• Cefazolin has poor penetration into respiratory tissues compared to ceftriaxone 4
• Guidelines for respiratory infections do not include cefazolin as a treatment option 1, 2
• The only mention of cefazolin in relevant guidelines is for endocarditis treatment, not pharyngitis 5

The Correct Approach

Oral Therapy Should Be First-Line

• Oral amoxicillin or penicillin V remains the first-choice antibiotic for acute bacterial tonsillitis 2, 6
• If penicillin allergy exists, oral cephalosporins (cefdinir, cefpodoxime) or macrolides are appropriate alternatives 2

When to Consider IV Therapy

• Patient unable to swallow or tolerate oral medications 1
• Severe systemic toxicity with high fever, dehydration, or sepsis 1
• Peritonsillar abscess or deep space neck infection requiring drainage 1
• Failed outpatient oral antibiotic therapy with worsening symptoms 1, 3

Transition Strategy

• If IV ceftriaxone is initiated, transition to oral antibiotics after 48-72 hours once clinical improvement is documented (temperature <38°C, improved dysphagia, adequate oral intake) 1
• Total treatment duration should be 5-10 days depending on clinical response 1

Critical Pitfalls to Avoid

• Do not use IV antibiotics for routine uncomplicated tonsillitis—this promotes antibiotic resistance and unnecessary healthcare costs 2, 6
• Do not use cefazolin for respiratory tract infections—it lacks appropriate spectrum and tissue penetration 5, 4
• Do not continue IV therapy beyond 48-72 hours if the patient can tolerate oral medications 1
• Reassess at 48-72 hours for clinical improvement; if no improvement, consider alternative diagnoses (viral infection, mononucleosis, peritonsillar abscess) 1, 3