What is the next step for a pediatric patient with bacterial sinusitis who did not improve after 72 hours of amoxicillin treatment?

Switch to Amoxicillin-Clavulanate

For a pediatric patient with bacterial sinusitis who has not improved after 72 hours of amoxicillin, the next step is to switch to high-dose amoxicillin-clavulanate, not refer to ENT. 1, 2

Why Switch Antibiotics at 72 Hours?

The 72-hour threshold is evidence-based and critical for treatment decisions in pediatric sinusitis:

• The American Academy of Pediatrics explicitly recommends reassessing children at 72 hours because clinical trial data demonstrate that patients who fail to improve by day 3 are unlikely to improve without intervention—only 9% of placebo-treated children showed improvement between days 3-10 after failing at day 3. 2

• Treatment failure at 72 hours suggests β-lactamase-producing organisms (such as Haemophilus influenzae or Moraxella catarrhalis) or drug-resistant Streptococcus pneumoniae, which amoxicillin alone cannot adequately cover. 1, 2

The Correct Next Step: High-Dose Amoxicillin-Clavulanate

Switch to high-dose amoxicillin-clavulanate at 90 mg/kg/day of the amoxicillin component (with 6.4 mg/kg/day clavulanate) divided twice daily. 1, 2, 3

• The clavulanate component provides essential coverage against β-lactamase-producing H. influenzae and M. catarrhalis, which are increasingly prevalent causes of treatment failure. 3, 4

• This regimen achieves 90-92% predicted clinical efficacy against resistant organisms. 1, 2

• Continue treatment for 10-14 days total or until symptom-free for 7 days. 1, 2

Why NOT Refer to ENT at This Stage?

ENT referral is NOT indicated for uncomplicated treatment failure at 72 hours. 2, 3

• ENT referral becomes necessary only when the child fails second-line antibiotic therapy (high-dose amoxicillin-clavulanate), develops complications (orbital cellulitis, intracranial extension), or has recurrent sinusitis. 1

• The American Academy of Pediatrics reserves specialist referral for patients who are seriously ill, immunocompromised, continue to deteriorate despite extended antimicrobial courses, or have recurrent episodes. 1

Alternative Second-Line Options (If Amoxicillin-Clavulanate Fails or Cannot Be Tolerated)

If the patient fails high-dose amoxicillin-clavulanate after another 72 hours or cannot tolerate it:

• Ceftriaxone 50 mg/kg IM/IV once daily for children unable to take oral medications, then switch to oral therapy after improvement. 1, 2

• Cefdinir, cefuroxime, or cefpodoxime for children with non-Type I penicillin hypersensitivity. 1, 4

• Clindamycin plus cefixime for penicillin-resistant S. pneumoniae coverage in communities with high resistance. 2

Critical Pitfalls to Avoid

• Do not continue ineffective amoxicillin beyond 72 hours. Delaying appropriate antibiotic change risks progression to complications. 2

• Reassess to confirm the diagnosis is truly bacterial sinusitis rather than viral upper respiratory infection or other non-bacterial causes. 1, 2

• Do not obtain imaging (CT or MRI) for uncomplicated treatment failure, as imaging does not contribute to diagnosis in straightforward cases. 2

• Reassess again at 72 hours after switching to amoxicillin-clavulanate. If still no improvement, consider complications, alternative diagnosis, or referral to otolaryngology. 3

Adjunctive Therapies to Enhance Recovery

• Intranasal corticosteroids reduce mucosal inflammation and improve symptom resolution. 2, 3

• Saline nasal irrigation helps improve mucociliary clearance. 3

• Analgesics (acetaminophen, ibuprofen) for pain and fever management. 1