Augmentin Duration for Sinusitis

For an otherwise healthy adult with acute bacterial sinusitis, prescribe Augmentin (amoxicillin-clavulanate) 875 mg/125 mg twice daily for 5–7 days, which provides equivalent clinical efficacy to traditional 10–14 day courses with fewer adverse effects. 1

Confirming the Diagnosis Before Prescribing

Before initiating antibiotics, confirm that the patient meets at least one of three diagnostic criteria for acute bacterial rhinosinusitis (ABRS):

Persistent symptoms ≥ 10 days without improvement (purulent nasal discharge plus nasal obstruction or facial pain/pressure). 1
Severe symptoms ≥ 3–4 consecutive days with fever ≥ 39°C, purulent nasal discharge, and facial pain. 1
"Double sickening": initial improvement from a viral URI followed by worsening symptoms within 10 days. 1

Critical pitfall: Approximately 98–99.5% of acute rhinosinusitis cases are viral and resolve spontaneously within 7–10 days without antibiotics. 1 Do not prescribe antibiotics for symptoms lasting < 10 days unless the severe criteria above are met. 1

Standard Dosing Regimen

Augmentin 875 mg/125 mg orally twice daily is the preferred first-line regimen for otherwise healthy adults. 1, 2, 3
Treatment duration: 5–7 days for uncomplicated cases. 1 Recent evidence demonstrates that shorter courses (5–7 days) achieve clinical cure rates of 74–80%, comparable to 10-day regimens, with no difference in microbiological eradication or relapse. 1
An alternative approach is to continue therapy until the patient is symptom-free for 7 consecutive days, which typically results in a 10–14 day total course. 1, 3

Evidence strength: The IDSA guideline provides a weak recommendation with low-moderate quality evidence for 5–7 day courses in adults. 1 However, randomized controlled trials support this shorter duration with comparable efficacy and fewer adverse effects. 1

High-Dose Regimen for Specific Risk Factors

Use high-dose Augmentin (2 g amoxicillin/125 mg clavulanate twice daily) when any of the following risk factors are present:

Recent antibiotic use within the past 4–6 weeks 1, 2
Age > 65 years 1, 2
Daycare attendance or close contact with daycare children 1, 2
Moderate-to-severe symptoms 1, 2
Comorbidities (diabetes, chronic cardiac/hepatic/renal disease) 1, 2
Immunocompromised state 1, 2
High local prevalence of drug-resistant Streptococcus pneumoniae 1, 2

Rationale: The higher amoxicillin dose (2 g vs. 875 mg) enhances coverage against penicillin-resistant S. pneumoniae while maintaining activity against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis. 1, 2

Monitoring and Reassessment Protocol

Reassess at 3–5 days: If there is no clinical improvement (persistent purulent drainage, unchanged facial pain, or worsening), switch immediately to a second-line agent (respiratory fluoroquinolone such as levofloxacin 500 mg once daily or moxifloxacin 400 mg once daily). 1, 2
Reassess at 7 days: Persistent or worsening symptoms warrant confirmation of diagnosis, exclusion of complications (orbital cellulitis, meningitis, intracranial abscess), and consideration of imaging or ENT referral. 1, 2

Expected timeline: Only 30–41% of patients show improvement by days 3–5; zero improvement at this point indicates treatment failure. 2 By day 7, approximately 73–85% of patients show clinical improvement even with placebo. 2

Essential Adjunctive Therapies (Add to All Patients)

Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily significantly reduce mucosal inflammation and accelerate symptom resolution. This recommendation is supported by strong evidence from multiple randomized controlled trials. 1, 2, 3
Saline nasal irrigation 2–3 times daily provides symptomatic relief and aids mucus clearance. 1, 2, 3
Analgesics (acetaminophen or ibuprofen) for pain and fever control. 1, 2, 3

Watchful Waiting as an Alternative Strategy

For adults with uncomplicated ABRS and reliable follow-up, initial observation without antibiotics is appropriate. 1, 2 Initiate antibiotics only if:

No improvement by day 7, or
Symptoms worsen at any time. 1, 2

Number needed to treat (NNT): 10–15 patients must receive antibiotics to achieve one additional cure compared with placebo. 1, 2 This reflects the high rate of spontaneous recovery in bacterial sinusitis.

Common Adverse Effects

Diarrhea occurs in 40–43% of patients taking amoxicillin-clavulanate; severe diarrhea in 7–8%. 1, 2, 4
Gastrointestinal adverse effects are more common with amoxicillin-clavulanate compared to other antibiotics. 1, 4
One randomized trial found that high-dose IR (immediate-release) amoxicillin-clavulanate (1750 mg amoxicillin twice daily) caused severe diarrhea in 15.8% of patients vs. 4.8% with standard-dose (P = 0.048). 5

Alternatives for Penicillin-Allergic Patients

Non-severe (non-Type I) penicillin allergy: Use a second- or third-generation cephalosporin (cefuroxime-axetil, cefpodoxime-proxetil, cefdinir, or cefprozil) for 10 days. Cross-reactivity with penicillins is negligible. 1, 2
Severe (Type I/anaphylactic) penicillin allergy: Use a respiratory fluoroquinolone—levofloxacin 500 mg once daily for 10–14 days or moxifloxacin 400 mg once daily for 10 days—with 90–92% predicted efficacy against multidrug-resistant S. pneumoniae. 1, 2
Doxycycline 100 mg once daily for 10 days is an acceptable but suboptimal alternative (predicted efficacy 77–81% with a 20–25% bacteriologic failure rate). 1, 2

Antibiotics to Avoid

Macrolides (e.g., azithromycin): 20–25% resistance rates in S. pneumoniae and H. influenzae make them unsuitable. 1, 2
Trimethoprim-sulfamethoxazole: 50% resistance in S. pneumoniae and 27% in H. influenzae. 1, 2
First-generation cephalosporins (e.g., cephalexin): Inadequate against H. influenzae because ~50% of strains produce β-lactamase. 1, 2

Pediatric Considerations

Children require 10–14 days of treatment, as current pediatric data do not support shorter durations. 1, 2
Standard-dose amoxicillin: 45 mg/kg/day divided twice daily. 1, 2
High-dose amoxicillin: 80–90 mg/kg/day divided twice daily for children < 2 years, those attending daycare, or with recent antibiotic exposure. 1, 2
High-dose amoxicillin-clavulanate: 80–90 mg/kg/day (amoxicillin component) plus 6.4 mg/kg/day clavulanate divided twice daily. 1, 2
Reassess at 72 hours: If no improvement or worsening, switch to high-dose amoxicillin-clavulanate. 1, 2

Referral to Otolaryngology

Refer immediately if any of the following occur:

No improvement after 7 days of appropriate second-line antibiotic therapy. 1, 2
Worsening symptoms at any point during treatment. 1, 2
Suspected complications (severe headache, visual changes, periorbital swelling/erythema, proptosis, diplopia, altered mental status, cranial nerve deficits). 1, 2
Recurrent sinusitis (≥ 3 episodes per year) requiring evaluation for underlying allergic rhinitis, immunodeficiency, or anatomic abnormalities. 1, 2

Key Pitfalls to Avoid

Do not extend treatment beyond 7 days without clinical justification, as this raises the incidence of severe diarrhea (≈ 7–8%) without improving outcomes. 1, 2
Do not prescribe antibiotics for symptoms lasting < 10 days unless severe features are present (fever ≥ 39°C with purulent discharge for ≥ 3 consecutive days). 1, 2
Maintain a minimum 5-day course even if symptoms improve earlier, to prevent relapse and resistance development. 1, 2
Do not obtain routine imaging (X-ray or CT) for uncomplicated ABRS; up to 87% of viral upper-respiratory infections show sinus abnormalities on imaging, leading to unnecessary interventions. 1, 2

For an otherwise healthy adult with acute bacterial sinusitis, what is the recommended Augmentin (amoxicillin‑clavulanate) dosage and treatment duration?

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