Augmentin Dosing for Upper Respiratory Infection
Critical First Step: Confirm Bacterial Infection Before Prescribing
Do not prescribe antibiotics for uncomplicated viral upper respiratory infections (URIs), which account for 98–99.5% of acute respiratory illness and resolve spontaneously within 7–10 days. 1 Antibiotics are indicated only when acute bacterial rhinosinusitis (ABRS) is confirmed by at least one of the following patterns:
- 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
Standard Adult Dosing for Confirmed Bacterial Sinusitis
For otherwise healthy adults with acute bacterial sinusitis, prescribe amoxicillin-clavulanate 875 mg/125 mg orally twice daily for 5–10 days (or until symptom-free for 7 consecutive days, typically 10–14 days total). 1 This regimen provides 90–92% predicted clinical efficacy against the three major sinusitis pathogens: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 1
- Shorter courses (5–7 days) are equally effective with fewer adverse effects and are increasingly recommended. 1
- Take at the start of meals to minimize gastrointestinal intolerance. 2
High-Dose Regimen for Risk Factors
Use high-dose amoxicillin-clavulanate 2 g/125 mg (2000 mg/125 mg) twice daily when any of the following risk factors are present: 1
- Recent antibiotic use (past 4–6 weeks)
- Age >65 years
- Daycare exposure (patient or close contact)
- Moderate-to-severe symptoms
- Comorbidities (diabetes, chronic cardiac/hepatic/renal disease)
- Immunocompromised state
- Smoking or exposure to smoke
This high-dose regimen maintains therapeutic amoxicillin levels throughout the 12-hour dosing interval to eradicate resistant organisms. 1
Pediatric Dosing
Standard Dose (Uncomplicated Cases)
For children ≥3 months with uncomplicated bacterial sinusitis, prescribe amoxicillin 45 mg/kg/day divided into 2 doses for 10–14 days. 1
High-Dose (Risk Factors Present)
For children with risk factors (age <2 years, daycare attendance, antibiotic use within past 4–6 weeks, or high local resistance rates), prescribe high-dose amoxicillin-clavulanate 80–90 mg/kg/day (amoxicillin component) plus 6.4 mg/kg/day clavulanate divided into 2 doses for 10–14 days. 1
- Children weighing ≥40 kg should be dosed according to adult recommendations. 2
- The 14:1 ratio formulation (high-dose) causes less diarrhea than other amoxicillin-clavulanate preparations. 1
Renal Impairment Dosing
Patients with severe renal impairment require dose adjustments: 2
- GFR 10–30 mL/min: 500 mg/125 mg or 250 mg/125 mg every 12 hours (depending on severity)
- GFR <10 mL/min: 500 mg/125 mg or 250 mg/125 mg every 24 hours
- Hemodialysis patients: 500 mg/125 mg or 250 mg/125 mg every 24 hours, with an additional dose both during and at the end of dialysis 2
- Do not use the 875 mg/125 mg tablet in patients with GFR <30 mL/min. 2
Penicillin Allergy Alternatives
Non-Severe (Non-Type I) Allergy
Use a second- or third-generation cephalosporin for 10 days (e.g., cefuroxime-axetil, cefpodoxime-proxetil, cefdinir, cefprozil); cross-reactivity with penicillin is negligible. 1
Severe (Type I/Anaphylactic) Allergy
Use a respiratory fluoroquinolone: 1
- Levofloxacin 500 mg once daily for 10–14 days, or
- Moxifloxacin 400 mg once daily for 10 days
Both provide 90–92% predicted efficacy against multidrug-resistant S. pneumoniae and β-lactamase-producing organisms. 1
Avoid macrolides (azithromycin, clarithromycin) due to 20–25% resistance rates in S. pneumoniae and H. influenzae. 1
Essential Adjunctive Therapies (Add to All Patients)
Prescribe these alongside antibiotics to improve outcomes: 1
- Intranasal corticosteroids (mometasone, fluticasone, or budesonide) twice daily – reduce mucosal inflammation and accelerate symptom resolution (strong evidence from multiple RCTs)
- Saline nasal irrigation 2–3 times daily – provides symptomatic relief and clears mucus
- Analgesics (acetaminophen or ibuprofen) – for pain and fever control
Monitoring and Reassessment Protocol
Reassess at 3–5 Days
If no clinical improvement (persistent purulent drainage, unchanged facial pain, or worsening), immediately switch to: 1
- High-dose amoxicillin-clavulanate (2 g/125 mg twice daily), or
- A respiratory fluoroquinolone (levofloxacin or moxifloxacin)
Reassess at 7 Days
If symptoms persist or worsen, reconfirm the diagnosis, exclude complications (orbital cellulitis, meningitis, intracranial abscess), and consider imaging or ENT referral. 1
Expected Timeline
- Noticeable improvement within 3–5 days of appropriate therapy 1
- Complete resolution by 10–14 days or when symptom-free for 7 consecutive days 1
Critical Pitfalls to Avoid
- Do not prescribe antibiotics for symptoms <10 days unless severe features (fever ≥39°C with purulent discharge for ≥3 consecutive days) are present. 1
- Do not substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet – they contain the same amount of clavulanate (125 mg) and are not equivalent. 2
- Ensure minimum treatment duration (≥5 days for adults, ≥10 days for children) to prevent relapse. 1
- Gastrointestinal adverse effects are common – diarrhea occurs in 40–43% of patients, with severe diarrhea in 7–8%. 1
- Reserve fluoroquinolones for second-line therapy or documented severe β-lactam allergy to prevent resistance development. 1
When to Refer to Otolaryngology
Refer immediately if any of the following occur: 1
- No improvement after 7 days of appropriate second-line antibiotic therapy
- Worsening symptoms at any point during treatment
- Suspected complications (severe headache, visual changes, periorbital swelling, altered mental status, cranial nerve deficits)
- Recurrent sinusitis (≥3 episodes per year) requiring evaluation for underlying allergic rhinitis, immunodeficiency, or anatomic abnormalities