What is the recommended treatment with Augmentin (amoxicillin-clavulanate) for a patient with sinusitis and respiratory infection, considering potential allergies to penicillin or other beta-lactam antibiotics?

Augmentin for Sinusitis and Respiratory Infection

Amoxicillin-clavulanate (Augmentin) 875 mg/125 mg twice daily for 5-10 days is the preferred first-line antibiotic for acute bacterial sinusitis in adults, providing optimal coverage against beta-lactamase-producing organisms (Haemophilus influenzae, Moraxella catarrhalis) and drug-resistant Streptococcus pneumoniae. 1, 2, 3

When to Start Antibiotics

Before prescribing, confirm the diagnosis meets one of three bacterial criteria: 1, 4

• Persistent symptoms ≥10 days without improvement (nasal discharge, congestion, facial pain/pressure, or cough) 1, 4
• Severe symptoms for ≥3 consecutive days (fever ≥39°C/102°F with purulent nasal discharge) 1, 4
• "Double sickening" - worsening after initial improvement from a viral upper respiratory infection 1, 4

Critical pitfall: 98-99.5% of acute rhinosinusitis is viral and resolves spontaneously within 7-10 days without antibiotics—do not prescribe for symptoms <10 days unless severe. 1

Standard Dosing for Adults

For uncomplicated cases: Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5-10 days 1, 2, 5

For high-risk patients (recent antibiotic use within past month, age >65 years, moderate-to-severe symptoms, comorbidities like diabetes/immunosuppression, or geographic areas with high penicillin-resistant S. pneumoniae): High-dose amoxicillin-clavulanate 2000 mg/125 mg twice daily 3, 6

Administration: Take at the start of meals to minimize gastrointestinal side effects and enhance clavulanate absorption. 5

Pediatric Dosing

Standard therapy: Amoxicillin-clavulanate 45 mg/kg/day (of amoxicillin component) divided twice daily 1, 5

High-dose therapy (for children <2 years, daycare attendance, recent antibiotic use, or areas with resistant S. pneumoniae): 90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate divided twice daily 1, 3, 6

Duration: 10-14 days or continue for 7 days after symptom resolution 3

For Patients with Penicillin Allergy

Non-severe/delayed-type allergy (rash, mild reactions): Second- or third-generation cephalosporins are safe and preferred 1, 2

• Cefuroxime-axetil (second-generation): effective in 5-day courses 1, 2
• Cefpodoxime-proxetil or cefdinir (third-generation): superior activity against H. influenzae, effective in 5 days 1, 2, 7

Severe/Type I hypersensitivity (anaphylaxis): Respiratory fluoroquinolones 1, 3

• Levofloxacin 500 mg once daily for 10-14 days 1, 3
• Moxifloxacin 400 mg once daily for 10 days 1, 3

What NOT to use: Azithromycin and other macrolides have 20-25% resistance rates for S. pneumoniae and H. influenzae—explicitly contraindicated as first-line therapy. 1, 7

Treatment Failure Protocol

Reassess at 3-5 days: If no improvement or worsening symptoms, switch antibiotics immediately. 1, 2, 3

Second-line options: 1, 2

• High-dose amoxicillin-clavulanate 2000 mg/125 mg twice daily (if not already used) 1
• Respiratory fluoroquinolones (levofloxacin 500-750 mg once daily or moxifloxacin 400 mg once daily) for 10-14 days 1, 2
• Ceftriaxone 1-2 g IM/IV once daily for 5 days (for patients unable to tolerate oral medications) 8, 1

At 7 days: If symptoms persist, reconfirm diagnosis and consider complications (orbital cellulitis, meningitis) or alternative diagnoses. 1

Essential Adjunctive Therapies

These improve outcomes regardless of antibiotic choice: 1, 3

• Intranasal corticosteroids (mometasone, fluticasone, or budesonide twice daily): reduce mucosal inflammation and improve symptom resolution 1, 3
• Saline nasal irrigation: improves sinus drainage and provides symptomatic relief 1, 3
• Analgesics (acetaminophen, ibuprofen): for pain and fever relief 1, 3
• Decongestants: provide symptomatic relief, but limit topical use to ≤3 days to avoid rhinitis medicamentosa 2

Expected Timeline for Improvement

• 3-5 days: Most patients should show noticeable improvement (reduced fever, facial pain, purulent discharge) 1
• 7 days: 73-85% of patients show clinical improvement 1
• 10-14 days: Complete resolution typically occurs by this timepoint 1, 3

If no improvement by 3-5 days, this constitutes treatment failure—switch antibiotics immediately. 1, 2

Critical Warnings and Contraindications

Hypersensitivity reactions: Serious and occasionally fatal anaphylactic reactions can occur—inquire about previous penicillin, cephalosporin, or other allergen hypersensitivity before prescribing. 5

Hepatic dysfunction: Monitor liver function in patients with hepatic impairment, as hepatitis and cholestatic jaundice have been reported (usually reversible). 5

Clostridium difficile-associated diarrhea (CDAD): Can occur with amoxicillin-clavulanate use—if suspected, discontinue and treat appropriately. 5

Mononucleosis: Do not administer to patients with mononucleosis due to high risk of erythematous skin rash. 5

Gastrointestinal effects: Most common adverse event is diarrhea (number needed to harm: 8.1)—taking medication at the start of meals minimizes this. 3, 5

Special Considerations by Anatomic Location

Maxillary sinusitis (most common): Standard first-line treatment with amoxicillin-clavulanate 1, 2

Frontal, ethmoidal, or sphenoidal sinusitis: Consider respiratory fluoroquinolones (levofloxacin or moxifloxacin) due to risk of serious complications like meningitis or brain abscess. 1, 2

When to Refer to a Specialist

Refer to otolaryngology for: 1, 4

• Symptoms refractory to two courses of appropriate antibiotics 1
• Recurrent sinusitis (≥3 episodes per year) 1
• Suspected complications (orbital cellulitis, meningitis, abscess) 1, 4
• Need for sinus aspiration/culture in immunocompromised patients 1