What is the treatment for tonsillitis exudates suspected to be of bacterial origin, specifically with Augmentin (amoxicillin-clavulanate)?

Treatment of Bacterial Tonsillitis with Augmentin

Augmentin (amoxicillin-clavulanate) is an effective alternative for bacterial tonsillitis, particularly when penicillin has failed or in recurrent cases, though penicillin remains the first-line treatment for uncomplicated Group A streptococcal pharyngitis. 1

First-Line Treatment Considerations

• Penicillin is the drug of choice for initial treatment of Group A streptococcal pharyngitis due to universal susceptibility, safety, low cost, and narrow spectrum. 1, 2
• All Group A streptococci remain susceptible to both penicillin and amoxicillin-clavulanate. 2
• Standard penicillin therapy requires a full 10-day course to achieve maximal pharyngeal eradication. 1

When to Use Augmentin

Augmentin should be considered in specific clinical scenarios:

• Penicillin treatment failures: When patients fail to respond to initial penicillin therapy, amoxicillin-clavulanate achieves higher eradication rates. 1
• Recurrent tonsillitis: Amoxicillin-clavulanate demonstrates superior efficacy in preventing recurrent infections compared to penicillin (89% vs 42% success rate at one year). 3
• Suspected beta-lactamase producing bacteria: These organisms can "shield" Group A streptococci by inactivating penicillin, present in over 75% of chronically infected tonsils. 4
• Carrier state with recurrent episodes: When differentiating true infections from viral illness in streptococcal carriers becomes difficult. 1

Dosing Regimens

Adult dosing:

• Standard dose: 500 mg amoxicillin/125 mg clavulanate three times daily for 10 days. 2
• Each dose should be taken with meals to reduce gastrointestinal upset. 5

Pediatric dosing:

• Standard dose: 45 mg/kg/day of amoxicillin component divided into 2-3 doses. 2
• High-dose regimen (for treatment failures or resistant organisms): 80-90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses. 2

Mechanism of Superiority in Treatment Failures

• Beta-lactamase inhibition: Clavulanate protects amoxicillin from degradation by beta-lactamase-producing bacteria (Staphylococcus aureus, Haemophilus species, Bacteroides species) that colonize infected tonsils. 4, 6
• Eradication rates: Amoxicillin-clavulanate achieves 100% eradication in penicillin failures versus 70% with repeat penicillin therapy. 3
• Despite penicillin's universal in vitro susceptibility, bacteriologic failure occurs in up to 20% of patients, with half experiencing clinical failure. 4

Clinical Efficacy Data

• In recurrent tonsillitis, amoxicillin-clavulanate for 10 days resulted in only 11% recurrence rate over one year compared to 58% with penicillin. 3
• Group A streptococci eradication occurred in 6 of 7 patients (86%) treated with amoxicillin-clavulanate. 6
• Five-day courses of amoxicillin-clavulanate show comparable clinical efficacy to 10-day penicillin courses (83% vs 77% long-term eradication). 7

Important Caveats

• Do not use when simple amoxicillin would suffice: If susceptibility testing shows no beta-lactamase production, amoxicillin-clavulanate should not be used due to broader spectrum and higher cost. 5
• Gastrointestinal side effects: More common than with penicillin; taking with food reduces this risk. 5, 6
• Complete the full course: Even if symptoms improve early, incomplete treatment increases resistance risk and decreases effectiveness. 5
• Not indicated for viral pharyngitis: Should only be used for proven or strongly suspected bacterial infections. 5

Reassessment Protocol

• If no improvement occurs within 48-72 hours of starting any antibiotic, reassess to confirm diagnosis and consider switching agents. 1
• When switching from penicillin to amoxicillin-clavulanate, the broader coverage addresses potential beta-lactamase producing organisms missed by initial therapy. 1