What is the drug of choice for a patient presenting with tonsillitis?

Drug of Choice for Tonsillitis

Penicillin V is the drug of choice for bacterial tonsillitis, with amoxicillin as an equally acceptable first-line alternative. 1, 2

Diagnostic Confirmation Required Before Treatment

• Never prescribe antibiotics without microbiological confirmation of Group A Streptococcus (GAS) through rapid antigen detection testing (RADT) and/or throat culture 2, 3
• Use the Centor/McIsaac criteria to guide testing: fever, tonsillar exudate, tender anterior cervical lymphadenopathy, and absence of cough 2, 3
• Patients with 0-2 Centor criteria should not receive antibiotics as viral etiology is most likely 2
• Patients with 3-4 Centor criteria warrant testing and consideration of antibiotics only if GAS-positive 2

First-Line Antibiotic Treatment

Penicillin V remains the standard of care despite historical concerns about failure rates, as it provides proven efficacy, safety, narrow spectrum activity, and low cost 4, 1:

• Children: 250 mg twice or three times daily for 10 days 1, 2
• Adolescents/Adults: 250 mg four times daily OR 500 mg twice daily for 10 days 1, 2

Amoxicillin is an equally acceptable first-line option with the advantage of once or twice daily dosing 1, 2:

• Dosing: 50 mg/kg once daily (maximum 1000 mg) OR 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 1, 2

The 10-day duration is critical to maximize bacterial eradication and prevent complications like rheumatic fever—shorter courses increase treatment failure risk 1, 2, 3

Treatment for Penicillin-Allergic Patients

Non-Anaphylactic Penicillin Allergy

First-generation cephalosporins are appropriate 1, 2, 3:

• Cephalexin: 20 mg/kg/dose twice daily (maximum 500 mg/dose) for 10 days 1
• Cefadroxil: 30 mg/kg once daily (maximum 1 g) for 10 days 1

Anaphylactic Penicillin Allergy

Clindamycin is the preferred alternative 1, 2, 3:

• Dosing: 7 mg/kg/dose three times daily (maximum 300 mg/dose) for 10 days 1

Macrolides are less preferred due to increasing GAS resistance 1, 5, 6:

• Azithromycin: 12 mg/kg once daily (maximum 500 mg) for 5 days 1
• Clarithromycin: 7.5 mg/kg/dose twice daily (maximum 250 mg/dose) for 10 days 1
• Erythromycin is generally effective but complicated by multiple daily doses and high rates of gastrointestinal side effects 5, 6

Management of Treatment Failures and Recurrent Tonsillitis

For patients with documented GAS tonsillitis recurring within 2 weeks of completing standard therapy 2, 3:

• Clindamycin: 20-30 mg/kg/day in 3 divided doses (maximum 300 mg/dose) for 10 days 2
• Amoxicillin-clavulanate: 40 mg/kg/day (amoxicillin component) in 3 divided doses for 10 days 2, 3

The rationale for these agents is their activity against beta-lactamase-producing bacteria that may "shield" GABHS from penicillin 7

Critical Pitfalls to Avoid

• Never initiate antibiotics without confirming GAS infection through testing—this leads to unnecessary antibiotic use and resistance 2, 3, 8
• Never use courses shorter than 10 days for standard penicillin or amoxicillin, as this increases treatment failure risk 1, 2, 3
• Do not perform follow-up throat cultures on asymptomatic patients who completed appropriate therapy 2, 3
• Do not use broad-spectrum antibiotics when narrow-spectrum penicillins are effective for confirmed GAS 2, 3
• Avoid treating low-risk patients (Centor score 0-2) with antibiotics for prevention of rheumatic fever or glomerulonephritis 8

Symptomatic Management

• NSAIDs (ibuprofen) or acetaminophen for pain and fever relief, regardless of whether antibiotics are prescribed 2, 3

When to Consider Tonsillectomy

Tonsillectomy is indicated only when episodes meet specific frequency thresholds 4, 2:

• ≥7 adequately treated episodes in the preceding year
• ≥5 episodes per year for 2 consecutive years
• ≥3 episodes per year for 3 consecutive years

Each episode must be documented with temperature ≥38.3°C, cervical adenopathy, tonsillar exudate, or positive GAS test 2, 9