What antibiotics (Abx) are recommended for recurrent streptococcal infections after tonsillectomy?

Antibiotics for Recurrent Strep After Tonsillectomy

For patients experiencing recurrent streptococcal pharyngitis after tonsillectomy, clindamycin (20-30 mg/kg/day in 3 divided doses for 10 days) is the preferred antibiotic regimen, with amoxicillin-clavulanate as an effective alternative. 1

Understanding the Clinical Context

After tonsillectomy, recurrent positive strep tests may represent either true recurrent infections or chronic GAS carriage with intercurrent viral infections. 1 Up to 20% of asymptomatic school-age children may be GAS carriers during winter and spring, and these carriers can experience viral pharyngitis episodes that test positive for GAS. 1 Chronic carriers are unlikely to spread the organism to close contacts and are at very low risk for developing suppurative or nonsuppurative complications like acute rheumatic fever. 1

First-Line Antibiotic Regimens

For documented recurrent GAS pharyngitis post-tonsillectomy, the following regimens are recommended:

Clindamycin (Preferred)

• Children: 20-30 mg/kg/day in 3 equally divided doses (maximum 300 mg/dose) for 10 days 1
• Adults: 600 mg/day in 2-4 equally divided doses for 10 days 1
• This regimen achieves high rates of bacterial eradication and is more effective than penicillin in this specific circumstance 1, 2

Amoxicillin-Clavulanate (Alternative)

• Children: 40 mg amoxicillin/kg/day in 3 equally divided doses (maximum 2000 mg amoxicillin/day) for 10 days 1
• Adults: 500 mg twice daily for 10 days 1
• Note that two 250-mg tablets are not equivalent to one 500-mg tablet, as both contain 125 mg of clavulanate 1
• This combination is superior to penicillin alone because it overcomes beta-lactamase-producing bacteria that can shield GAS from penicillin 3, 4

Penicillin with Rifampin (Alternative)

• Penicillin V: 50 mg/kg/day in 4 doses for 10 days (maximum 2000 mg/day) 1
• Plus rifampin: 20 mg/kg/day in 1 dose for the last 4 days of treatment (maximum 600 mg/day) 1
• Rifampin is relatively contraindicated in pregnant women 1

Benzathine Penicillin G with Rifampin (For Compliance Concerns)

• Benzathine penicillin G: 600,000 U for <27 kg; 1,200,000 U for ≥27 kg (single IM dose) 1
• Plus rifampin: 20 mg/kg/day in 2 doses for 4 days (maximum 600 mg/day) 1
• This regimen is particularly useful when adherence to oral medications is questionable 1

Why Standard Penicillin Often Fails

Beta-lactamase-producing bacteria (BLPB) are recovered from over 75% of tonsils in patients with recurrent infection. 3 These organisms "shield" GAS by inactivating penicillin, leading to bacteriologic failure in up to 20% of penicillin-treated patients. 3 This explains why antibiotics that overcome beta-lactamase (clindamycin, amoxicillin-clavulanate) or add rifampin to penicillin are more effective in this population. 1, 3, 4

Macrolides: Use with Caution

Macrolides (erythromycin, azithromycin, clarithromycin) are not included in primary recommendations for recurrent streptococcal tonsillitis because there are insufficient data to support their efficacy in this specific circumstance. 1 Additionally, 26% of S. pyogenes isolates may be clarithromycin-nonsusceptible, with eradication rates as low as 14-19% for resistant strains. 5 Macrolides should only be considered for patients with anaphylactic penicillin allergy. 6

When NOT to Treat

Antimicrobial therapy is not indicated for the large majority of chronic streptococcal carriers. 1 However, treatment may be considered in special circumstances:

• During a community outbreak of acute rheumatic fever, acute poststreptococcal glomerulonephritis, or invasive GAS infection 1
• During an outbreak of GAS pharyngitis in a closed or partially closed community 1
• In patients with a family or personal history of acute rheumatic fever 1
• In families with excessive anxiety about GAS infections 1

Critical Pitfalls to Avoid

• Do not use short courses (<10 days) of antibiotics: Short courses are less effective for GAS eradication and should be avoided. 6, 7
• Do not perform routine follow-up cultures: For asymptomatic patients who have completed appropriate therapy, follow-up throat cultures are not recommended. 1, 6
• Do not use continuous antimicrobial prophylaxis: This is not recommended except to prevent recurrence of rheumatic fever in patients with a previous episode. 1
• Do not assume all positive tests represent active infection: Many post-tonsillectomy patients with positive GAS tests are carriers experiencing viral infections rather than true bacterial infections. 1, 6

Distinguishing Carriers from True Infection

Helpful clues to differentiate chronic carriage with viral infection from acute streptococcal pharyngitis include:

• Patient age and season (winter/spring has higher carrier rates) 1
• Presence of viral symptoms (cough, rhinorrhea, hoarseness suggest viral infection in a carrier) 1, 6
• Clinical response to previous antibiotic therapy 1
• Presence or absence of GAS in throat cultures during asymptomatic intervals 1