Treatment of Recurrent Streptococcal Pharyngitis After Augmentin Failure
For this 38-year-old woman with recurrent strep pharyngitis two weeks after completing Augmentin, treat with clindamycin 600 mg daily (divided into 2-4 doses) for 10 days, as this provides superior eradication rates in treatment failure scenarios. 1
Understanding What's Happening
You're facing one of three scenarios:
- True treatment failure with persistent GAS infection 1, 2
- Chronic GAS carrier experiencing a concurrent viral infection 1, 3
- New GAS infection acquired from close contacts 1, 2
The key distinction: chronic carriers (up to 20% of adults during winter/spring) harbor GAS without active immunologic response and are at very low risk for complications like rheumatic fever. 1, 3 However, since she's symptomatic and tested positive, retreatment is warranted. 1, 2
Recommended Treatment Approach
First-Line Option: Clindamycin
Clindamycin 600 mg/day divided into 2-4 doses for 10 days is the preferred choice because:
- It achieves high pharyngeal eradication rates even in chronic carriers who failed penicillin-based therapy 1, 3
- It's not inactivated by beta-lactamase-producing organisms that may be co-colonizing the pharynx 1, 4
- Resistance rates remain only ~1% among GAS isolates in the United States 3
- The evidence quality is strong with high-quality data supporting its use 1, 3
Alternative Regimens (if clindamycin unavailable or not tolerated)
Penicillin V plus rifampin combination: 1
- Penicillin V 500 mg four times daily for 10 days
- Add rifampin 600 mg once daily for the final 4 days
- This combination addresses potential beta-lactamase protection 1
First-generation cephalosporin: 2, 3
- Cephalexin 500 mg twice daily for 10 days
- Provides superior bacteriologic cure rates compared to penicillin alone 5
Critical Clinical Pitfalls to Avoid
Don't repeat Augmentin. Since she already failed amoxicillin-clavulanate, repeating the same agent is unlikely to succeed. 1, 2 The guidelines specifically recommend switching to an alternative antimicrobial class for recurrent episodes. 1, 3
Don't assume she's just a carrier without treatment. While carriers don't typically need antibiotics, her symptomatic presentation with positive testing warrants retreatment with a more effective agent. 1, 3
Don't order routine post-treatment testing. After completing the 10-day clindamycin course, reculturing is only indicated if symptoms persist or recur—not routinely for asymptomatic patients. 1, 2
Why the Initial 5-Day Augmentin Course Was Problematic
The 5-day duration was inadequate. A full 10-day course is essential to achieve maximal pharyngeal eradication and prevent complications. 3 Additionally, beta-lactamase-producing co-colonizers (Staph aureus, H. influenzae, anaerobes) may have protected the streptococci from the amoxicillin component despite the clavulanate. 4, 6
When to Consider Testing Household Contacts
If she experiences multiple repeated episodes over subsequent months, consider testing and treating household members with positive cultures to prevent "ping-pong" transmission. 2, 3 However, this is not necessary for a single recurrence. 1
Special Circumstances Requiring Different Management
If she has penicillin allergy history:
- Immediate/anaphylactic reactions: Use clindamycin (avoid all beta-lactams including cephalosporins due to 10% cross-reactivity) 3
- Non-immediate reactions: First-generation cephalosporins are safe (only 0.1% cross-reactivity risk) 3
If symptoms persist after clindamycin, evaluate for suppurative complications like peritonsillar abscess requiring drainage. 2