Treatment of Antibiotic-Resistant Streptococcal Infections

First-Line Treatment Options

The American Academy of Pediatrics and the Infectious Diseases Society of America recommend penicillin and amoxicillin as the drugs of choice for Group A Streptococcus (GAS) pharyngitis in non-allergic patients, as penicillin-resistant GAS has never been documented anywhere in the world 3
For patients with suspected treatment failure on penicillin, clindamycin is recommended due to its very low resistance rate (approximately 1%) 1, 2
Narrow-spectrum cephalosporins such as cefadroxil or cephalexin for 10 days are effective alternatives for patients with suspected treatment failure on penicillin 4, 3

For patients with penicillin/amoxicillin treatment failure, the first option is clindamycin, with a dosage of 300-450 mg orally three times daily for 10 days in adults and children >30kg, and 20 mg/kg/day divided in 3 doses for 10 days in children 1, 2, 5
The second option is narrow-spectrum cephalosporins, such as cefadroxil or cephalexin, for 10 days 4

Macrolide resistance (erythromycin, clarithromycin, azithromycin) among GAS isolates in the US is approximately 5-8%, which can result in treatment failures 1, 2
Tetracyclines should not be used due to high prevalence of resistant strains 4
Sulfonamides and trimethoprim-sulfamethoxazole are ineffective against GAS and should not be used 4

The standard treatment duration is 10 days for most antibiotics to achieve maximal pharyngeal eradication of GAS 1
Azithromycin is given for 5 days due to its prolonged tissue half-life 1, 5

Routine post-treatment testing is not recommended unless the patient is at high risk for acute rheumatic fever or has recurrence of symptoms 6