From the Guidelines
Penicillin is the first-line antibiotic treatment for Group A Streptococcus (GAS) infections, with oral penicillin V (250-500 mg twice daily for 10 days) or amoxicillin (500 mg twice daily or 1000 mg once daily for 10 days) recommended for patients without penicillin allergy. For patients with penicillin allergy, alternatives include cephalexin, azithromycin, or clindamycin 1. The choice of antibiotic should be based on the patient's allergy history and the severity of the infection.
Key Considerations
- The full 10-day course of antibiotics must be completed, even if symptoms resolve earlier, to prevent complications like rheumatic fever 1.
- Penicillin remains effective against GAS with no documented resistance, working by inhibiting bacterial cell wall synthesis 1.
- Prompt treatment reduces symptom duration, prevents complications, and decreases transmission to others 1.
Antibiotic Options
- For patients without penicillin allergy:
- For patients with penicillin allergy:
- Cephalexin (20 mg/kg/dose twice daily for 10 days) 1
- Azithromycin (12 mg/kg once daily for 5 days) 1
- Clindamycin (7 mg/kg/dose three times daily for 10 days) 1 It is essential to note that the treatment guidelines may vary depending on the patient's age, weight, and medical history, and that the treatment should always be guided by the most recent and highest-quality evidence available 1.
From the FDA Drug Label
Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first-line therapy in individuals who cannot use first-line therapy Azithromycin is often effective in the eradication of susceptible strains of Streptococcus pyogenes from the nasopharynx In three double-blind controlled studies, conducted in the United States, azithromycin (12 mg/kg once a day for 5 days) was compared to penicillin V (250 mg three times a day for 10 days) in the treatment of pharyngitis due to documented Group A β-hemolytic streptococci (GABHS or S. pyogenes) Azithromycin was clinically and microbiologically statistically superior to penicillin at Day 14 and Day 30 with the following clinical success (i.e., cure and improvement) and bacteriologic efficacy rates (for the combined evaluable patient with documented GABHS)
Azithromycin is an effective antibiotic for the treatment of Group A strep infections, specifically Streptococcus pyogenes, in individuals who cannot use first-line therapy.
- The clinical success rate of azithromycin in treating pharyngitis/tonsillitis caused by Streptococcus pyogenes is high, with a cure rate of 95% at Day 14 and 77% at Day 30 2.
- Azithromycin is often effective in eradicating susceptible strains of Streptococcus pyogenes from the nasopharynx 2.
- However, it is essential to note that penicillin is the usual drug of choice in the treatment of Streptococcus pyogenes infection and the prophylaxis of rheumatic fever 2.
From the Research
Group A Strep Antibiotic Treatment Options
- The following antibiotics have been studied for the treatment of group A streptococcal pharyngitis:
- Penicillin V
- Amoxicillin/clavulanate
- Cefpodoxime
- Cephalosporins
- Macrolides (e.g. clarithromycin, azithromycin)
- Carbacephem
Efficacy of Different Antibiotics
- A study published in 2004 3 found that 5 days of clarithromycin or amoxicillin/clavulanate treatment had clinical efficacy comparable to 10 days of penicillin V treatment, but amoxicillin/clavulanate and penicillin V were bacteriologically more effective than clarithromycin.
- A study published in 1988 4 found that 10 days of phenoxymethylpenicillin or cefadroxil treatment was more effective than 5 days of phenoxymethylpenicillin treatment in preventing recurrences of group A streptococcal pharyngotonsillitis.
- A systematic review published in 2013 5 found that there was no difference in symptom resolution between cephalosporins and penicillin, but cephalosporins may be more effective in preventing clinical relapse.
- A study published in 1994 6 found that 10 days of cefpodoxime treatment was more effective than 10 days of penicillin V treatment in eradicating group A beta-hemolytic streptococci from the throat.
- A systematic review published in 2021 7 found that there was low-certainty evidence that carbacephem may be more effective than penicillin for symptom resolution in adults and children, but the evidence was insufficient to draw conclusions regarding other comparisons.
Adverse Events
- The studies found that adverse events were generally mild and similar across different antibiotic treatment groups, with gastrointestinal side effects being the most common 3, 6, 7.
- One study found that children experienced more adverse events with macrolides than with penicillin 5.
- Another study found that azithromycin was associated with more adverse events than amoxicillin in children 7.