What is the treatment for Streptococcus (Strep) pyogenes infection?

From the Guidelines

Strep pyogenes (Group A Streptococcus) infections are typically treated with antibiotics, with penicillin being the first-line treatment, as recommended by the most recent guidelines 1. For most uncomplicated infections, oral penicillin V (phenoxymethylpenicillin) at 250-500 mg 2-4 times daily for 10 days is recommended.

• The dosage may vary depending on the patient's age and weight, with children typically receiving 250 mg twice or three times a day, and adolescents and adults receiving 250 mg three or four times a day, or 500 mg twice a day 1.
• For patients with penicillin allergy, alternatives include erythromycin (500 mg four times daily for 10 days), azithromycin (500 mg on day 1, then 250 mg daily for 4 days), or clindamycin (300 mg three times daily for 10 days) 1.
• In severe cases requiring intravenous therapy, penicillin G (2-4 million units every 4-6 hours) is preferred, and for cases of necrotizing fasciitis, clindamycin and penicillin is the recommended treatment 1. It's crucial to complete the full course of antibiotics even if symptoms improve quickly to prevent complications like rheumatic fever or glomerulonephritis.
• Supportive care with adequate hydration, rest, and over-the-counter pain relievers like acetaminophen or ibuprofen can help manage symptoms such as fever and throat pain. Penicillin remains highly effective against Strep pyogenes because, unlike many other bacteria, this organism has not developed resistance to penicillin, making it a reliable treatment option that directly targets the bacterial cell wall synthesis.
• The choice of antibiotic should be based on the severity of the infection, the patient's age and weight, and any allergies or sensitivities to penicillin or other antibiotics.
• In cases of necrotizing fasciitis or streptococcal toxic shock syndrome, prompt surgical consultation and aggressive treatment with antibiotics and supportive care are essential to prevent morbidity and mortality 1.

From the FDA Drug Label

It is recommended that there be at least 10 days’ treatment for any infection caused by Streptococcus pyogenes to prevent the occurrence of acute rheumatic fever Pharyngitis/tonsillitis caused by Streptococcus pyogenes as an alternative to first-line therapy in individuals who cannot use first-line therapy. NOTE: Penicillin by the intramuscular route is the usual drug of choice in the treatment of Streptococcus pyogenes infection and the prophylaxis of rheumatic fever. The recommended treatment for Strep pyogenes is amoxicillin for at least 10 days to prevent the occurrence of acute rheumatic fever.

• First-line therapy: Penicillin by the intramuscular route is the usual drug of choice.
• Alternative therapy: Azithromycin can be used as an alternative to first-line therapy in individuals who cannot use first-line therapy 2 3 3.

From the Research

Treatment Options for Strep Pyogenes

• The primary treatment for Strep Pyogenes infections is antibiotics, with the goal of preventing acute rheumatic fever, suppurative complications, and transmission to close contacts 4.
• Penicillin and amoxicillin are recommended as first-line antibiotics, with a course of 10 days 4, 5.
• First-generation cephalosporins are recommended for patients with nonanaphylactic allergies to penicillin 5.
• Clindamycin has been shown to be effective in eradicating pharyngeal S. pyogenes carriage, particularly in asymptomatic individuals 6.
• Macrolides, such as azithromycin, may be used as an alternative, but resistance has been reported in some regions 4, 7, 8.

Antibiotic Resistance and Sensitivity

• Streptococcus pyogenes has remained susceptible to penicillin and other β-lactams, despite widespread use for 80 years 7.
• Resistance to macrolides has been identified in some geographic regions, with 19% of strains resistant in one study 8.
• Clindamycin resistance is less common, but has been reported, particularly in cutaneous samples 8.
• In vitro susceptibility testing is necessary in case of macrolide chemotherapy due to the reduced prevalence of macrolide-susceptible strains 8.

Treatment Challenges and Future Directions

• The failure of treatment for invasive infections with penicillin has been consistently reported, and strains with reduced susceptibility to β-lactams have emerged 7.
• Further understanding of the mechanisms contributing to antibiotic failure is necessary for improving treatment of high-risk GAS infections and surveillance for non-susceptible or resistant isolates 7.
• Adjunctive therapeutics and alternative treatment options, such as cefdinir and cefpodoxime proxetil, may offer improved outcomes and increased adherence to treatment regimens 4.