From the Guidelines
For patients with penicillin allergy, Cephalexin is a recommended alternative to penicillin for streptococcal infections, with a dosage of 20 mg/kg/dose twice daily (max = 500 mg/dose) for 10 days, as supported by the Infectious Diseases Society of America guidelines 1. When considering alternatives to penicillin for streptococcal infections, it is essential to take into account the patient's allergy status and the potential for resistance to certain antibiotics.
- The guidelines recommend Cephalexin, Cefadroxil, Clindamycin, Azithromycin, and Clarithromycin as alternatives to penicillin for patients with penicillin allergy 1.
- Cephalexin is a cephalosporin antibiotic that is effective against streptococcal infections and has a strong, high recommendation strength, as per the guidelines 1.
- The dosage of Cephalexin is 20 mg/kg/dose twice daily (max = 500 mg/dose) for 10 days, which is a well-established treatment regimen for streptococcal pharyngitis 1.
- It is crucial to note that patients should complete the full course of antibiotics, even if symptoms improve quickly, to ensure complete eradication of the infection and prevent complications like rheumatic fever or kidney inflammation.
- Local resistance patterns should also be considered when selecting an alternative antibiotic, as some regions have reported increasing resistance to certain antibiotics, such as macrolides 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 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. Azithromycin is often effective in the eradication of susceptible strains of Streptococcus pyogenes from the nasopharynx
Alternative to penicillin for streptococcal infections:
- Azithromycin can be used as an alternative to first-line therapy in individuals who cannot use first-line therapy for pharyngitis/tonsillitis caused by Streptococcus pyogenes 2.
- It is essential to perform susceptibility tests before treatment, as some strains may be resistant to azithromycin 2.
- Azithromycin is often effective in eradicating susceptible strains of Streptococcus pyogenes from the nasopharynx 2.
From the Research
Alternatives to Penicillin for Streptococcal Infections
- Macrolides, such as clarithromycin and azithromycin, are rational alternatives to erythromycin for streptococcal pharyngitis/tonsillitis in penicillin-allergic patients 3
- Azithromycin has been shown to be safe in patients allergic to penicillin and/or cephalosporin, with no reactions reported in a study of 48 patients 4
- Clarithromycin and azithromycin have better activity against certain gram-positive organisms, such as Haemophilus influenzae and Moraxella catarrhalis, making them better choices for the treatment of community-acquired pneumonia 5
Characteristics of Alternative Antibiotics
- Azithromycin has a prolonged tissue half-life, allowing for a shorter treatment duration of 5 days, compared to 10 days for penicillin, erythromycin, and clarithromycin 3
- Clarithromycin is recommended for twice-daily administration, while azithromycin can be administered once daily 3
- Macrolides, such as clarithromycin and azithromycin, have been shown to have better tolerability and more convenient dosing regimens, which can improve compliance 5
Considerations for Penicillin Allergy
- Many patients report allergies to penicillin, but clinically significant IgE-mediated or T lymphocyte-mediated penicillin hypersensitivity is uncommon (<5%) 6
- Patients with a low-risk history of penicillin allergy can be evaluated with a direct amoxicillin challenge, while moderate-risk patients can be evaluated with penicillin skin testing 6