From the Guidelines
For patients with a penicillin allergy who need treatment for strep throat, the first-line alternative is azithromycin 12 mg/kg once daily (max = 500 mg) for 5 days, as recommended by the Infectious Diseases Society of America 1. When considering treatment options for strep throat in patients with a penicillin allergy, it's essential to prioritize alternatives that are effective and safe. The guidelines provide several options, including:
- Azithromycin, oral: 12 mg/kg once daily (max = 500 mg) for 5 days 1
- Clarithromycin, oral: 7.5 mg/kg/dose twice daily (max = 250 mg/dose) for 10 days 1
- Clindamycin, oral: 7 mg/kg/dose 3 times daily (max = 300 mg/dose) for 10 days 1
- Cephalexin, oral: 20 mg/kg/dose twice daily (max = 500 mg/dose) for 10 days, but this should be avoided in individuals with immediate-type hypersensitivity to penicillin 1 It's crucial to note that resistance to macrolides, such as azithromycin and clarithromycin, can vary geographically and temporally, and local resistance patterns may influence the specific recommendation 1. Completing the full course of antibiotics is vital to prevent complications like rheumatic fever, even if symptoms improve quickly. If symptoms don't improve within 48-72 hours, follow-up with a healthcare provider is necessary to assess the infection's response to the prescribed antibiotic or to investigate another condition that might be present.
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 Because some strains are resistant to azithromycin, susceptibility tests should be performed when patients are treated with azithromycin.
Strep treatment with penicillin allergy: Azithromycin can be used as an alternative to first-line therapy for the treatment of pharyngitis/tonsillitis caused by Streptococcus pyogenes in individuals who cannot use first-line therapy, such as those with a penicillin allergy 2.
- Key points:
- Azithromycin is often effective in eradicating susceptible strains of Streptococcus pyogenes.
- Susceptibility tests should be performed when patients are treated with azithromycin due to potential resistance.
- Clindamycin may also be considered as an alternative treatment option for strep infections, especially in cases of severe infections or when azithromycin is not suitable 3.
From the Research
Strep Treatment with Penicillin Allergy
- Patients with a penicillin allergy can be treated with alternative antibiotics, such as erythromycin and first-generation cephalosporins, for streptococcal pharyngitis 4.
- First-generation cephalosporins are recommended for patients with nonanaphylactic allergies to penicillin 5.
- Azithromycin and clarithromycin are also options, but there is significant resistance to these antibiotics in some parts of the United States 5.
- A study found that clarithromycin was as effective and well-tolerated as penicillin in the treatment of streptococcal pharyngitis 6.
- Azithromycin has been shown to be safe in patients allergic to penicillin and/or cephalosporin 7.
- A comparison of azithromycin and clarithromycin in the treatment of lower respiratory tract infections found that both antibiotics were effective and well-tolerated, but with some differences in dosage and treatment duration 8.
Alternative Treatment Options
- Erythromycin is an option for patients with penicillin allergy, but it may have a broader spectrum of activity and higher cost compared to penicillin 4.
- First-generation cephalosporins, such as cefazolin or cephalexin, are recommended for patients with nonanaphylactic allergies to penicillin 5.
- Azithromycin and clarithromycin are macrolide antibiotics that can be used as alternative treatments, but their use may be limited by resistance patterns in certain regions 5.
Considerations for Treatment
- The choice of antibiotic should be based on the patient's allergy history, the severity of the infection, and the potential for resistance 4, 5.
- Patients with a history of anaphylaxis to penicillin should be treated with caution and alternative antibiotics should be chosen 5.
- The treatment duration and dosage of the chosen antibiotic should be based on the specific infection and the patient's response to treatment 6, 8.