From the Guidelines
For patients with strep pharyngitis who are allergic to penicillin, the recommended treatment includes a first-generation cephalosporin, clindamycin, clarithromycin, or azithromycin for 10 days, with azithromycin being a convenient 5-day option, as stated in the 2012 update by the Infectious Diseases Society of America 1. When considering treatment options, it's crucial to assess the severity of the penicillin allergy.
- For those not anaphylactically sensitive to penicillin, a first-generation cephalosporin can be used.
- Clindamycin and clarithromycin are also viable options for 10 days.
- Azithromycin, given for 5 days, offers a shorter treatment course, which may improve adherence. Key considerations include:
- Ensuring the patient is not anaphylactically sensitive to penicillin if considering cephalosporins.
- Monitoring for potential side effects and resistance patterns.
- Completing the full antibiotic course to prevent complications such as rheumatic fever or post-streptococcal glomerulonephritis, as emphasized by the guideline 1. Additional measures such as symptomatic relief with salt water gargles, adequate hydration, and over-the-counter pain relievers can also be beneficial. Patients are generally considered non-contagious 24 hours after initiating antibiotic therapy, allowing for a return to work or school 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 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)
Treatment for strep pharyngitis when penicillin allergic:
- Azithromycin is an alternative to first-line therapy in individuals who cannot use first-line therapy.
- The recommended dosage of azithromycin for pharyngitis/tonsillitis is 12 mg/kg once a day for 5 days.
- Azithromycin has been shown to be clinically and microbiologically effective in the treatment of pharyngitis due to documented Group A β-hemolytic streptococci (GABHS or S. pyogenes) 2.
- Key points:
- Azithromycin is effective in eradicating susceptible strains of Streptococcus pyogenes from the nasopharynx.
- Susceptibility tests should be performed when patients are treated with azithromycin.
- Data establishing efficacy of azithromycin in subsequent prevention of rheumatic fever are not available 2.
From the Research
Treatment Options for Strep Pharyngitis in Penicillin-Allergic Patients
- For patients allergic to penicillin, alternative treatments are required, as penicillin is the primary drug of choice for strep pharyngitis 3.
- Erythromycin is generally effective but has drawbacks such as multiple daily doses, lengthy treatment periods, and high rates of gastrointestinal side effects 3.
- Newer macrolides like clarithromycin and azithromycin offer lower rates of gastrointestinal complaints and more convenient dosing, making them rational alternatives to erythromycin for penicillin-allergic patients 3.
- Clarithromycin is recommended for twice-daily administration, while azithromycin is recommended for once-daily administration 3.
- The recommended duration of azithromycin therapy is 5 days, compared to 10 days for penicillin, erythromycin, and clarithromycin 3.
Comparison of Macrolide Therapies
- A study comparing 10 days of clarithromycin therapy to 5 days of azithromycin therapy found that clarithromycin was more effective in eradicating group A streptococci (91% vs 82%, P=.012) 4.
- The difference in eradication rates may be due to the duration of therapy, but the statistically significant difference raises questions about shortened courses of macrolide therapy for strep pharyngitis 4.
Other Treatment Options
- First-generation cephalosporins are also an option for patients with penicillin allergy, although there is a theoretical risk of cross-antigenicity 5, 6.
- Amoxicillin is equally effective as penicillin and more palatable, but may not be suitable for patients with penicillin allergy 5.
- Clarithromycin has been shown to be as effective and well-tolerated as penicillin in the treatment of streptococcal pharyngitis, with higher bacteriologic cure rates (95% vs 87%, P = .009) 7.