What is the recommended treatment for adult strep (streptococcal) pharyngitis?

From the Guidelines

The recommended dose and duration of azithromycin for adult strep pharyngitis is 12 mg/kg once daily (max = 500 mg) for 5 days. This is based on the guidelines provided by the Infectious Diseases Society of America, as outlined in the 2012 update for the diagnosis and management of group A streptococcal pharyngitis 1.

Key Points to Consider

• The diagnosis of strep pharyngitis should be established through throat swab and testing for GAS pharyngitis by rapid antigen detection test (RADT) and/or culture, as clinical features alone do not reliably discriminate between GAS and viral pharyngitis 1.
• For patients with penicillin allergy, alternatives to azithromycin include amoxicillin, first-generation cephalosporins (if no history of anaphylaxis to penicillin), or other macrolides such as clarithromycin.
• Complete treatment is essential even if symptoms improve quickly, as this helps prevent complications like rheumatic fever and post-streptococcal glomerulonephritis.
• Patients should rest, maintain hydration, and may use acetaminophen or ibuprofen for pain and fever.

Treatment Considerations

• Antibiotics work by inhibiting bacterial cell wall synthesis or protein synthesis, preventing bacterial replication and allowing the immune system to clear the infection.
• Most patients begin feeling better within 24-48 hours of starting antibiotics, and they are no longer contagious after 24 hours of antibiotic therapy.
• The choice of antibiotic should be based on the patient's allergy history, the severity of the infection, and the potential for resistance.

Additional Recommendations

• Routine use of back-up throat cultures for those with a negative RADT is not necessary for adults in usual circumstances, due to the low incidence of GAS pharyngitis in adults and the low risk of subsequent acute rheumatic fever 1.
• Anti-streptococcal antibody titers are not recommended in the routine diagnosis of acute pharyngitis, as they reflect past but not current events 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. 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)

The recommended dose of azithromycin for adult strep pharyngitis is not explicitly stated in the provided drug labels, but for pediatric patients, the dose is 12 mg/kg once a day for 5 days. The recommended duration of azithromycin for adult strep pharyngitis is not explicitly stated in the provided drug labels, but for pediatric patients, the duration is 5 days. For adults, the dose and duration can be inferred to be 500 mg once daily for 3 days for other infections, but this is not explicitly stated for strep pharyngitis. Key points:

• Azithromycin is used as an alternative to first-line therapy in individuals who cannot use first-line therapy.
• The efficacy of azithromycin in the treatment of strep pharyngitis has been established in pediatric patients, but the dose and duration for adults are not explicitly stated.
• Susceptibility tests should be performed when patients are treated with azithromycin to ensure the causative organism is susceptible to the drug 2.

From the Research

Azithromycin Dose and Duration for Adult Strep Pharyngitis

• The recommended dose and duration of azithromycin for adult strep pharyngitis vary depending on the study, but a single 2-g dose of extended-release azithromycin or 500 mg once daily for 3 days are commonly cited options 3, 4.
• A study comparing a single 2-g dose of azithromycin extended-release with 3 days of azithromycin immediate-release (500 mg once daily) found similar bacteriological eradication rates and clinical cure rates between the two groups 3.
• Another study suggested that azithromycin administered at a dosage of 60 mg/kg in children or administered for 3 days at a dosage of 500 mg/day in adults is more effective than other treatment regimens in producing eradication and clinical cure of group A streptococcal tonsillopharyngitis 4.
• However, a study comparing 10 days of clarithromycin with 5 days of azithromycin found that the longer course of clarithromycin was more effective in eradicating group A streptococci from the throats of individuals with symptomatic pharyngitis 5.

Treatment Guidelines

• The American Family Physician recommends penicillin (10 days of oral therapy or one injection of intramuscular benzathine penicillin) as the treatment of choice for streptococcal pharyngitis due to its cost, narrow spectrum of activity, and effectiveness 6.
• Azithromycin is not mentioned as a first-line treatment option in this guideline, but it may be considered for patients with penicillin allergy or those who cannot tolerate penicillin.
• The choice of antibiotic and duration of treatment should be based on the individual patient's needs and medical history, as well as the severity of the infection.

Key Findings

• Azithromycin is an effective treatment option for adult strep pharyngitis, with a single 2-g dose or 500 mg once daily for 3 days being commonly recommended 3, 4.
• The duration of treatment may impact the effectiveness of azithromycin, with longer courses potentially being more effective in eradicating group A streptococci 5.
• Penicillin remains the first-line treatment option for streptococcal pharyngitis, but azithromycin may be considered for patients with penicillin allergy or those who cannot tolerate penicillin 6.