What is the recommended dose of amoxicillin (amoxicillin) for adults with streptococcal pharyngitis (strep throat)?

From the Guidelines

For adults with strep throat, the recommended dose of amoxicillin is 50 mg/kg once daily (max = 1000 mg) or 25 mg/kg twice daily (max = 500 mg) for 10 days. This dosage is based on the strongest and most recent evidence from the Infectious Diseases Society of America (IDSA) guidelines 1. The IDSA guidelines recommend amoxicillin as a first-line treatment for streptococcal pharyngitis in patients without penicillin allergy.

Key Considerations

• The dosage of amoxicillin should be taken for the full 10-day course to ensure complete eradication of the bacteria.
• Patients should be advised to take the medication with or without food, but taking it with food may help reduce stomach upset.
• It is essential to complete the entire course of antibiotics even if symptoms improve before the medication is finished, as stopping early can lead to recurrence or antibiotic resistance.
• Amoxicillin works by inhibiting bacterial cell wall synthesis, effectively killing the Streptococcus pyogenes bacteria that cause strep throat.
• If a patient has a penicillin allergy, alternative antibiotics like azithromycin or clindamycin would be recommended instead, as outlined in the IDSA guidelines 1.

Additional Recommendations

• Patients should stay hydrated and consider over-the-counter pain relievers like acetaminophen or ibuprofen to manage throat pain and fever while the antibiotic takes effect.
• The IDSA guidelines also recommend that physicians exclude the diagnosis of GAS pharyngitis to prevent inappropriate administration of antimicrobials to large numbers of patients with nonstreptococcal pharyngitis 1.

The most recent and highest quality study, which is the 2013 IDSA update 1, supports the use of amoxicillin as a first-line treatment for streptococcal pharyngitis, with a recommended dose of 50 mg/kg once daily (max = 1000 mg) or 25 mg/kg twice daily (max = 500 mg) for 10 days. This recommendation is based on strong, high-quality evidence and prioritizes the patient's morbidity, mortality, and quality of life.

From the FDA Drug Label

In Adults, 750 to 1750 mg/day in divided doses every 8 to 12 hours

• The recommended dose of amoxicillin for adults is 750 to 1750 mg/day in divided doses every 8 to 12 hours.
• The drug label does not specify a dose for streptococcal pharyngitis (strep throat) explicitly, but it does provide general dosing information for upper respiratory tract infections.
• Based on the available information, a conservative clinical decision would be to use the lower end of the recommended dose range, 750 mg/day, in divided doses every 8 to 12 hours, for the treatment of streptococcal pharyngitis in adults 2.

From the Research

Recommended Dose of Amoxicillin for Adults with Strep Throat

• The recommended dose of amoxicillin for adults with streptococcal pharyngitis is not explicitly stated in the provided studies, as they primarily focus on pediatric populations or do not specify adult dosages.
• However, based on the studies, it can be inferred that a once-daily dosing regimen of amoxicillin may be effective in treating streptococcal pharyngitis, as seen in studies 3, 4, 5.
• The American Heart Association has recommended once-daily amoxicillin dosing for the treatment of group A beta-hemolytic streptococcal pharyngitis, as mentioned in study 3.
• Study 5 used a dose of 750 mg of amoxicillin once daily for 10 days in children, but it is unclear if this dose would be applicable to adults.
• Further research would be needed to determine the optimal dose of amoxicillin for adults with streptococcal pharyngitis.

Comparison to Other Antibiotics

• Amoxicillin has been compared to other antibiotics, such as penicillin V, in the treatment of streptococcal pharyngitis, with similar effectiveness seen in studies 4, 5.
• Macrolides, such as azithromycin and clarithromycin, have also been used to treat streptococcal pharyngitis, particularly in patients allergic to penicillin, as mentioned in study 6.
• The choice of antibiotic and dosing regimen may depend on various factors, including patient allergies, compliance, and cost, as discussed in studies 3, 6, 7.