From the Guidelines
For adults with strep pharyngitis, the recommended dose of amoxicillin is 50 mg/kg once daily (max = 1000 mg) or 25 mg/kg (max = 500 mg) twice daily for 10 days, while for children, the dosage is 50 mg/kg once daily (max = 1000 mg) or 25 mg/kg (max = 500 mg) twice daily for 10 days, as stated in the 2012 update by the Infectious Diseases Society of America 1.
Key Considerations
- Amoxicillin is the preferred first-line treatment due to its excellent activity against Group A Streptococcus, good absorption, narrow spectrum, and low cost.
- The once-daily dosing option can improve adherence, especially in adults.
- Completing the full 10-day course is crucial, even if symptoms improve earlier, to ensure eradication of the bacteria and prevent complications like rheumatic fever.
- For patients with a penicillin allergy, alternatives include cephalexin (if not severely allergic) or macrolides like azithromycin, as recommended by the American Heart Association 2.
Additional Recommendations
- Patients should stay hydrated and use pain relievers as needed.
- Symptom improvement can be expected within 48 hours of starting antibiotics.
- After 24 hours of antibiotic therapy, patients are generally no longer contagious.
Evidence Summary
The Infectious Diseases Society of America recommends amoxicillin as the first-line treatment for strep pharyngitis due to its efficacy, safety, and cost-effectiveness 1, 3. Other antibiotics, such as penicillin and cephalosporins, are also effective but may have different dosing schedules and costs. Macrolides and clindamycin can be used as alternatives in patients with penicillin allergies.
From the Research
Amoxicillin Dosage for Strep Pharyngitis
- The dosage of amoxicillin for strep pharyngitis is not explicitly stated in the provided studies, but the dosage can be inferred from the study 4 which states that amoxicillin was administered at a dose of 40-50 mg/kg/day.
- This dosage is consistent with the standard treatment guidelines for strep pharyngitis, which recommend a 10-day course of antibiotics 5, 6.
- The study 4 also compared the effectiveness of once-daily and multiple-daily amoxicillin treatment regimens and found that the once-daily regimen was as effective as the multiple-daily regimens in eradicating group A streptococcal infection.
- It is worth noting that the studies provided do not include a comprehensive review of all possible dosages of amoxicillin for strep pharyngitis, and the optimal dosage may depend on various factors such as patient age, weight, and severity of symptoms.
Comparison with Other Antibiotics
- The studies provided compare the effectiveness of amoxicillin with other antibiotics such as penicillin 5, 6, azithromycin 7, and clarithromycin 8.
- The study 7 found that higher dosages of azithromycin were more effective in treating group A streptococcal tonsillopharyngitis, while the study 8 found that clarithromycin was as effective as penicillin in treating streptococcal pharyngitis.
- The study 5 recommends penicillin as the treatment of choice for strep pharyngitis due to its cost, narrow spectrum of activity, and effectiveness, but notes that amoxicillin is equally effective and more palatable.