Best Medicine for Strep Throat
Penicillin or amoxicillin is the best medicine for strep throat in patients without a penicillin allergy. 1, 2
Why Penicillin/Amoxicillin is First-Line
Penicillin remains the gold standard after four decades because no documented resistance exists anywhere in the world among Group A Streptococcus, ensuring 100% susceptibility and reliable bacterial eradication. 1, 2, 3 This zero-resistance profile is unmatched by any alternative antibiotic and makes penicillin uniquely effective. 2
The drug has proven efficacy in preventing acute rheumatic fever—the primary therapeutic goal—supported by decades of controlled studies. 1, 2 Its narrow antimicrobial spectrum minimizes selection pressure for resistant flora compared with broader agents, and it has an excellent safety profile with rare serious adverse events. 1, 2, 3
Amoxicillin is equally effective and often preferred over penicillin V, particularly in children, because of better palatability and more convenient twice-daily dosing (versus penicillin V's 2-3 times daily schedule). 1, 2, 4
Recommended Dosing
Adults: Amoxicillin 500 mg orally twice daily for 10 days, or penicillin V 500 mg orally 2-3 times daily for 10 days. 1, 2
Children: Amoxicillin 50 mg/kg once daily (maximum 1000 mg) OR 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days. 5, 2 Penicillin V 250 mg orally 2-3 times daily for 10 days is an alternative. 2
Intramuscular option when adherence is uncertain: Benzathine penicillin G 600,000 units IM (if <27 kg) or 1.2 million units IM (if ≥27 kg) as a single dose ensures compliance and produces the highest cure rates. 1, 2, 6
Critical Treatment Duration
A full 10-day course is mandatory to achieve maximal pharyngeal eradication and prevent acute rheumatic fever, even when symptoms resolve within 3-4 days. 1, 5, 2 Shortening the course by even a few days markedly increases treatment-failure rates and rheumatic-fever risk. 5, 2, 3
Alternatives for Penicillin Allergy
Non-Immediate (Delayed) Penicillin Allergy
First-generation cephalosporins are the preferred alternative, with cephalexin 500 mg twice daily for 10 days (adults) or 20 mg/kg twice daily for 10 days (children, maximum 500 mg/dose). 5, 2, 3 The cross-reactivity risk with delayed penicillin reactions is only 0.1%. 5
Immediate/Anaphylactic Penicillin Allergy
Clindamycin is the preferred choice at 300 mg three times daily for 10 days (adults) or 7 mg/kg three times daily for 10 days (children, maximum 300 mg/dose), with only ~1% resistance among U.S. Group A Streptococcus isolates. 5, 2, 3 Clindamycin demonstrates superior eradication even in chronic carriers and treatment failures. 5
Azithromycin 500 mg once daily for 5 days (adults) or 12 mg/kg once daily for 5 days (children, maximum 500 mg) is an acceptable alternative, but macrolide resistance ranges from 5-8% in the United States. 5, 2, 7 Azithromycin is the only antibiotic requiring just 5 days due to its prolonged tissue half-life. 5, 2
Common Pitfalls to Avoid
- Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to up to 10% cross-reactivity risk with all beta-lactams. 5, 2
- Do not prescribe courses shorter than 10 days (except azithromycin's 5-day regimen), as this dramatically increases treatment failure and rheumatic fever risk. 5, 2, 3
- Do not use trimethoprim-sulfamethoxazole (Bactrim) or tetracyclines—they fail to eradicate Group A Streptococcus and do not prevent rheumatic fever. 5
- Do not prescribe azithromycin as first-line therapy when penicillin can be used—reserve it only for true penicillin-allergic patients. 2
Adjunctive Symptomatic Treatment
Offer acetaminophen or NSAIDs (such as ibuprofen) for moderate to severe sore throat or fever. 5, 2, 3 Avoid aspirin in children due to Reye syndrome risk. 5, 2 Corticosteroids are not recommended as adjunctive therapy. 5, 8