Antibiotic of Choice for Non-Exudative Acute Tonsillitis/Pharyngitis
For non-exudative acute tonsillitis/pharyngitis, antibiotics are generally not indicated, as the absence of exudate strongly suggests a viral etiology that does not require antimicrobial therapy. 1
Clinical Decision Framework
When NOT to Use Antibiotics
Patients presenting with clinical features strongly suggesting viral infection (cough, rhinorrhea, hoarseness, oral ulcers) should not receive antibiotics or diagnostic testing for Group A Streptococcus (GAS). 1 The absence of exudate is a key indicator pointing away from bacterial pharyngitis.
The modified Centor/McIsaac criteria should guide decision-making: Patients with 0-2 criteria (which typically includes those without exudate) should not receive antibiotics to relieve symptoms. 1 Non-exudative pharyngitis typically scores low on these criteria, making bacterial infection unlikely.
When Antibiotics May Be Considered
If diagnostic testing (rapid antigen detection test or throat culture) confirms GAS despite the absence of exudate—which is uncommon but possible—then antibiotic therapy is warranted. 1
First-Line Antibiotic Choice (If GAS Confirmed)
Penicillin V or amoxicillin remains the drug of choice for confirmed GAS pharyngitis, regardless of exudate presence, based on proven efficacy, narrow spectrum, safety, and low cost. 1
Dosing Regimens
Penicillin V: Children 250 mg twice or three times daily; adolescents/adults 250 mg three to four times daily or 500 mg twice daily for 10 days 1
Amoxicillin: 50 mg/kg once daily (maximum 1000 mg) for 10 days, often preferred in young children due to palatability and once-daily dosing 1
Benzathine penicillin G (intramuscular): 600,000 units for patients <27 kg or 1.2 million units for ≥27 kg as a single dose, preferred when adherence to oral therapy is uncertain 1
Alternatives for Penicillin-Allergic Patients
Non-Anaphylactic Allergy
First-generation cephalosporins (cephalexin 20 mg/kg per dose twice daily or cefadroxil 30 mg/kg once daily) for 10 days are the preferred alternatives for patients with non-immediate penicillin allergy. 1, 2
Immediate/Anaphylactic Allergy
Clindamycin 7 mg/kg per dose three times daily (maximum 300 mg/dose) for 10 days is the preferred choice for patients with immediate hypersensitivity to penicillin. 1, 2 Clindamycin has approximately 1% resistance among GAS isolates in the United States and demonstrates high efficacy even in chronic carriers. 2
Azithromycin 12 mg/kg once daily (maximum 500 mg) for 5 days is an acceptable alternative, though macrolide resistance rates are 5-8% in the United States. 1, 2 Azithromycin requires only 5 days due to its prolonged tissue half-life. 1, 3
Clarithromycin 7.5 mg/kg per dose twice daily (maximum 250 mg/dose) for 10 days is another macrolide option. 1, 2
Critical Treatment Duration
A full 10-day course is essential for all antibiotics except azithromycin to achieve maximal pharyngeal eradication of GAS and prevent acute rheumatic fever. 1, 2 Shortening the course increases treatment failure rates and complication risk. 2
Common Pitfalls to Avoid
Do not prescribe antibiotics empirically for non-exudative pharyngitis without diagnostic confirmation of GAS. 1 The vast majority of these cases are viral and do not benefit from antibiotics.
Do not use cephalosporins in patients with immediate/anaphylactic penicillin reactions due to 10% cross-reactivity risk. 1, 2
Do not use macrolides as first-line therapy when penicillin can be used. 1, 2 Reserve them for true penicillin-allergic patients.
Do not prescribe courses shorter than 10 days (except azithromycin's 5-day regimen). 1, 2 This leads to treatment failure and increased complication risk.