Treatment of Strep Throat
Penicillin or amoxicillin for 10 days is the first-line treatment for streptococcal pharyngitis in patients without penicillin allergy. 1
First-Line Antibiotic Therapy
The IDSA guideline provides strong, high-quality evidence that penicillin or amoxicillin should be prescribed for 10 days as the drugs of choice for treating group A streptococcal (GAS) pharyngitis 1. This recommendation is based on:
- Proven efficacy and safety with decades of clinical use
- Narrow spectrum of activity that minimizes disruption of normal flora and reduces antibiotic resistance
- No documented penicillin resistance in GAS strains
- Low cost compared to alternatives
- Established track record in preventing suppurative and non-suppurative complications
Practical Dosing Considerations
- Amoxicillin is often preferred over penicillin V in young children due to better palatability of the suspension 1
- Once-daily amoxicillin (50 mg/kg, maximum 1000 mg) for 10 days has been shown effective and may enhance adherence 1
- Intramuscular benzathine penicillin G is preferred for patients unlikely to complete a full 10-day oral course 1
Treatment for Penicillin-Allergic Patients
For patients with penicillin allergy, the treatment algorithm depends on the type of allergic reaction 1:
Non-Anaphylactic Penicillin Allergy
- First-generation cephalosporins (cephalexin or cefadroxil) for 10 days
- Narrow-spectrum cephalosporins are strongly preferred over broad-spectrum agents
- Up to 10% of penicillin-allergic patients may also be allergic to cephalosporins 1
Anaphylactic-Type Penicillin Allergy
Cephalosporins should NOT be used. Alternative options include 1:
- Clindamycin for 10 days (resistance ~1% in the United States)
- Clarithromycin for 10 days
- Azithromycin for 5 days (12 mg/kg/day, maximum 500 mg)
Critical Caveat on Macrolides
There is significant resistance to azithromycin and clarithromycin in some parts of the United States 2. Clindamycin is generally the preferred alternative for penicillin-allergic patients given its low resistance rate 1.
Duration of Therapy
Most oral antibiotics require the full 10-day course to achieve maximal pharyngeal eradication of GAS 1. While the FDA has approved 5-day courses of cefdinir, cefpodoxime, and azithromycin, the IDSA guideline notes that studies supporting shorter cephalosporin courses have methodological limitations and cannot be endorsed 1. The exception is azithromycin, which is approved for 5 days in penicillin-allergic patients.
Antibiotics to AVOID
The following should NOT be used for strep throat 1:
- Tetracyclines (high prevalence of resistant strains)
- Sulfonamides and trimethoprim-sulfamethoxazole (do not eradicate GAS)
- Older fluoroquinolones like ciprofloxacin (limited activity against GAS)
- Newer fluoroquinolones like levofloxacin and moxifloxacin (unnecessarily broad spectrum, expensive)
- Amoxicillin-clavulanate (not indicated as initial treatment; unnecessarily broad spectrum) 3
Symptomatic Management
Adjunctive therapy is often useful 1:
- NSAIDs are more effective than acetaminophen for fever and pain relief 4
- Medicated throat lozenges used every 2 hours are effective 4
- Corticosteroids are NOT recommended routinely—they provide only minimal symptom reduction 4
Expected Clinical Response
Patients typically achieve clinical response within 24-48 hours of starting antibiotic therapy 1. It's important to remember that streptococcal pharyngitis is usually a self-limited disease 1.
Follow-Up Considerations
- Routine post-treatment throat cultures or rapid tests are NOT recommended 1
- Re-evaluate patients with worsening symptoms after appropriate antibiotic initiation or symptoms lasting >5 days after treatment starts 2
- Do NOT test or treat asymptomatic household contacts routinely (strong recommendation) 1
Common Pitfalls to Avoid
- Prescribing broad-spectrum antibiotics when narrow-spectrum agents are appropriate—this drives antibiotic resistance
- Using shorter antibiotic courses (except azithromycin in allergic patients)—10 days is required for most agents
- Treating without microbiologic confirmation—clinical diagnosis alone is unreliable 5, 6
- Prescribing macrolides as first-line therapy—reserve for documented penicillin allergy 3
- Treating asymptomatic household contacts—this is not warranted and exposes them to unnecessary antibiotic risks 1