What medications are used to treat pharyngitis?

Medications for Treating Pharyngitis

For pharyngitis, antibiotics are indicated only for bacterial causes, particularly Group A Streptococcal (GAS) infections, with penicillin or amoxicillin being the first-line treatments due to their proven efficacy in preventing complications such as rheumatic fever. 1, 2

Diagnosis Before Treatment

Before prescribing medications, proper diagnosis is essential:

• Use the Centor Criteria to assess likelihood of streptococcal pharyngitis:

  1. Tonsillar exudates
  2. Tender anterior cervical lymph nodes
  3. Lack of cough
  4. Fever 2

• Patients with 0-2 Centor criteria likely have viral pharyngitis and don't require antibiotics

• Patients with 3-4 criteria should be tested with rapid antigen detection test (RADT) and/or throat culture 2

Treatment Algorithm for Pharyngitis

1. Viral Pharyngitis (Most Common)

• First-line approach: Watchful waiting, symptom relief, and no antibiotics 1
• Supportive care:
  • Cold liquids or ice chips
  • Gargling with cold water
  • Acetaminophen or NSAIDs for pain/fever
  • Avoiding hot/spicy/hard foods 2

2. Bacterial Pharyngitis (GAS/Strep Throat)

First-line antibiotics:

• Penicillin V:
  • Children: 250 mg 2-3 times daily for 10 days
  • Adults: 500 mg 2-3 times daily for 10 days 2
• Amoxicillin:
  • 50 mg/kg once daily (maximum 1000 mg) OR
  • 25 mg/kg twice daily (maximum 500 mg per dose) for 10 days 2

Second-line antibiotics:

• For non-anaphylactic penicillin allergy:
  • Cephalexin for 10 days 1, 2
• For anaphylactic penicillin allergy:
  • Clindamycin: 300-450 mg orally three times daily for 10 days
  • Clarithromycin: For severe penicillin allergy 1, 2
  • Azithromycin: 12 mg/kg once daily (max 500 mg) for 5 days 2, 3

Important: Complete the full antibiotic course (10 days, except for azithromycin which is 5 days) to prevent complications such as acute rheumatic fever 2

Special Considerations

Chronic GAS Carriers

For chronic carriers requiring treatment (in specific situations only):

• Clindamycin: 20-30 mg/kg/day in 3 doses (max 300 mg/dose) for 10 days 1
• Penicillin with rifampin: Penicillin V 50 mg/kg/day in 4 doses for 10 days plus rifampin 20 mg/kg/day for last 4 days 1
• Amoxicillin-clavulanic acid: 40 mg/kg/day in 3 doses for 10 days 1

Return to School/Work

Patients should complete at least 24 hours of antibiotics before returning to school or work to reduce transmission risk 2

Efficacy and Side Effects

• Azithromycin shows clinical success rates of 94-98% for streptococcal pharyngitis, with common side effects including diarrhea (6%), vomiting (6%), and abdominal pain (3%) 3
• Penicillin has lower clinical success rates (74-84%) but remains first-line due to narrow spectrum and prevention of rheumatic fever 3

Common Pitfalls to Avoid

1. Treating viral pharyngitis with antibiotics: Most pharyngitis cases are viral and don't require antibiotics 1, 2

2. Not completing the full antibiotic course: This increases risk of complications like rheumatic fever 2

3. Unnecessary treatment of GAS carriers: Chronic carriers generally don't require treatment unless specific circumstances exist (family history of rheumatic fever, outbreaks, etc.) 1

4. Relying solely on clinical presentation: Clinical signs alone cannot reliably distinguish bacterial from viral pharyngitis; testing is needed for patients with high Centor scores 2

5. Routine tonsillectomy: Not recommended solely to reduce frequency of GAS pharyngitis 1

By following this evidence-based approach, clinicians can effectively manage pharyngitis while minimizing unnecessary antibiotic use and preventing complications.