What is the recommended treatment for an adult patient with streptococcal (strep) infection?

Treatment for Adult Streptococcal Pharyngitis

Confirm Diagnosis Before Prescribing Antibiotics

For adults with sore throat, use the modified Centor criteria to determine who needs testing: award one point each for fever by history, tonsillar exudates, tender anterior cervical adenopathy, and absence of cough. 1

• Patients with 0-1 Centor criteria should NOT be tested or treated with antibiotics 1
• Patients with 2 or more criteria should receive rapid antigen detection testing (RADT) 1
• Unlike children, adults with negative RADT do not require confirmatory throat culture 1
• Only treat patients with laboratory-confirmed Group A streptococcal infection 1

This algorithmic approach prevents unnecessary antibiotic prescriptions—currently 60% of adults with sore throat receive antibiotics despite only 10% having streptococcal infection 2. The Centor criteria provide a structured decision-making framework that is particularly useful for virtual visits 2.

First-Line Antibiotic Treatment

Prescribe penicillin V 500 mg orally twice daily for 10 days, or amoxicillin 500 mg orally twice daily for 10 days for patients without penicillin allergy. 1

Alternative first-line option:

• Benzathine penicillin G 1.2 million units intramuscularly as a single dose 1

Penicillin remains the gold standard due to its proven efficacy, narrow spectrum, safety profile, and low cost 1. The 10-day duration is essential to ensure complete eradication of Group A Streptococcus from the pharynx and prevent complications 1, 3.

Penicillin-Allergic Patients

For patients with nonanaphylactic penicillin allergy, prescribe a first-generation cephalosporin. 2

• Erythromycin is an alternative, but significant resistance exists to azithromycin and clarithromycin in some U.S. regions 2
• First-generation cephalosporins show better Group A Streptococcus eradication rates 4

Critical Timing Considerations

Antibiotic therapy can be safely initiated up to 9 days after symptom onset and still prevent acute rheumatic fever. 1

This extended window allows time for proper diagnostic confirmation without compromising prevention of serious complications.

Symptomatic Management

Offer acetaminophen, NSAIDs, or throat lozenges for moderate to severe symptoms. 1

• Do NOT prescribe corticosteroids for routine streptococcal pharyngitis treatment 1
• Antibiotics shorten symptom duration by only 1-2 days (number needed to treat = 6 at 3 days, 21 at 1 week) 1
• The primary benefit is prevention of complications: acute rheumatic fever, peritonsillar abscess, and limiting spread during outbreaks 1

When NOT to Treat

Do NOT treat chronic Group A Streptococcus carriers who have repeated viral infections with positive tests—they are at low risk for complications and transmission. 1

• Do not routinely perform post-treatment testing in asymptomatic patients 1
• Chronic colonization is common despite appropriate antibiotic therapy and does not require treatment 4

Red Flags Requiring Reevaluation

Reevaluate patients with worsening symptoms after appropriate antibiotic initiation or symptoms lasting 5 days after treatment starts. 1, 2

Consider these complications:

• Peritonsillar abscess 1
• Parapharyngeal abscess 1
• Lemierre syndrome (particularly in adolescents and young adults with severe pharyngitis) 1

Common Pitfalls to Avoid

• Do not rely on oral antibiotics in patients with severe illness, nausea, vomiting, or intestinal hypermotility—these patients may not absorb therapeutic amounts 3
• Complete the full 10-day course even if feeling better early—skipping doses increases bacterial resistance and treatment failure 3
• Contact physician immediately if watery and bloody stools develop, even up to 2 months after completing antibiotics 3