What is the recommended treatment for an adult with strep throat and no known allergies?

Treatment of Adult Strep Throat Without Allergies

For an adult with confirmed strep throat and no allergies, prescribe penicillin or amoxicillin for 10 days—this remains the gold standard due to proven efficacy, zero documented resistance, narrow spectrum, safety, and low cost. 1, 2

First-Line Antibiotic Regimen

Penicillin or amoxicillin is the drug of choice for all non-allergic patients with confirmed Group A Streptococcus pharyngitis. 1, 2, 3

• Amoxicillin is equally effective to penicillin and more palatable, making it the preferred oral option for most patients 4, 5
• The FDA approves amoxicillin for upper respiratory tract infections due to susceptible Streptococcus species 3
• No Group A Streptococcus resistance to penicillin has ever been documented anywhere in the world, making it uniquely reliable 2

Critical Treatment Duration

A full 10-day course is essential to achieve maximal pharyngeal eradication of Group A Streptococcus and prevent acute rheumatic fever. 1, 2, 6

• Shortening the course by even a few days results in appreciable increases in treatment failure rates 2, 6
• The primary goal is not just symptomatic improvement but prevention of acute rheumatic fever, which requires adequate bacterial eradication 2
• Therapy can be safely postponed up to 9 days after symptom onset and still prevent acute rheumatic fever 2

Expected Clinical Benefits

Antibiotics shorten the duration of sore throat by only 1 to 2 days, with modest benefit (number needed to treat = 6 after 3 days, 21 after 1 week). 1

• The main value of antibiotics is preventing complications: acute rheumatic fever, peritonsillar abscess, and further spread of Group A Streptococcus 1
• Little evidence supports prevention of acute glomerulonephritis 1

Essential Adjunctive Therapy

All patients should be offered analgesic therapy regardless of antibiotic use. 1, 2

• Acetaminophen or NSAIDs (such as ibuprofen) for moderate to severe symptoms or high fever 2
• Throat lozenges can help reduce pain 1
• Aspirin is acceptable in adults but must be avoided in children due to Reye syndrome risk 2
• Corticosteroids are not recommended 2

Confirming the Diagnosis First

Only treat with antibiotics if Group A Streptococcus is confirmed by rapid antigen detection test or throat culture. 1, 5

• Use the Centor criteria (fever history, tonsillar exudates, no cough, tender anterior cervical adenopathy) to determine who needs testing 1, 5
• Patients with fewer than 3 Centor criteria do not need testing 1
• More than 60% of adults with sore throat receive antibiotics despite most cases being viral—avoid this overuse 1

Common Pitfalls to Avoid

• Do not prescribe broad-spectrum antibiotics when narrow-spectrum penicillin/amoxicillin is appropriate—this unnecessarily selects for antibiotic-resistant flora 2
• Do not shorten the 10-day course despite clinical improvement, as this increases treatment failure and rheumatic fever risk 2, 6
• Do not treat without confirming streptococcal infection, as the majority of pharyngitis is viral 1, 5
• Do not perform routine post-treatment throat cultures for asymptomatic patients who have completed therapy 2, 6

Why Not Other Antibiotics?

Penicillin's narrow spectrum, proven efficacy, and zero resistance make it superior to alternatives in non-allergic patients. 2, 4, 5

• Cephalosporins are more expensive and broader spectrum without added benefit in non-allergic patients 2
• Macrolides have 5-8% resistance rates in the United States and lack data proving they prevent rheumatic fever 2, 6
• Clindamycin has broader spectrum and should be reserved for penicillin-allergic patients 2