What antibiotics are recommended for a sore throat suspected to be caused by a bacterial infection?

Antibiotics for Sore Throat

Penicillin V, administered twice or three times daily for 10 days, is the recommended first-line antibiotic when bacterial pharyngitis treatment is indicated, based on its proven efficacy, narrow spectrum, low cost, and lack of resistance. 1

When to Consider Antibiotics

Antibiotics should not be used in patients with less severe presentations of sore throat (0-2 Centor criteria) to relieve symptoms. 1, 2 The modest benefits observed in patients with 3-4 Centor criteria (symptom reduction of 1-2 days) must be weighed against side effects, impact on microbiota, increased antimicrobial resistance, medicalization, and costs. 1, 3

• Use clinical scoring systems (Centor, McIsaac, or FeverPAIN) to assess the likelihood of bacterial pharyngitis before prescribing antibiotics. 4
• For low-risk patients (< 3 points): antibiotics are not indicated. 4
• For moderate-risk patients (3 points): consider delayed prescription as an option. 4
• For high-risk patients (> 3 points): antibiotics can be initiated immediately. 4

First-Line Antibiotic Choice

Penicillin V remains the treatment of choice due to its sufficient antibacterial spectrum, lower cost, and lack of resistance development. 1 The standard regimen is twice or three times daily for 10 days. 1, 2

• Amoxicillin is an acceptable alternative, particularly in younger children due to better taste and availability as syrup or suspension. 1, 3 Clinical cure rates for amoxicillin (86%) and penicillin (92%) are comparable in children with acute streptococcal tonsillopharyngitis. 1

Second-Line Options

For patients with severe penicillin allergy:

• Cefalexin (cephalosporin) is the preferred second-line option, particularly in regions with high macrolide resistance rates. 1
• Clarithromycin (macrolide) can be used where severe penicillin allergy exists, though it should be reserved for this indication due to antimicrobial stewardship concerns. 1

Duration of Treatment

The 10-day treatment duration is recommended despite evidence suggesting shorter courses may be effective. 1 A systematic review comparing 5-day courses of penicillin with 10-day courses showed small clinical differences favoring 10 days of treatment. 1 Treatment for 7 days was superior to 3 days or placebo in resolving symptoms. 1

• Short-duration newer antibiotics (2-6 days) showed slightly better clinical outcomes with shorter fever duration (mean difference -0.30 days) and throat soreness (mean difference -0.50 days), but had more gastrointestinal side effects. 1
• There is insufficient evidence to recommend shorter treatment lengths at this time. 1

Comparative Efficacy of Antibiotics

Cephalosporins vs. Penicillin:

• Cephalosporins showed better bacterial cure rates (OR 1.47,95% CI 1.06-2.03) but similar overall clinical cure rates compared to penicillin. 1
• Clinical relapse was lower for cephalosporins (OR 0.55,95% CI 0.30-0.99; NNTB 50), but this benefit was only significant in adults. 5

Macrolides vs. Penicillin:

• No evidence of differing efficacy between azithromycin and comparator agents including penicillin. 1
• No significant differences in symptom resolution or clinical outcomes between macrolides and penicillin. 5
• Children experienced more adverse events with macrolides compared to penicillin (OR 2.33,95% CI 1.06-5.15). 5

Special Situations

For retreatment of patients with multiple repeated culture-positive episodes:

• Amoxicillin-clavulanate at 40 mg/kg/day in 3 divided doses for 10 days can be considered. 3

In children:

• Both penicillin V and amoxicillin are effective first-line options. 1, 3
• Amoxicillin may be preferred due to palatability and formulation advantages. 1, 3

Common Pitfalls to Avoid

• Do not use antibiotics to prevent complications like rheumatic fever in low-risk patients, as this is not a specific indication for antibiotic therapy. 1, 3
• Avoid broad-spectrum antibiotics like amoxicillin-clavulanate as first-line therapy, as they increase resistance and side effects without additional clinical benefit. 3
• Do not treat viral sore throats (most cases with 0-2 Centor criteria) with antibiotics. 3
• Rapid antigen testing is necessary to identify patients who will benefit from treatment, as only GABHS-positive patients show clinical benefit from penicillin V in the first few days. 6
• Prevention of suppurative complications is not a specific indication for antibiotic therapy in sore throat. 1

Symptomatic Treatment

Ibuprofen or paracetamol are recommended as first-line treatments for symptom relief in all patients with acute pharyngitis, regardless of whether antibiotics are prescribed. 1, 2 Ibuprofen shows slightly better efficacy for pain relief, particularly after 2 hours of administration. 2