Antibiotics for Sore Throat

A Cochrane review [Abstract] 1 included 29 studies with a total of 15 337 cases of sore throat. The majority of studies were conducted in the 1950s. The age of participants ranged from younger than 1 year to older than 50 years, but most participants across all studies were adults. All studies recruited patients presenting with symptoms of sore throat, but few of them distinguished between bacterial and viral aetiology.

1. Symptoms
   • Antibiotics compared to placebo or no treatment reduced at day 3 sore throat symptoms (RR 0.70, 95% CI 0.60 to 0.80; 16 studies, n=3 730) and headache (RR 0.49, 95% CI 0.34 to 0.70; 4 studies, n=1 020), but not fever (RR 0.75, 95% CI 0.53 to 1.07; 8 studies, n=1 443). Antibiotics also reduced sore throat at 1 week (RR 0.50, 95% CI 0.34 to 0.75; 14 studies, n=3 083). The number needed to treat for an additional beneficial outcome (NNTB) to prevent 1 sore throat at day 3 was less than 6 and at week 1 it was 18.
2. Non-suppurative complications
   • There were too few cases of acute glomerulonephritis to determine whether there was a protective effect of antibiotics compared with placebo (Peto OR 0.07, 95% CI 0.00 to 1.32; 10 studies, n=5 147). Antibiotics reduced acute rheumatic fever within 2 months compared to the control group (Peto OR 0.36, 95% CI 0.26 to 0.50; 18 studies, n=12 249). The overall prevalence of acute rheumatic fever was very low, particularly in the later studies.
3. Suppurative complications
   • Antibiotics reduced the incidence of acute otitis media within 14 days (Peto OR 0.21, 95% CI 0.11 to 0.40; 10 studies, n=3 646) and quinsy (peritonsillar abscess) within 2 months (Peto OR 0.16, 95% CI 0.07 to 0.35; 8 studies, n=2 433) compared to those receiving placebo or no treatment, but not acute sinusitis within 14 days (Peto OR 0.46, 95% CI 0.10 to 2.05; 8 studies, n=2 387).
4. Subgroup analyses of symptom reduction
   • Analysis of results of throat swabs showed that antibiotics were more effective against symptoms at day 3 (RR 0.58, 95% CI 0.48 to 0.71; 11 studies, n=1 839) if the swabs were positive for Streptococcus, compared to RR 0.78 (95% CI 0.63 to 0.97; 6 studies, n=736) if negative. Similarly at week 1, RRs 0.29 (95% CI 0.12 to 0.70; 7 studies, n=1 117) for positive, and 0.73 (95% CI 0.50 to 1.07; 5 studies, n=541) for negative swabs.

Clinical comment: In some countries (e.g. Finland, France, USA) the decision of antibiotic treatment is usually based on the results of positive throat swab or quick test for Streptococcus, while in many other countries clinical diagnosis in considered adequate. Quick diagnosis of group A streptococci was not attempted in most trials, and the treatment was not confined to patients with positive results.

References

• Spinks A, Glasziou PP, Del Mar CB. Antibiotics for treatment of sore throat in children and adults. Cochrane Database Syst Rev 2021;(12):CD000023. [PubMed]