PEARLS 48, November 2007, written by Brian R McAvoy
(first published in New Zealand Doctor, 12 March 2008)

Clinical question
Should I prescribe antibiotics for patients with sore throats?

Bottom line
Antibiotics confer relative benefits in the treatment of sore throats, but their absolute benefits are modest. Compared to placebo, antibiotics reduce bacterial infections, such as acute otitis media and acute sinusitis.Throat soreness and fever are reduced by antibiotics by about one half.The median NNT*=5 to prevent one sore throat at day 3.The median NNT=23 to prevent one sore throat at day 7. Antibiotics shorten the duration of symptoms by about 16 hours overall. *NNT = number needed to treat to benefit one individual.

Caveat
Antibiotics can cause adverse effects, such as diarrhoea and rashes, and communities build resistance to them.

Context
Sore throats are infections caused by bacteria or viruses, affecting mostly children and young adults. Protecting individuals with sore throat against suppurative and non-suppurative complications in modern Western society can only be achieved by treating many with antibiotics, most of whom will derive no benefit. In emerging economies (eg, where rates of acute rheumatic fever are high), the number needed to treat may be much lower for antibiotics to be considered effective.

Cochrane Systematic Review
Del Mar CB et al. Antibiotics for sore throat. Cochrane Database of Systematic Reviews 2006, Issue 4. Article No. CD000023. DOI: 10.1002/14651858.CD000023.pub3. Note: This review contains 27 studies with 2835 participants.