Antibiotics for people with sore throats

Spinks A, Glasziou PP, Del Mar CB

Published Online:

September 7, 2011

Sore throats are infections caused by bacteria or viruses. People usually recover quickly (usually after three or four days), although some develop complications. A serious but rare complication is rheumatic fever, which affects the heart and joints. Antibiotics reduce bacterial infections but they can cause diarrhoea, rash and other adverse effects and communities build resistance to them.

This review of 27 trials with 12,835 cases of sore throat found that antibiotics shorten the illness by an average of about one day and can reduce the chance of rheumatic fever by more than two-thirds in communities where this complication is common.

Abstract (click to read)

Background:

Sore throat is a common reason for people to present for medical care. Although it remits spontaneously, primary care doctors commonly prescribe antibiotics for it.

Objectives:

To assess the benefits of antibiotics for sore throat for patients in primary care settings.

Search strategy:

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2011, Issue 2, which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (January 1966 to May week 1, 2011) and EMBASE (January 1990 to May 2011).

Selection criteria:

Randomised controlled trials (RCTs) or quasi-RCTs of antibiotics versus control assessing typical sore throat symptoms or complications.

Data collection and analysis:

Two review authors independently screened studies for inclusion and extracted data. We resolved differences in opinion by discussion. We contacted trial authors from three studies for additional information.

Main results:

We included 27 trials with 12,835 cases of sore throat.

1. Non-suppurative complications
The trend was antibiotics protecting against acute glomerulonephritis but there were too few cases to be sure. Several studies found antibiotics reduced acute rheumatic fever by more than two-thirds within one month (risk ratio (RR) 0.22; 95% confidence interval (CI) 0.02 to 2.08).

2. Suppurative complications
Antibiotics reduced the incidence of acute otitis media within 14 days (RR 0.30; 95% CI 0.15 to 0.58); acute sinusitis within 14 days (RR 0.48; 95% CI 0.08 to 2.76); and quinsy within two months (RR 0.15; 95% CI 0.05 to 0.47) compared to those taking placebo.

3. Symptoms
Throat soreness and fever were reduced by using antibiotics by about half. The greatest difference was seen at day three. The number needed to treat to benefit (NNTB) to prevent one sore throat at day three was less than six; at week one it was 21.

4. Subgroup analyses of symptom reduction
Antibiotics were more effective against symptoms at day three (RR 0.58; 95% CI 0.48 to 0.71) if throat swabs were positive for Streptococcus, compared to RR 0.78; 95% CI 0.63 to 0.97 if negative. Similarly at week one, RR 0.29; 95% CI 0.12 to 0.70 for positive, and 0.73; 95% CI 0.50 to 1.07 for negative Streptococcus swabs.

Authors' conclusions:

Antibiotics confer relative benefits in the treatment of sore throat. However, the absolute benefits are modest. Protecting sore throat sufferers against suppurative and non-suppurative complications in high-income countries requires treating many with antibiotics for one to benefit. This NNTB may be lower in low-income countries. Antibiotics shorten the duration of symptoms by about 16 hours overall.

This record should be cited as:

Spinks A, Glasziou PP, Del Mar CB. Antibiotics for sore throat. Cochrane Database of Systematic Reviews 2006, Issue 4. Art. No.: CD000023. DOI: 10.1002/14651858.CD000023.pub3

Assessed as up to date:

May 18, 2011

PEARLS - Practical Evidence About Real Life Situations (click to read)

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.

Authored by:

Brian R McAvoy

Cochrane Primary Health Care Field

Health topics:

Ear, nose, & throat > Pharynx > Tonsillitis (acute)/pharyngitis

Infectious disease > Respiratory infections > Pharyngitis/tonsillitis

Lungs & airways > Respiratory infections > Pharyngitis/tonsillitis

Cochrane Summaries

Independent high-quality evidence for health care decision making

Antibiotics for people with sore throats

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