(1) Since the 1940s, a large number of comparative randomised placebo-controlled trials have evaluated
antibiotic therapy for
pharyngitis, initially parenteral
benzathine benzylpenicillin, then oral
phenoxymethylpenicillin (
penicillin V). Our literature search identified a Cochrane meta-analysis of all these trials, with the exception of one published in 2003. (2) When group A betahemolytic streptococci (group A streptococci) are present in the throat,
antibiotic therapy accelerates symptom relief (particularly
fever and
pain) by a day or two. This has been shown with 7-day treatments but not with 3-day treatments. There is no convincing evidence that
antibiotics relieve symptoms in children. (3) According to the Cochrane meta-analysis, signs of progression to locoregional
suppuration were noted in 1% of patients receiving placebo, compared to 0.09% of patients receiving
antibiotics in the most recent trials (statistically significant difference). (4) Comparative trials done in the 1950s showed that
benzathine benzylpenicillin helped prevent
acute rheumatic fever, reducing the risk by about 75%. Since 1985 nearly 1000 patients with
pharyngitis have been given a placebo in clinical trials, and none have developed
acute rheumatic fever. (5) There is no firm evidence that
antibiotics reduce the risk of acute
glomerulonephritis. (6) The adverse effects associated with most
antibiotics are mild. This is especially true for
penicillin. However, there is a risk of rare but serious adverse effects:
anaphylaxis is estimated to occur in 5 per 10 000 patients treated with
injectable penicillin, while the risk associated with oral
penicillin used to treat
pharyngitis has not been quantified. Moreover,
antibiotics affect the bacterial ecology, encouraging resistance among some bacterial species other than group A streptococci. (7) A strategy based on the use of a clinical diagnostic score, followed by a rapid test if the score is intermediate, seems to be the best way of restricting
antibiotics to patients with
pharyngitis due to group A streptococci. (8) In patients with group A streptococcal
pharyngitis, a strategy of starting
antibiotics only after 48 hours of symptoms delays symptom control but seems to reduce the risk of relapse. According to a clinical trial in patients with
pharyngitis from all causes, advising patients to postpone
antibiotic therapy reduces
antibiotic use by about 85%, without increasing the risk of serious clinical complications. (9) In practice, immediate
antibiotic therapy is justified for patients with severe symptoms or signs of progression to locoregional
suppuration, and when the local incidence of
acute rheumatic fever is high. In other situations, whether or not group A streptococci are involved,
antibiotic therapy should be started only if symptoms do not begin to improve after 48 hours of symptomatic treatments.