Antibiotics for acute group A streptococcal pharyngitis.
(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.
D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005921:Glomerulonephritis / Q000517:prevention & control; D006801:Humans; D010612:Pharyngitis / Q000188:drug therapy* / Q000382:microbiology; D013290:Streptococcal Infections / Q000175:diagnosis / Q000188:drug therapy*; D013297:Streptococcus pyogenes / Q000302:isolation & purification; D013492:Suppuration / Q000209:etiology; D013997:Time Factors; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents