By Philip R. Fischer, MD, DTM&H

Professor of Pediatrics, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN; Department of Pediatrics, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates

SYNOPSIS: In England, and likely in many other areas of the world, antibiotics still are given for longer than is necessary. Excessively long durations of antibiotic use do not help patients and risk leading to more resistant infections.

SOURCE: Palin V, Welfare W, Ashcroft AM, van Staa TP. Shorter and longer courses of antibiotics for common infections and the association with reductions of infection-related complications including hospital admissions. Clin Infect Dis 2021;Feb 24. doi 10.1093/cid/ciab159. [Online ahead of print].

Increasing resistance of bacteria to antimicrobials is a threat to global health, and growing resistance has been linked to overuse of antibiotics. In the United Kingdom, more than 80% of antibiotic prescriptions are given by primary care providers, and there is variability in prescribing habits. Some focused research studies have revealed that shorter courses of antibiotics are similar in effectiveness to longer courses, and Palin and colleagues used a national database to explore links between the duration of antibiotic treatment and complications of the inciting illness.

A population-based cohort study used a database from general practices in England that include diagnoses, medication prescriptions, and demographic information with longitudinal follow-up. The study population included patients who received a prescription for a systemic antibiotic from their general practitioner and who had a diagnosis of a urinary tract infection or a non-pneumonia respiratory tract infection. Attention was paid to infection-related complications prompting hospitalization within 30 days of the prescription.

More than 4 million consultations for acute infections were registered during the study period 59% upper respiratory infections, 25% lower respiratory infections, and 16% urinary tract infections. Overall, 62% of antibiotic prescriptions were for six to seven days. Amoxicillin was the most commonly prescribed antibiotic for respiratory tract infections. However, for those receiving medication for eight- to 15-day courses, penicillin and doxycycline were used most commonly. Trimethoprim was the antibiotic most commonly used for urinary tract infections.

Most infection-related hospitalizations occurred during the first week following initiation of the prescribed antibiotic, and 0.15% of patients had an infection-related hospitalization. Early hospitalizations during the treatment course, likely suggesting a more severe illness at the time of presentation, were most common when patients had more comorbidities or were given longer-course prescriptions. Hospitalizations after the first week of treatment were independent of the length of antibiotic treatment, suggesting that there was no increased risk with shorter-course treatment.

The authors concluded that longer courses of antibiotics did not improve outcomes and that shorter courses of antibiotics did not add significant risk. They suggested that the current trend of prescribing relatively longer courses of antibiotics for respiratory and urinary infections should be reversed.


There are historical precedents for using 10-day courses of penicillin for streptococcal pharyngitis based on the initial studies that were done (“if it works, why change it?”) and based on data suggesting a greater risk of rheumatic fever with shorter courses. In developed nations, routine 10-day courses of antibiotics became common for a variety of conditions. However, antibiotic course durations are decreasing.

Even a couple of decades ago, otitis media usually was treated with a 10-day course of antibiotics. Then, observation without antibiotic treatment (with antibiotics subsequently given only to those who did not improve during the initial days of self-recovery) was found to be safe and effective for children older than 1 year of age.1 Cephalosporins were found to be effective for streptococcal pharyngitis when given for “just” five days. Urinary tract infection treatment courses shifted from 10 to five to three days and, for adults, to single doses.

Palin and colleagues excluded patients with a diagnosis of pneumonia from their study. However, although physicians in many developed nations continue to treat pneumonia for 10 days, the World Health Organization has had good practical and scientific success in treating childhood pneumonia for just three to five days. Increasing data and recommendations from the United States also support shorter treatment courses for pneumonia.2

One of the beauties of Palin’s study is that it analyzed outcomes in two different periods of time — the first week after prescription of the antibiotic and the subsequent three weeks. As expected, early complications (hospital admissions) were more common in those who were sicker at presentation. However, a review of later complications showed that abbreviated antibiotic courses were not less effective than longer courses.

Thus, Palin’s good study reminds us that shorter antibiotic courses can be both safe and effective. Judicious antibiotic use should include not only limiting initiation of unnecessary antibiotics but also limiting the duration of treatment with necessary antibiotics.

Palin and colleagues have done other studies related to antibiotic overuse. They found that simply reducing antibiotic prescriptions might be dangerous.3 Decreased antibiotic prescription rates were associated with subsequent increases in infection-related hospitalizations.3 Appropriate antibiotics must be given, but not for too long. 


  1. Homme JH. Acute otitis media and group A streptococcal pharyngitis: A review for the general pediatric practitioner. Pediatr Ann 2019;48:e343-e348.
  2. Same RG, Amoah J, Hsu AJ, et al. The association of antibiotic duration with successful treatment of community-acquired pneumonia in children. J Pediatr Infect Dis Soc 2020;piaa0.55. doi 10.1093/jpids/piaa055
  3. van Bodegraven B, Palin V, Mistry C, et al. Infection-related complications after common infection in association with new antibiotic
    prescribing in primary care: Retrospective cohort study using linked electronic health records. BMJ Open 2021;11:e041218.