Antibiotics Large study finds antibiotics aren't effective for most lower tract respiratory infections (Apr 2024, n=718) Antibiotics Not Associated with Shorter Duration or Reduced Severity of Acute Lower Respiratory Tract Infection

Michael Harrop

Active member
Jul 6, 2023

Use of antibiotics provided no measurable impact on the severity or duration of coughs even if a bacterial infection was present

patients have come to expect antibiotics for a cough, even if it doesn't help

The antibiotics prescribed in this study for lower tract infections were all appropriate, commonly used antibiotics to treat bacterial infections. But the researchers' analysis showed that of the 29% of people given an antibiotic during their initial medical visit, there was no effect on the duration or overall severity of cough compared to those who didn't receive an antibiotic

And they STILL largely ignore the effects of collateral damage of antibiotics



Antibiotic use remains common for the treatment of lower respiratory tract infections. The objective of this study was to evaluate the impact of antibiotic use on the duration and severity of acute lower respiratory tract infection (LRTI).


Adult patients presenting to US primary or urgent care sites with a chief complaint of cough and symptoms consistent with LRTI.

Main Measures​

Collected data included demographics, comorbidities, symptoms, and 48 viral and bacterial respiratory pathogens by PCR. Severity of signs/symptoms was reported for up to 28 days using diaries and text messages. Interpolation was used where data were missing.

Key Results​

Of 718 patients with baseline data, 29% had an antibiotic prescribed at baseline. The most common antibiotics were amoxicillin-clavulanate, azithromycin, doxycycline, and amoxicillin in 85% of patients. Provision of an antibiotic had no effect on the duration or overall severity of cough, including in patients with viral, bacterial, and mixed infections. Receipt of an antibiotic did reduce the likelihood of a follow-up visit (14.1% vs 8.2%, aOR 0.47, 95% CI 0.26–0.84), perhaps by removing the motivation of getting an antibiotic at a follow-up visit. However, they were also more likely to receive a systemic corticosteroid (31.9% vs 4.5%, p < 0.001) and were also more likely to receive an albuterol inhaler (22.7% vs 7.6%, p < 0.001). Patients believed that receiving an antibiotic would reduce the duration of their illness by nearly 4 days.


In this large prospective study in the US primary and urgent care setting, antibiotics had no measurable impact on the severity or duration of cough due to acute LRTI. Patients had unrealistic expectations regarding the duration of LRTI and the effect of antibiotics which should be the target of antibiotic stewardship efforts.
Format correct?
  1. Yes
I see this in practice all the time, often patients come in requesting antibiotics not knowing the collateral damage they can cause.
Would a study like this immediately change the way you prescribe antibiotics for this particular use case of lower tract respiratory infections? Or do you wait for some other guidelines to get updated?