Common Antibiotic – Azithromycin – No More Effective Than Placebo for COVID-19

Stained scanning electron micrograph of an apoptotic cell (green) heavily infected with SARS-COV-2 virus particles (purple), isolated from a patient sample. Image taken at the NIAID Integrated Research Facility (IRF) in Fort Detrick, Maryland. Credit: NIAID

A UC San Francisco study found that the antibiotic azithromycin was no more effective than a placebo in preventing symptoms of COVID-19 in non-hospitalized patients, and may increase their chances of hospitalization, despite widespread prescription of the antibiotic for the disease.

“These findings do not support the routine use of azithromycin for outpatient SARS-CoV-2 infection,” said lead author Catherine E. Oldenburg, ScD, MPH, an assistant professor at the UCSF Proctor Foundation. SARS-CoV-2 is the virus that causes COVID-19.

Azithromycin, a broad-spectrum antibiotic, is widely prescribed in the United States and around the world as a treatment for COVID-19. “The hypothesis is that it has anti-inflammatory properties that could help prevent progression if treated early in the disease,” Oldenburg said. “We did not think this was the case.”

The study, which was conducted in collaboration with Stanford University, appears July 16, 2021 in the Journal of the American Medical Association.

The study included 263 participants who all tested positive for SARS-CoV-2 within seven days of entering the study. No one had been hospitalized at the time of enrollment. In a randomized selection process, 171 participants received a single oral dose of 1.2 grams of azithromycin and 92 received an identical placebo.

On day 14 of the study, 50 percent of the participants remained symptom-free in both groups. On Day 21, five of the participants who received azithromycin were hospitalized with severe symptoms of COVID-19 and none of the placebo group was hospitalized.

The researchers concluded that treatment with a single dose of azithromycin compared to placebo did not increase the likelihood of being symptom-free.

“Most of the trials done with azithromycin to date have focused on hospitalized patients with quite severe disease,” Oldenburg said. “Our paper is one of the first placebo-controlled studies to show no role for azithromycin in outpatients.”

Reference: “Effect of oral azithromycin versus placebo on COVID-19 symptoms in outpatients with SARS-CoV-2 infection A randomized clinical trial” by Catherine E. Oldenburg, ScD, MPH; Benjamin A. Pinsky, MD, PhD; Jessica Brogdon, MPH, TM; Cindi Chen, MS1; Kevin Ruder, B.S.; Lina Zhong, BS; Fanice Nyatigo, B.S.; Catherine A. Cook, MPH; Armin Hinterwirth, PhD; Elodie Lebas, RN; Travis Redd, MD, MPH; Travis C. Porco, PhD, MPH; Thomas M. Lietman, MD; Benjamin F. Arnold, PhD, MPH and Thuy Doan, MD, PhD, Jul 16, 2021, JAMA.
DOI: 10.1001 / jama.2021.11517

Co-authors included Jessica Brogdon, MPH&TM; Cindi Chen, MS; Kevin Ruder; Lina Zhong; Fanice Nyatigo; Catherine A. Cook, MPH; Armin Hinterwirth, PhD; Elodie Lebas, RN; Travis Redd, MD, MPH; Travis C. Porco, PhD, MPH; Thomas M. Lietman, MD; and Benjamin F. Arnold, PhD, MPH, all of UCSF; senior researcher Thuy Doan, MD, PhD, at the UCSF Proctor Foundation, and Benjamin A. Pinsky, MD, PhD, from Stanford University.

The process was supported by the Bill and Melinda Gates Foundation (INV-017026). Azithromycin and matching placebo were donated by Pfizer, Inc. (New York, N.Y.). Thuy Doan was supported in part by a Research to Prevent Blindness Career Development Award. The authors had no conflicts of interest.