Study finds common COVID-19 antibiotic isn’t more effective than placebo

An antibiotic commonly prescribed to treat COVID-19 has been found to be no more effective than a placebo.

Research from the University of California, San Francisco shows that azithromycin didn’t offer more effectiveness than a placebo to prevent COVID-19 symptoms among non-hospitalized patients. In fact, the study showed that despite widespread prescription of the antibiotic, it might actually increase patients’ chances of hospitalization.

The results were published last week in the Journal of the American Medical Association.

“These findings do not support the routine use of azithromycin for outpatient SARS-CoV-2 infection,” lead author Catherine E. Oldenburg, an assistant professor with the UCSF Proctor Foundation, said in a press release. COVID-19 is caused by the SARS-CoV-2 virus.

Azithromycin is widely prescribed to treat COVID-19 in the U.S. and worldwide.

“The hypothesis is that it has anti-inflammatory properties that may help prevent progression if treated early in the disease,” Oldenburg said. “We did not find this to be the case.”

A February study published on PubMed showed azithromycin use was linked to “a reduction in mortality and ventilation days in other viral infections.” But the study cautioned that data was “scarce and of low quality.”

The more recent UCSF study involved 263 participants who tested positive for SARS-CoV-2 within seven days before entering the study. At the time of enrollment, no patients were hospitalized. One hundred and seventy-one participants were randomly chosen to receive a single, 1.2 gram oral dose of azithromycin. Ninety-two got an identical placebo.

By day 14 of the study, 50% of the participants in each group stayed symptom-free. Day 21 saw five participants who received azithromycin in the hospital with severe COVID-19 symptoms. No one in the placebo group was hospitalized.

Researchers concluded that treatment with a single dose of azithromycin as opposed to placebo didn’t lead to a greater likelihood of being symptom-free.

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