The commonly prescribed antibiotic for COVID-19, azithromycin, is no more effective than a placebo in preventing the viral disease among non-hospitalised patients, and may in fact increase their chance of hospitalisation, a study has found.
The research, published in the Journal of the American Medical Association, included 263 participants who all tested positive for SARS-CoV-2, the virus which causes COVID-19, within seven days before entering the study.
None of the participants were hospitalised at the time of enrolment.
The researchers at the University of California, San Francisco (UCSF) and Stanford University in the US randomly selected 171 participants to receive a single, 1.2 gramme oral dose of azithromycin and 92 received an identical placebo.
At day 14 of the study, 50 per cent of the participants remained symptom free in both groups.
By day 21, five of the participants who received azithromycin had been hospitalised with severe symptoms of COVID-19 and none of the placebo group had been hospitalised.
“Among outpatients with SARS-CoV-2 infection, treatment with a single dose of oral azithromycin compared with placebo did not result in a greater likelihood of being free of symptoms at day 14,” the authors wrote in the study.
The researchers concluded that treatment with a single dose of azithromycin compared to placebo did not result in greater likelihood of being symptom-free.
“These findings do not support the routine use of azithromycin for outpatient SARS-CoV-2 infection,” said study lead author Catherine E. Oldenburg, an assistant professor at UCSF.
“The hypothesis is that it has anti-inflammatory properties that may help prevent progression if treated early in the disease. We did not find this to be the case,” Oldenburg said.
Azithromycin, a broad-spectrum antibiotic, is widely prescribed as a treatment for COVID-19 around the world.
Most of the trials done so far with azithromycin have focused on hospitalised patients with pretty severe disease, the researchers said.
“Our paper is one of the first placebo-controlled studies showing no role for azithromycin in outpatients,” Oldenburg added.