MONTREAL (AFP) - A major clinical trial shows that an inflammatory drug called colchicine is effective in treating Covid-19 and reduces the risk of complications from the disease, doctors in Canada said.

The results of the study are a "major scientific discovery" and make colchicine - a medicine used to treat gout - "the world's first oral drug that could be used to treat non-hospitalised patients with Covid-19," the Montreal Heart Institute said in a statement late on Friday (Jan 22).

The study results show that colchicine reduced by 21 per cent the risk of death or hospitalisations in patients with Covid-19 compared to placebo, the institute said.

The study was carried out in Canada, the US, Europe and South America among a population of 4,488 patients.

In 4,159 of these patients, in whom the diagnosis of Covid-19 was proven by a naso-pharyngeal PCR test, use of colchicine reduced hospitalisations by 25 per cent, the need for mechanical ventilation by 50 per cent, and deaths by 44 per cent, the study concluded.

Colchicine is effective in preventing dangerous inflammatory syndromes called "cytokine storms" and reducing complications associated with Covid-19, said Dr Jean-Claude Tardif, director of the MHI Research Centre and principal investigator in this study.

"We are pleased to offer the first oral medication in the world whose use could have a significant impact on public health and potentially prevent Covid-19 complications for millions of patients," Tardif said.

The study was conducted among Covid-19 patients not hospitalised at the time of enrollment in the trial, and with at least one risk factor for Covid-19 complications.

"This is the world's largest study testing an orally administered drug in non-hospitalised patients with Covid-19," the heart institute said.