Quebec's science advisors do not recommend colchicine to treat COVID-19; risk too high, benefits not shown

Medical advisors at Quebec’s health institute say they consider it premature to recommend doctors prescribe the drug colchicine to treat people with COVID-19.

During a technical briefing on Thursday about the COLCORONA study that evaluated colchicine, scientists at the National Institute for Excellence in Health and Social Services (INESSS) confirmed the study's results were not statistically significant.

They explained that, for example, the "well-designed" study demonstrated that treating 1,000 people with colchicine for 30 days would reduce the number of hospitalizations by 45, which is 14 fewer than in the placebo group.

Given the significant number of side effects shown in the group that took colchicine compared to placebo - in particular, a risk of pulmonary embolism (blood clots), they deemed the risks to patients too high.

The INESSS health officials said the risk of blood clots, was of most concern to the experts who form their committee.

The recommendation is an interim decision and could be reevaluated once the Montreal-led study on colchicine is peer-reviewed and published or more information, including the results of confirmatory studies, come to light.

Doctors and scientists who are part of a program at the MUHC that works to improve the treatment of infections and reduce adverse effects went the same route last Thursday.

A memo sent to doctors by the Antimicrobial Stewardship Program at the McGill University Hospital Centre said in part that “because of the uncertain benefit” and “the need for follow-up for toxicity effects,” it does not recommend routine therapy of COVID-19 cases with colchicine at this time.

All the new guidelines come after a tumultuous week that started with Montreal Heart Institute (MHI) researcher Dr. Jean-Claude Tardif making bold claims in a press release about the effectiveness of the medication and ended with pushback after many scientists were eventually able to scrutinize the study’s data themselves.

The current INESSS guidelines uphold earlier warnings about the use of colchicine for this indication.

The College of Physicians, the Order of Pharmacists, and INESSS together advised the medical community to use great prudence if considering prescribing colchicine as a COVID treatment, shortly after the MHI press release emerged.

The anti-inflammatory medication has been used for decades to treat gout and is also prescribed to treat pericarditis, an inflammation of the sac around the heart - but has never been used in patients with COVID-19.

But as principal investigator of the multi-centre clinical trial, Dr. Tardif has stood by all his glowing comments about the study’s results in interviews with CTV news.

He said the analysis showed colchicine is an “effective drug to treat out-of-hospital patients,” and could help prevent hospitalizations and deaths.

Dr. Tardif also suggested doctors could start prescribing the drug right away.

But a few days later, just hours after the detailed study manuscript was released online for scientists to pre-review, many doctors reacted to Dr. Tardif’s claims with skepticism, concluding the results were not statistically significant.

That means it’s impossible to determine if the benefits shown are due to the effects of the medication or occurred by chance.

Among those pouring cold water on Tardif’s interpretation was the chief of infectious diseases at the Jewish General Hospital during a Sunday-evening appearance on the popular French-language Radio-Canada talk show ‘Tout le monde en parle.’

“When we start to analyze from a statistical standpoint, it’s a study that I would say is less flamboyant than what was presented initially,” said Dr. Karl Weiss, who is also the head of Quebec’s association of medical microbiologists.

“The results do not show in an extremely important way that there is a benefit to using colchicine,” he said.

Dr. Weiss pointed out that people who took colchicine “also had more secondary effects than the people in the other group, among others, pulmonary embolism,” which are blood clots.

He, like other doctors who have spoken with CTV News, thinks it would be best if the study was repeated.

He said while the idea to study the existing anti-inflammatory medication is a good one, the study didn’t show “beyond all doubt what we expect from a scientific study, that we should start using it in our practices tomorrow morning.”

Along with a statistically significant number of blood clots as a side effect, some people enrolled in the colchicine trial also had diarrhea.

The medicine can also be toxic and even deadly in high doses, especially for those who have kidney problems.

Colchicine can also interact with common medications, like certain antibiotics, and some blood pressure medications, according to Dr. Emily McDonald, a scientist at the Research Institute of the MUHC. 

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