Tropical drug to be tested on critically ill patients here
IRISH Covid patients being treated in intensive care are to start receiving the drug ivermectin as part of an international clinical trial.
Ivermectin is an anti-parasitic drug that has been controversially promoted by some as a cure for the disease.
In 2015, Donegal scientist Professor William Campbell shared the Nobel Prize in Physiology or Medicine for his role in the discovery of ivermectin.
Launched in the 1980s as a drug against parasites, it was crucial in treating river blindness in many tropical countries.
Ivermectin is used in various animal medicines including ones for roundworms, mites and lice in sheep and cows.
Interest in ivermectin for Covid-19 was sparked by an Australian study in April last year that showed it killed SARS-CoV-2 in a test tube.
Some patients in Irish hospitals have received it as a treatment. Since it is an approved drug, it is at the discretion of clinicians to decide if an individual patient will benefit from it.
“Its use has crept into practice without a huge amount of evidence to support it,” said Professor Alistair Nichol, intensive care doctor at St Vincent’s University Hospital, Dublin. “There have been some clinical trials, but they haven’t been of the highest quality.”
A new international trial plans to answer, once and for all, if ivermectin is beneficial to Covid-19 patients.
Prof Nichol leads the Irish contribution to the trial, which is expected to start within weeks after it receives approval. Five Irish hospitals are likely to participate.
Irish patients will receive either a four-day course of ivermectin, or no ivermectin. The outcome of these two groups of patients will then be compared. The same study will be run in France, Pakistan, Nepal, the Netherlands, the US and Canada.
Having so many patients, from different medical centres, in different countries, should help answer definitively if the drug is beneficial.
“There has been a huge amount of media interest [in ivermectin],” said Prof Nichol. “There have been campaigns to put it in [treatment] guidelines, even though there is little evidence to support it.”
The US Food and Drug Administration does not recommend its use to treat Covid.
“There have been lots of media stories where people received ivermectin and said it was a miracle cure,” Prof Nichol added. “But there is not a whole load of hard evidence to back up its efficacy, or safety.”
Some previous studies compared Covid-19 patients who received ivermectin with those who received the malaria drug hydroxychloroquine.
Prof Nichol said hydroxychloroquine — promoted by former US president Donald Trump as a cure — is probably harmful to Covid-19 patients.
“It possibly made ivermectin look good,” he said.
Prof Nichol is approaching ivermectin as a Covid treatment with a dose of scepticism, but he said that the results from a large trial are necessary.
“We need to provide an answer for clinicians,” he explained. “Because clinicians are using it, and will continue to use it. We will find out if that is a good idea, or if it is not.”
The ivermectin study is part of a larger international trial (Remap-Cap) that involves thousands of patients.
This was set up to look at treatments for pneumonia, before Covid, in the expectation that the next pandemic would involve a respiratory virus that would trigger a flood of patients with pneumonia.
This trial recently reported that Covid-19 patients benefit from receiving either of two antibody therapies — tocilizumab and sarilumab — which block a compound in our body that promotes inflammation.
It also contributed to advice from the World Health Organisation in September last year that steroids could be used to treat severely ill Covid-19 patients.
The US’s drug regulator expressed concern last April that people might self-medicate by taking ivermectin products intended for animals, which it said could cause serious harm. “People should not take any form of ivermectin unless it has been prescribed to them by a licensed health care provider,” it warned.
One unknown is what dose might be needed to kill SARSCoV-2 in a patient. The test tube study in Australia used notably high doses.
“There is some basic research that suggests ivermectin may be an anti-viral, but the doses needed to achieve that was rarely achieved in humans,” said Prof Nichol.
The dose given to patients with roundworm or river blindness is different for different patients. Like all drugs, ivermectin has side-effects, and should not be taken unless prescribed by a medical professional.