In search of a coronavirus killer: Can existing drugs really turn the tide in the Covid-19 pandemic?

With confirmed cases approaching one million and no vaccine yet available, the Covid-19 virus has sparked worldwide panic — yet with the fear has come hope that existing drugs might hold a cure. Is it all just wishful thinking?

Four months after it originated in China’s Hubei province, the novel coronavirus has spread to at least 180 countries and claimed more than 38,000 lives. With no proven treatment in sight, drastic measures have been taken by governments to contain its spread — but the world can’t rely on ‘social distancing’ and ‘self-isolation’ forever.

Amid the anxiety, there has been no shortage of drugs touted by the media and medical professionals as potential ‘game changer’ antidotes to the viral infection. RT took a look at some of the most widely-proffered options.

Anti-malarial drugs (Trump’s choice)

Drugs usually used to treat malaria have been suggested as a potential “game changer” against the coronavirus infection by everyone from US President Donald Trump and the US Department of Health to Russian medical specialists. 

The high-profile promotions and panic-buying of the drugs by governments has already led to shortages for those who use them to treat other conditions, including lupus and rheumatoid arthritis. The drugs, which suppress the immune system, are seen as potentially helpful against Covid-19 because the virus over-stimulates immune response which can cause organ failure. Yet, drugs like hydroxychloroquine and chloroquine are unlikely to save the world from this rapidly-spreading viral infection since they appear to be ineffective against the virus itself.

One of the first studies promoting anti-malarial drugs as an effective treatment against coronavirus was led by French physician and microbiologist, Didier Raoult — but it has since been repeatedly criticized by other experts for “methodological flaws” and skewed data.

While Raoult cited instances of the drugs being effective against Covid-19 in China, they were apparently not particularly useful when used to treat patients in Italian hospitals, according to Dr. Giorgio Palu, one of the leading European experts in virology and former president of the European Society of Virology. “We just assume they can affect some viruses like SARS, yet they were not proved clinically,” he told RT.

Professor Sergey Netesov, who heads the Bio Nanotechnologies Laboratory at Russia’s Novosibirsk State University, also questioned the idea of using these medicines against coronavirus. “These drugs are not antiviral ones. Neither are they antibiotics,” he explained, adding that the one-celled organism that causes malaria is actually a parasite, so these drugs are anti-parasite medicines and should not normally be effective against viruses.

HIV drugs — a long shot

A combination of two drugs, lopinavir and ritonavir, that are used to treat HIV and sold under the brand name Kaletra, has also been widely considered as a viable option in the fight against coronavirus. It was listed as a potential treatment by reputable Dutch publishing and analytics company Elsevier, though its effectiveness was still described as “unclear.”

The theory was that this combination of drugs prevented the coronavirus from infecting new cells in a patient’s body by affecting a certain enzyme within the virus itself, in the same way it does with HIV. Yet, what appeared to be sound in theory turned out to be ineffective in practice.

A Chinese study published in the New England Journal of Medicine showed that “no benefit was observed with lopinavir–ritonavir treatment beyond standard care.” Its results were also supported by Palu, who said that Italian medics are abandoning this option of treatment for coronavirus patients. Netesov, meanwhile, said that the lopinavir–ritonavir option was never likely to be a success, since HIV is caused by retroviruses which are quite different to coronaviruses.

Professor George Lomonossoff, a microbiologist at the British John Innes Center, shared that view. “The [enzymes] are not identical between the two viruses so the efficacy is uncertain,” he told RT.

Ebola virus drugs?

A drug called remdesivir, originally developed to treat the Ebola virus, has been another widely discussed treatment option. Designated an ‘orphan drug’ (one which treats extremely rare conditions and is therefore commercially underdeveloped) by the FDA, remsedivir emerged as one of the “most promising” treatments in numerous Western media reports. In the US, the Pentagon even rushed to secure doses of the experimental drug for US troops who have contracted the virus.

The idea is that remdesivir gets into the viral RNA (ribonucleic acid) and halts viral replication, making it an ideal treatment — but that’s just the theory. Its practical efficiency is much less certain, experts say. “We still do not have clear positive results in coronavirus treatment,” Netesov said while Lomonosoff said it “needs to be tested” first. 

Rheumatoid arthritis

It seems counterintuitive at first to suggest drugs that suppress the immune response can help fight an infection, but like the immune-suppressing anti-malarial drugs discussed above, a rheumatoid arthritis drug called tocilizumab has found its way onto the list of potential Covid-19 game changers.

This drug was first approved for use against coronavirus by China. Then Italian doctors reported that it helps patients suffering from severe pneumonia caused by the virus. Tocilizumab prevents the severe lung inflammation that has been seen in coronavirus sufferers and Palu believes it could be particularly effective in the “pre-severe” phase of the illness.

Lomonosoff explained that the drug doesn’t exactly inhibit the virus itself, but relieves the inflammation caused by the infection. In other words, Tocilizumab can’t help halt the global pandemic, but it could help at least a portion of the patients infected with Covid-19.

Interferon-based drugs

Another option involves exactly the opposite approach to the one envisioned with hydroxychloroquine and tocilizumab. This method involves stimulating immune response with interferon-based drugs, which are used for treating a variety of diseases from multiple sclerosis to cancer. 

With the coronavirus, the hope was that interferon-based drugs could block protein synthesis in human cells and stop the virus from replication – just as happens normally as part of an initial immune response. Yet, as Netesov warns, such an approach could bring more harm than good. 

Interferons “inhibit protein synthesis regardless of whether it involves proteins of a virus or a host,” he explained, adding that such drugs could not be used for a long time as they cause severe adverse effects. Such effects could involve disruption of blood cell replication or even suicidal ideation.

Besides, the drugs appear to be only effective in the first five days after a person becomes infected, since a virus usually develops a natural resistance to interferons beyond that point, the Russian specialist said. Since the first symptoms of Covid-19 tend to appear no sooner than 12 days after one contracts the virus, these drugs are unlikely to be particularly useful.

Can repurposing existing drugs work?

Medical experts have been “working on the hypothesis that combinations of drugs, working in ways that are different from their clinically prescribed roles” may be effective against Covid-19 or help to manage its symptoms, according to Ken Mills, professor of experimental haematology at Queen’s University Belfast, which was recently awarded a grant to fund Covid-19 treatment research.

The hope is that experts might identify treatments that can either prevent the virus infection or “reduce or alleviate” its symptoms, meaning fewer patients will become high-risk and need intensive treatment, Mills told RT.

Mills and his colleagues have been focusing on anti-viral and anti-inflammatory combinations but are keeping an “open mind” about which treatments could prove most useful when “repurposed” against the novel coronavirus.

Still, while multiple potential treatment options have been rapidly circulating in the media, none of them yet appears to be the cure that the world is searching for. It seems that for now, the preventive measures of social distancing and self-quarantine are the most reliable methods to limit the spread — and the quickest-possible development of a vaccine specifically to treat Covid-19 remains the holy grail.

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