As the majority of the world remains in stasis due to the continuing COVID-19 pandemic, many governments are turning their attention to a long-term cure. Lockdown measures seem to be effective for many countries, but as the crisis continues, quarantine will have dire consequences for many industries and the economy at large. So far, the months-long battle against COVID-19 has involved the exploration of many therapeutic pathways. Many physicians have found that hydroxychloroquine (informally known as an antimalarial) combined with azithromycin is showing encouraging results as a potential treatment for COVID-19. But does the science back it up? Are antimalarials effective at treating SARS-CoV-2?
Hydroxychloroquine In The Treatment of COVID-19
Hydroxychloroquine and azithromycin (HCQ-AZ) have been the talk and focus of much of the medical world as the search for COVID-19 treatment continues. The drug chloroquine has been used to treat malaria since the 1940s. The modern interpretation – and less-toxic – hydroxychloroquine is a synthetic form of quinine, found in the bark of the Cinchona plant. However, if it proves to be effective against COVID-19, it will not be by the same mechanism that makes it a useful antimalarial. Malaria is not the result of a virus, but a parasite; hydroxychloroquine disrupts the parasite’s feeding by making the host’s haemoglobin toxic. The drug might have a very different effect against the COVID-19 virus, possibly blocking its ability to enter cells.
Hydroxychloroquine is also out of patent, making it cheap and readily available. Six million treatment units are available to the German government alone. If they are proven to be effective and safe, mass treatment could begin in relatively short order. But why are these drugs in particular potentially so potent in the face of this devastating virus?
The Mechanism Behind Antimalarials
Essentially, it’s thought that antimalarials will stifle the virus’ ability to replicate. Viruses need acidity in the cells, but drugs like HCQ-AZ alkalise them instead. They do this by raising the pH level of endosomes, vesicles that the virus invades to gain entry to the cell. The base acidic pH of these endosomes helps the virus’ replication process.
Nabil Seidah and his team studied the antiviral effects of hydroxychloroquine in 2005, finding some evidence that it could be an inhibitor of SARS infection, which saw a global outbreak in the early 2000s. However, COVID-19 is a different prospect altogether, and it will likely involve a combination of drugs to treat effectively. However, like many other elements of this crisis, there is conflicting information about whether use of this drug will be effective.
What Is The Global Interpretation Of This Approach?
Could hydroxychloroquine be dangerous if used incorrectly in SARS-CoV-2 patients? This is the key question scientists are currently trying to answer. Unfortunately for patients, and for the world at large, regulators are divided on how effective and safe antimalarials are for COVID-19 sufferers. Earlier in April, America’s FDA (Food and Drug Administration) approved the use of hydroxychloroquine and chloroquine to treat COVID-19, citing no ‘adequate, available and approved’ alternative. However, both the EU and WHO (World Health Organisation) have criticised the move, stating that it comes too early, with no clear-cut scientific evidence supporting it.
What Do The Clinical Trials Reveal?
Some early studies have been conducted. One trial found significant improvement in patients infected with COVID-19 when treated with chloroquine and HCQ. One review found that ‘the HCQ-AZ combination, when started immediately after diagnosis, is a safe and efficient treatment for COVID-19, with a mortality rate of 0.5%, in elderly patients. It avoids worsening and clears virus persistence and contagiosity in most cases’. Another trial, conducted on a test group of 80 people, found that, with combined HCQ-AZ treatment, ‘all patients improved clinically except one 86-year-old patient who died, and one 74-year-old patient still in intensive care’.
The Case Against Antimalarials
Not all trials have been so resoundingly positive. It’s a fact that antimalarials can lead to heart issues, heightening chances of cardiac arrest. Many countries have issued warnings against prescribing hydroxychloroquine as a COVID-19 treatment due to these risks. Recently, the FDA warned doctors not to prescribe antimalarials outside of clinical trials or hospital settings. Canada followed suit soon after. A clinical trial investigating the efficacy of chloroquine and azithromycin combination therapy for COVID-19 in Brazil was also recently halted due to a spike in patient deaths.
New York governor Andrew Cuomo, a high-profile figure in the United States’ battle against rocketing infection rates, claimed recently that a review of medical records at the State of New York University at Albany indicated that the drug ‘didn’t really have much of an effect on the recovery rate’. This all adds to the confusing evidence and hype surrounding the potential treatment, creating frustration for patients, doctors and governments alike.
In conclusion, it seems that antimalarials are still too unstable to be prescribed en masse, with more clinical trials and positive evidence needed. The trials conducted so far have been encouraging, but the control group has been too small. The anecdotal evidence from doctors on the frontlines seems to also be optimistic about the potential treatment prospects of these drugs, but again, larger studies are key.
If one thing is clear, it’s that COVID-19 has left us reeling, and that everyone wants an effective remedy as quickly as possible. However, as we rapidly search for a treatment option, we have to make sure that the disease remains worse than the cure.