Donald Trump is touting an anti-malaria drug as a possible treatment for COVID-19, but it’s not yet clear how effective
A number of other existing drugs
are being tested for their effectiveness against coronavirus. If any are found to be successful, they might be able to
be distributed quickly due to existing stockpiles.
The SMC asked experts to comment on whether any of these treatments are showing promise.
Dr Christopher Gale, Senior Lecturer, Department of Psychological Medicine, University of Otago, comments:
“There are a fair number of cures being mentioned in social media and by various public figures for COVID-19. This is
normal human behaviour, people will try to do whatever they can to stay well and be able to care for their families and
friends. However, there is very little data behind this.
“There have been case reports from China and Italy of people in intensive care who have had various antiviral and
antibiotic medications, but no clear indication that any of these helped.
“What is happening is that various antiviral medications are being tested rapidly in the severe cases. It will not take
much time (or participants in the trials) to see if such a medication works or does not. Some things will be shown to
work, some will not. At that point the health system will be able to offer with confidence treatments for COVID. The
regulations and ethical approval for such trials is being facilitated by many governments.
“At present, however, we have no data. There is no point in seeking this medication or that – the medications we have
available in New Zealand are for other conditions and are needed for those people!
“If and when we have treatments that work, then we will have to consider how we source them – which may include
deliberately going off patent and getting pharmaceutical companies in New Zealand to make them.”
No conflict of interest.
Professor Kurt Krause, Department of Biochemistry, University of Otago, comments:
“Direct acting antiviral drugs are being sought that target coronavirus in the hope that these drugs might serve as a
bridge until a vaccine is developed. Since both drug and vaccine development take such a long time, interest has arisen
in already approved drugs that can be repurposed to target COVID-19. To date these repurposed drugs fall into 3 main
groups – polymerase inhibitors, protease inhibitors and other.
“Polymerase inhibitors include some of the most promising options and the notable members of this group are remdesivir,
galidesivir and favipiravir. They work by blocking the enzyme that allows the virus to replicate its nucleic acid coding
strand. If a virus cannot replicate its nucleic acid, it cannot replicate. Remdesivir is approved for use in animals
against diseases like FIP (Feline Infectious Peritonitis); it’s being evaluated in a small clinical trail in China and
results are due next month. Favipiravir was developed in Japan and has shown early promising results, but nothing has
been published in the peer reviewed literature yet. Galidesivir is a polymerase inhibitor that was partly developed in
NZ and has activity against coronavirus. It is being considered now for further studies and is notable for its strong NZ
“Protease inhibitors are a major drug class in use against HIV. For HIV they work by blocking an enzyme that processes
proteins that the virus needs for growth. During the SARS epidemic it was discovered that Kaletra (lopinavir/ritonavir),
a common anti-HIV drug, seemed to help coronavirus infected patients. Early data on its use for coronavirus infection
suggests weak to no activity, but it was an early study with small patient numbers.
“Another repurposed drug being studied is camostat mesylate. Like Kaletra it is a protease inhibitor but apart from that
they are very different. Camostat meslyate inhibits a completely different protease that is used by coronavirus to
mediate its uptake into cells. The good news that is that camostat is already used in people but for a non-infectious
condition – chronic pancreatitis, but the cautionary note is that camostat has not yet been used in people for
“The final drug in this repurposed grouping is in the “Other” category. It is called chloroquine. Chloroquine is an
antimalarial drug in long use especially in travel medicine. Turns out that it happens to inhibit SARS2-CoV replication
in the test tube and it has garnered wide attention because of it. Physicians are keen to learn if this observation
could be translated into success in living humans. A cautionary note is that chloroquine has been looked at before with
other viruses and was not found to be effective.
“Although many of these compounds can, and are, being given now in an off-label fashion, the best way to use them is in
a randomised controlled trial (RCT). That’s because RCTs allow us to learn quickly if a drug actually works or not. RCTs
have been essential in other viral epidemics and pandemics, like HIV for example, in learning the best most effective
way of treating infections. RCT evaluation of these candidates would be the best way to sort their utility in treating
No conflict of interest.
Associate Professor Mark Thomas, Clinical Molecular Medicine & Pathology, School of Medical Sciences, University of Auckland, comments:
“Auckland City Hospital is one of a number of hospitals in New Zealand and Australia hoping to recruit patients into two
clinical studies which will help to determine whether either an anti-malaria medicine, or an anti-HIV medicine, will
help patients with COVID-19 disease to recover.
“Patients admitted to hospital, either in a medical ward, if their illness is not severe, or in an intensive care
department, if their illness is severe, will be offered the opportunity to participate in the studies.
“If patients or their family provide consent, they will be randomly allocated to treatment with hydroxychloroquine (an
anti-malaria medicine), or with Kaletra (an anti-HIV medicine), or with a combination of both hydroxychloroquine and
Kaletra, or with a placebo.
“Neither the patients, nor their family, nor the medical team caring for the patients, will know which of the four
possible treatments the patients are receiving. It is what is called a double-blind study, which allows the effects,
potentially beneficial, or harmful, to be evaluated without any bias affecting the evaluation of the effect of each
treatment on patients’ outcomes.
“This clinical trial will help us understand whether these drugs are effective therapies for COVID-19.
“It is very likely that patients who are not participating in these studies will not be offered either or both of these
medicines, because their medical teams will not know until this and other similar trials are completed, whether the
medicines are helpful, or harmful, or have no discernible benefit or harm.
“Other medicines are being evaluated in other studies overseas, but, in general these other medicines are not registered
and available for use in New Zealand, and therefore not able to be used to treat patients in New Zealand.”
No conflict of interest declared.