Scientists are exploring whether an inexpensive anti-malaria drug could be an effective treatment for coronavirus.
Chloroquine has been used for decades to prevent people catching malaria, a disease spread by mosquitos.
As the race to find a cure to halt the coronavirus pandemic continues, scientific attention has turned to the drug’s anti-viral effects.
On Thursday, US President Donald Trump and the US Food and Drug Administration commissioner Dr Stephen Hahn announced that chloroquine was one of a number of approaches being tested to tackle Covid-19.
The University of Minnesota revealed on Tuesday that it was launching a clinical trial of whether hydroxychloroquine, a derivative of chloroquine, can prevent people catching coronavirus.
Trial volunteers who have been exposed to someone with known Covid-19, but who are not ill, will be given hydroxychloroquine to test whether it can stop the illness developing or reduce its severity.
According to a laboratory test conducted by the Wuhan Institute of Virology in China, chloroquine was found to be “highly effective” in controlling Covid-19 infection.
The World Health Organisation (WHO) has also included chloroquine as one of the drugs being prioritised under its global Solidarity Trial – an international study bringing together various nations’ efforts to test potential coronavirus treatments.
Other drugs being focused on for testing include remdesivir, in development as an anti-Ebola virus treatment, and lapinovir/rotinovir, an HIV drug.
For over 10 years there have been studies reporting the anti-viral effects of chloroquine ... against flu and Sars, raising hope of activity against the current pandemic virusDr Andrew Preston, University of Bath
Dr Andrew Preston, reader in Microbial Pathogenesis at the University of Bath, said: “Chloroquine is better recognised as an anti-malarial drug.
“It is cheap, considered relatively safe in humans and has been used for over 70 years.
“However, for over 10 years there have been studies reporting the anti-viral effects of chloroquine, or its common derivative hydroxy-chloroquine, against flu and Sars, raising hope of activity against the current pandemic virus.”
Dr Preston said studies showing chloroquine’s anti-viral effects during the previous Sars virus outbreak received “relatively little attention” as it died away.
He highlighted recent research in Marseille, France, where a trial of chloroquine treatment on 20 Covid-19 patients in hospital saw 70% considered to be cured after six days.
Dr Preston emphasised more scrutiny was needed of the results as well as larger controlled trials on chloroquine’s effectiveness.
Since it has a long history of clinical use, the safety profile of chloroquine is well-established and it is cheap and relatively easy to manufacture ...Professor Robin May, University of Birmingham
“But in among the oppressive darkness of the current situation, any glimmer of hope is very welcome,” he added.
Robin May, Professor of Infectious Disease at the University of Birmingham, said of chloroquine: “It is a drug that has a long history of use against malaria, essentially because it diffuses into red blood cells, making the environment within the cell less suitable for the parasite to live in.
“Since it has a long history of clinical use, the safety profile of chloroquine is well-established and it is cheap and relatively easy to manufacture, so it would – theoretically – be fairly easy to accelerate into clinical trials and, if successful, eventually into treatment.”
Last month, it emerged that the UK’s Department for Health and Social Care had banned the “parallel export” of chloroquine and ritonavir/lopinavir.
Parallel exporting occurs when companies buy medicines meant for UK patients and sell them on for a higher price in another country.