On 20 March 2020 the World Health Organization (WHO) announced it would be launching a megatrial named Solidarity as a mass effort to find the most successful existing drug to treat severe symptoms of Covid-19.
Finding a proper treatment might not only buy time while a vaccine is still in the pipeline, but it can also save lives and aid with faster recovery, making much-needed beds and equipment in overcrowded hospitals available, as the pandemic sweeps the globe.
One of these drugs is something that has been around since the 1940s. Chloroquine phosphate was manufactured to treat malaria.
US president Donald Trump was particularly optimistic about the use of this drug as a treatment for Covid-19. However, the safety of chloroquine for the purpose of treating Covid-19 has been questioned as cases of chloroquine poisoning had been reported in Nigeria.
But what is the deal with the drug?
Why a malaria drug for Covid-19?
During the first stage of the new coronavirus outbreak in Wuhan China, doctors in the area recommended the drug to treat infected patients according to their guidelines. This reasoning comes from promising results from a small clinical study.
Clinical trials on about 130 patients demonstrated the drug’s ability to reduce the severity of the illness and speed up virus clearance, according to China’s Ministry of Sciences and Technology.
The possibility of chloroquine being used to treat a different coronavirus, namely SARS, came up in a 2005 report published in the journal Virology. The study revealed that chloroquine could prevent the spread of the virus that caused the SARS outbreak in 2003.
This guideline was short-lived as a study done by the Wuhan Institute of Virology mentioned the drug can kill an adult, dosed at twice the daily amount recommended for treatment, which is one gram.
How does chloroquine work?
Chloroquine treats malaria by killing off the single-cell parasite that causes the disease. It also works for viruses as follows:
Chloroquine interferes with a virus' ability to replicate in two ways – it alters the pH levels of the endosomes, compartments that the virus enters, and prevents the virus from plugging into the ACE2 receptors.
What are the side-effects?
While generally safe to use in the treatment of malaria, chloroquine has some known side-effects such as an upset stomach, diarrhoea, abdominal cramps, headaches and mood changes.
It may cause problems with prolonged use in patients with liver or kidney dysfunction and immunosuppression, but have been reportedly well-tolerated in Covid-19 patients, despite the fact that there is not yet enough evidence or clinical trials.
What caused the poisonings in Nigeria?
Bloomsberg reported that two people were hospitalised in Lagos, Nigeria, after the demand for the drug surged during the current, new coronavirus outbreak. "Chloroquine is still in a testing phase in combination with other medication and not yet verified as a preventive treatment or curative option," Oreoluwah Finnih, senior health assistant to the government of Lagos, stated in an interview.
Could the drug work for Covid-19?
While chloroquine phosphate is a successful malaria treatment, it has not yet been approved by the Food and Drug Administration (FDA) or the WHO to safely treat Covid-19.
In February, a research group led by virologist Manli Wang of the Chinese Academy of Sciences found that chloroquine successfully stopped the spread of the Covid-19 virus in cultured human cells (in vitro). Preliminary reports from China, South Korea and France suggest that the treatment is at least somewhat effective in treating human patients.
What about hydroxychloroquine?
Hydroxychloroquine is a less “toxic” chemical relative of chloroquine, and is used to prevent and treat malaria in those who can’t tolerate chloroquine.
Because of a shortage of chloroquine in China, and the toxicity of chloroquine that can be fatal if overused, Wang’s team also tested hydroxychloroquine in primates and found that it had the same effect, according to a report published in Cell Discovery.
Clinical trials are, however, still ongoing.
The rising demand for chloroquine
According to statement by the FDA, success from clinical trials for chloroquine as a Covid-19 will make the demand for this drug spike, and they will insure that the demand is met in the US.
Despite ongoing trials, Austell Pharmaceuticals has offered to donate 500 000 tablets of chloroquine phosphate to the government according to a statement.
The company has made this decision on the fact that there is ongoing evidence that the drug could help treat severe Covid-19 symptoms and make much-needed space in hospitals available.
Austell also stated that the use of chloroquine phosphate was adopted in the South African guidelines for the clinical management of Covid-19.
What do experts say?
Although clinical trials are still pending, the advantage of trying out chloroquine and hydroxychloroquine as Covid-19 treatments is that the drugs' safety profiles are well understood, stated Dr Len Horovitz, an internist and pulmonary specialist at Lenox Hill Hospital in New York City.