I decided to listen to a podcast about the drugs chloroquine and hydroxychloroquine. I thought this was a very topical podcast to listen to because there had been some rumours going round that these drugs could be used to treat the coronavirus, as sometimes old drug can help to treat new sickness.
Chloroquine is mostly known as an effective treatment and preventative for malaria, and the suffix “–quine” is an analogue of quinine, which is antimalarial drug which was discovered in the 1820s in tree bark, and it is used in herbal medicine. Chloroquine was then discovered over a century later in 1934 by the pharmaceutical Company BAYER, but it was kept away for a decade due to its high toxicity. It wasn’t until the US Army was in desperate need of antimalarial drugs in WW2 that it was used, so everyone became aware of its effectiveness as a prophylactic as well as treatment for malaria.
Chloroquine works by diffusing into the lysosomes in the malarial parasites. These are spaces inside the cell membrane that contain the enzymes and cofactors required for the parasite to safely breakdown haemoglobin in blood, and lock away the toxic haem products. Like the human stomach, the pH is lower inside the lysosomes compared to the rest of the cell and this acidic environment is what causes chloroquine to become protonated, which means it then can’t diffuse back out of the cell. Once inside the cell it causes a build-up of haem that ultimately kills parasite.
Sadly, resistance to chloroquine has started developing shortly after it came into use. And since the 1950s, resistant strains of malaria have appeared through most of the world. The American centres for disease control reports widespread chloroquine resistance in many countries such as Bangladesh, Benin and Brazil. Resistant strains have evolved the ability to pump chloroquine back out of the lysozymes, which prevents its mechanism from taking place. Hydroxychloroquine is another very structurally similar to chloroquine that is considerably less toxic, so it is seen as a safer option, but there are other drugs which are better recommended than these ones.
Chloroquine and hydroxychloroquine (also known as HCQ), are also used to treat other conditions such as lupus and rheumatoid arthritis, along with other non-malarial fevers. They are generally well tolerated with only mild side-effects. including headaches, nausea and skin rashes, but they can have some serious long-term effects such as a form of retinopathy, which can ultimately lead to blindness. Chloroquine also has a high overdose risk, due to its high toxicity, whereas HCQ overdoses are luckily very rare.
Chloroquine and HCQ are now in the news again after a while due to the COVID-19 pandemic which is infecting many people worldwide. In February 2020 South Korean scientists made the realisation that the drugs are effective in cell culture studies against SARS COV-2, the Coronavirus strain that actually caused COVID- 19. After some clinical trials being conducted in China and France, there were some confusing and conflicting results. There was good reasoning to believe that chloroquine could be a good candidate to treat the coronavirus, because it was shown to be effective (in vitro) at blocking the replication of a different coronavirus strain, which is responsible for severe acute respiratory syndrome(SARS).
Due to these promising results, The World Health Organisation has added chloroquine and HCQ to a list of 4 potential medication is to investigate, and different governments worldwide have funded further clinical trials into these medications. In the absence of a vaccine, drugs like these with unknown safety profile could be a lot safer to use.
But before all these results are received, the general public must be cautious. The hype and buzz around these initial results have already led to some countries stockpiling chloroquine and HCQ, and in response to this India has banned all exports of these drugs. Arthritis and lupus patients have started to lose access to their medication, and some people who have understandably become concerned of contracting COVID-19 have gone out of their way to self-medicate with chloroquine even though the Mayo Clinic warned that there is a high potential for drug-induced sudden cardiac deaths from due to off-label use. This is definitely had disastrous consequences, including the death of at least one person who took a non-medical preparation of chloroquine which is designed to kill parasites in fish tanks.
In my opinion it’s way too early to tell if chloroquine or HCQ will cause major benefits to this pandemic and help in treating the coronavirus. Because we still don’t have a lot of information about the virus it isn’t for certain if these drugs could benefit the pandemic, however this podcast has definitely sparked my interest in doing more research in the drugs that have the potential of treating COVID-19. Even though one of these drugs could be the potential cure, I think it’s too quick to jump onto this bandwagon and start meditating people because it could result in more casualties due to these drugs and it could cause more complications by having more patients in hospitals, and possibly even more deaths, and this will only overstretch and work the NHS a lot harder than it already has been. This would mean medical professionals can no longer supply the time and care for the patients who actually need it.
Nevertheless, this podcast definitely stressed the importance of following the rules of medical professionals in the government. By staying inside, we are maintaining social distance from other people and helping to reduce the risk and flatten the curve of coronavirus cases in the UK.