The Antimalarial drugs chloroquine, and hydroxychloroquine which is its counterpart come with two hypotheses. First, as studies prove chloroquine has a weak base, it prevents the virus from attacking the cells through endosomes and protects them from damage. This also prevents the virus from attaching to porphyrin in RBC which once again prevents the release of iron. If the iron is released in the blood it produces toxicity in different organs and results in inflammation.
Chloroquine also acts as an immune-modulator decreasing inflammation and the severity of the disease.
There are two ways of presenting coronavirus, one of which is with patients with respiratory symptoms while some patients may experience multi-organ involvement and shock. Chloroquine also decreases the severity of respiratory symptoms in few cases
Some of the patients may be sensitive to chloroquine toxicity. This chloroquine has to be given to patients with a lower dosage, where about 400 mg should be used. Few studies have shown that when administered at a high 600 mg dosage, it has more toxicity that can lead to arrhythmias, a condition in which the heart beats with an irregular or abnormal rhythm. So, could lead to sudden deaths because of cardiac arrests particularly among the elders. Also, people with QT prolongations in ECG may also produce arrhythmias when they are given chloroquine.
Further other factors, such as the age of patient, whether they have comorbidity like heart attacks or are on some form of cardiac medicine. It is good to do ECG before the dosage is given to them also monitoring them daily.
The drug acts competitively, it does not function directly on the virus, instead of the virus invading the cell, the chloroquine goes and attaches there so the virus would not cause much damage.
Another recent work showed that the plasmodium vivax, i.e. the malaria-producing organism, has the same genomic sequence of 93 per cent resemblance to the coronavirus. It indicates the fact that some immunity would have evolved in Indians when exposed to malaria organisms. There is some immunity to fight the infection when the coronavirus infects, which gives us the second hypothesis on the antimalarial drug.
Despite no vaccine or specific treatment for COVID-19, chloroquine antimalarial drugs and their derivative, hydroxychloroquine, have been making headlines for the novel coronavirus infection as possible, with no definitive proof that they can cure or avoid the respiratory disease. Such medications have been reported to increase the risk of cardiac arrest, too.
Risk of Cardiac Arrest:
Factors such as age and if patients are on some form of cardiac medications, it has to be discussed with a doctor to reduce these risks. For QT interval, an ECG needs to be performed and they have to track and give the patient a proper dose to prevent excessive dosages. There are few studies that have shown improvement whilst a few others have toxicity
Self-protection against Malaria amid the COVID-19 pandemic:
With the start of the rainy season, people should be cautious and preferably monitor collections of water that is taking place in their surroundings where the mosquito can breed. Mosquito repellents should be used and if anyone is having fever, get the blood test done. The season is also vulnerable to Malaria, Dengue and hence people must be alert and take precautionary measures at earliest.
Use of malaria drugs or vaccines in near future:
Much like the H1N1 vaccine, this vaccine can be used for people with chronic respiratory illness, as well as for people with other pre-existing comorbidities such as diabetes, heart disease and hypertension.
But the coronavirus can reinfect again if there is a change in the genetic sequence coronavirus. Individuals can get a second infection.
The vaccine now given may not be effective for the change of genomic sequence later, as the days go by it will be understood and it will rely on the body to immune itself to the reaction.
Similarly, as there is no vaccine for malaria, as it keeps changing its genetic sequence. If there is a similar instance here and the body is not compliant with the new virus detection it may not respond, it all depends on how it eventually happens.