With the world battling against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which has had an impact on millions of lives and puts a questionable remark on the advancement and development of research. The outbreak that was indigenous to Wuhan, China and later was declared as an international public health emergency in the start of 2020 by the World Health Organisation (WHO). These are enveloped positive sense single stranded RNA viruses belonging to the family of Cornoviridiae which have caused damage to organ systems of various vertebrates. Studies have shown that common symptoms of the virus include coughing, sneezing, fever, body ache and even pneumonia. The incubation period of virus from as early as 5 days to 14-day long period, for a patient to be called prone to coronavirus. The alarming increase and spread of the virus has been a serious concern worldwide and is termed as a pandemic, the major question posed due to the virus is the dearth to discover an effective treatment against it. Hence, in a dire need of finding a cure the pandemic has led the clinicians to find other medications which have proved to be effective for other diseases in the past.
One such rising hope which has emerged during this trial times is the use of Hydroxychloroquine, an anti-malarial drug. The medication is also used for treatment of auto-immune diseases such as rheumatoid arthritis and systemic lupus erythematosus. The prevalent characteristic of drug such as immunity regulation, antithrombotic activity, and inflammation improvement and extant anti-viral properties has been used as an alternative against the infection. The first reporting evidence that HCQ might work came from a test-tube data, post the reporting there have been hundreds of trials conducted worldwide. There are many combinations and permutations used in order to use the drug, some of which are usage in low or high dosages or combination with other drugs such as antiviral compound favipriravir but one which took the major limelight was the combination of HCQ with a second- generation macrolide such as azithromycin. However the use of this treatment for COVID-19 is based on few cases which have shown inconclusive results in many trials. Researchers all over the world have conducted experiments in order to understand the efficacy of the drug against the virus, one such study by a Chinese literature illustrated that when certain cells were infected with the virus, the drug was able to prohibit the viral replication with just the usage of standard dosage of the drug. The study showed that drug was able to increase the endosomial ph and interfere with the glycosylation of cellular receptors of the virus.
Apart from that the analogy between chloroquine and HCQ is to be considered, the only difference between them is the additional hydroxyl moiety in one terminal in HCQ which can act as a week base and change the ph of acidic intracellular organelles. It is also suggested that both when used together can act as powerful tool against COVID-19 but due to constraint of time, the research on whether HCQ has similar effect alone is still unclear. The potent applicability of HCQ is enhanced due to additional hydroxyl molecule which makes it less permeable to blood-retinal barrier and faster clearance from retinal pigment cell impacting a less risk for retinal toxicity. Therefore, in comparison with chloroquine it has proved to be safer option for use due to these prevalent characteristics. In addition, HCQ acts effectively on other intracellular bacterial infections such as Coxiella burnetii (Q fever) and Tropheryma whipplei (Whipple’s disease). It also suggested that the prevalent immunomodulatory effect of the drug could also enhance the activity of the drug in order to kill the virus. In terms of providing the dosage of the virus, several studies have shown variance for e.g. Italian section of Infectious and tropical diseases recommend the use of drug as 200 mg for 10 days, although the treatment can vary from 5 to 20 days depending on the severity of the infection. The treatment is suggested for patients suffering from mild respiratory symptoms to severe respiratory failure, in most cases resulting to death. However, in contrast there have been studies which suggest as of how there have been no benefit achieved by use of HCQ, when used alone or in combination with a macrolide. In some cases when the drug was provided during early diagnosis of COVID-19 actually worsen the situation leading to ventricular arrhythmias or even death. The convincing evidence emerged from the established fact that HCQ has a known relationship with electrical instability concerned with cardiac toxicity. The mechanism leads to blockade of her potassium channels which lengthens the ventricular polarisation and under specific conditions can result in the ventricular arrhythmias. In the case of COVID-19, can be delineated by two parameters: viral replication followed by a systemic inflammation. These parameters when used as a weapon for a fight against the COVID-19 by HCQ or with a combination of macrolide increase the QT interval (a measurement used to assess electrical properties of heart) and pose a risk of sudden cardiac death. Hence, it can be stated that in major cases HCQ has caused no benefit against the fight of COVID-19. Apart from that, WHO is still undergoing certain soliditary trials in order to save the humankind from the further damage by this virus. Additionally with the efficacy and safety of the drug against corona virus is still unclear.
Name of Author: Prachi Storewala
Position: OPF Trainee Intern