Hydroxychloroquine and chloroquine are oral prescription drugs that have been used for treatment of malaria and certain inflammatory conditions chloroquine has been used for malaria treatment and chemo prophylaxis, and hydroxychloroquine is used for treatment of rheumatoid arthritis systemic lupus erythematosus and porphyria cutanea tarda. In this video we will talk about use, side effects, dosing and various studies on these medication in COVID-19 or SARS CoV-2. Do watch this video till the end Welcome to INTELLECT MEDICOS where learning is made easy by Dr. Shruti and Dr. Chirag Madaan. I am working as an ICU consultant at Apollo Hospital, New Delhi you can leave your queries or questions in the comment section below now let’s start. In some studies it has been found that both the drugs have in vitro activity against SARS-COV-2 and other coronaviruses and in some other studies it has been seen that hydroxychloroquine has relatively higher potency against SARS-COV-2, data to support the use of hydroxychloroquine and chloroquine for COVID- 19 are limited and inconclusive, still a tweet by US president Trump on 21st March 2020 claiming that a combination of hydroxychloroquine and as azithromycin has a real chance to be one of the biggest game changers in the history of medicine
accelerated a worldwide run on the drug with pharmacies reporting shortages within 24 hours. Now let’s first discuss how chloroquine or hydroxychloroquine acts or its mechanism of action. This is a host cell having lysosome inside cytoplasm and ACE2 receptors on its outer surface which helps in attachment of the virus. COVID- 19 virus has spike proteins on its outer surface for the attachment to the host cell Chloroquine and hydroxychloroquine interferes with the glycosylation of ACE2 receptors and blocks the virus fusion with the host cell therefore the binding of the virus through the receptors on the cell is impeded and infection is consequently prevented. Once hydroxychloroquine and chloroquine enter a Cell they are both concentrated in the organelle with low pH such as endosomes and lysosomes these drugs increase the pH of lysosomes creating problem in cleavage of the surface spike proteins. Without the cleavage function replication of and infection by CORONAVIRUS are blocked hydroxychloroquine and chloroquine are considered to be immunomodulators rather than immunosuppressants preventing t-cell activation I’ll not go into further details about microbiology or virology, if interested I’ll share the link in the description to learn more about immunomodulation. Now coming on to the side effects of hydroxychloroquine common side effects include headache, dizziness, gastrointestinal upset and rash. Retinopathy is a serious side effect of hydroxychloroquine and regular ophthalmic monitoring is recommended for patients on long term therapy hydroxychloroquine or chloroquine can cause ventricular arrhythmias, QT prolongation and other cardiac toxicity which may pose particular risk to critically ill patients. In this ECG you can see QT interval, which is prolonged. In this particular example ideally you should check for corrected QT interval which is called as QTc. A small study in France enrolling 26 treated patients and 16 non randomized controls showed that a hydroxychloroquine alone or in combination with azithromycin shortened the time to resolution of viral shedding of coronavirus 19 or COVID- 19. Based on this study, clinicians in many countries have begun using these medications in clinical practice and multiple randomized trials are being initiated however chloroquine hydroxychloroquine and azithromycin, they all prolong QT interval raising concerns about the risk of arrhythmic death or from concurrent use of these medications. American College of Cardiology has given risk scores for the drug associated QTC prolongation. These risk factors are age more than equal to 68 years, female sex, use of loop diuretic, serum potassium less than equal to 3.5 meq per liter, admission QTC more than 450 milliseconds, acute MI, more than equal to 2 QTc prolonging drugs, sepsis, heart failure or 1 QT c prolonging drug. Their maximum risk score is 21. if the score is less than equal to 6 point that indicates low-risk, 7 to 10 points moderate risk and more than equal to more than equal to 11 points that is higher risk potential. Absolute or relative contraindication for hydroxychloroquine azithromycin combination use in clinical research include first known congenital long QT syndrome, 2. baseline QTc more than equal to 480 milliseconds, 3. risk for more than equal to 11. In some experimental trials it has been shown that increased intracellular Zinc concentration are known to efficiently impair replication of corana virus by inhibiting RNA dependent RNA polymerase so some physician are using a combination of HCQ – that is hydroxychloroquine, azithromycin and zinc, although this is not proven yet. Dosing recommended by some studies are as follows treatment: HCQ that is hydroxychloroquine 400 milligrams twice a day on day one and then 400 milligrams once a day for five days. Azithromycin 500 milligram once a day for five days whereas for the prophylaxis hydroxychloroquine is to be taken as 400 milligram twice a day on day one and then once a week for seven weeks recently, randomized study from China in patients with mild to moderate COVID- 19 found NO difference in recovery rates. These drugs should be used only for, first of all treatment of COVID- 19 positive patients, 2. as a prophylaxis for asymptomatic healthcare workers involved in care of suspected or confirmed cases of COVID- 19 and also for asymptomatic household contacts of laboratory confirmed cases. Hydroxychloroquine and chloroquine in treating COVID-19, they should avoid misuse of hydroxychloroquine and chloroquine for prophylaxis of COVID- 19 because there are absolutely NO/LIMITED data to support this. Recently theyre have been reports of use of ivermectin, an anti-parasitic agent in the treatment of COVID-19. It’s not proven yet I will come up with new video if any update in the treatment or management comes. Till then, take very good care of yourself and your loved ones, take appropriate precautions like good hand-washing refrain yourself from going to the marketplaces.
COVID-19 UPDATE: HYDROXYCHLOROQUINE | WHEN & HOW TO USE, SIDE EFFECTS, MECHANISM, DOSING !
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