Originally Posted by pondering_it_all
R0 really has a fixed "infectability factor" from the virus, times a behavior factor. If we all had a perfect quarantine, R0 would be 0. If we had everything wide open it could be 5.7 or even higher. It's up to us which one we want.

As for the adverse cardiac events, Rheumatologists have prescribed billions of doses of hydroxychloroquine for their RA and lupus patients for years, at exactly the same dosage used for Covid-19 patients. And Covid-19 patients only get it for a few weeks. Those RA and lupus patients get it for years and years because their disease is chronic. They do see QT elongation, but it never results in cardiac arrest at that dose. A Brazilian study with chloroquine and more than double the dosage did see some cardiac events, but chloroquine is 5 times stronger than hydroxychloroquine. So that was like 10 times the usual dosage. As far as I know, hydroxychloroquine is still the standard of care for RA, lupus, and malaria.

Doctors have also found that Covid-19 is actually a disease of the endothelium (lining of blood vessels) rather than the lungs. Those cells also have ACE II receptors. That's why people still have compliant lungs but hypoxia: The capillaries in their lungs are screwed up. But so are their blood vessels everywhere. In the heart, the liver, the kidneys, the brain, the gut. That's why they get strokes. That's why they get massive clotting. So acute cardiac events in very sick Covid-19 patients probably have more to do with embolisms than QT elongation.

But that aside, very sick Covid-19 patients are not going to be helped by hydroxychloroquine, and very probably by remdesivir. You have to give them as soon as you think somebody has the virus, instead of just sending them home to see if they get sick enough to need oxygen in the hospital. The idea is to prevent the virus from replicating any more. As virus invade cells they are consumed by the replication process. If replication fails, they "die out". If you save your limited supply just for the sickest patients, retrospectively it will look like it makes things worse compared to no antiviral treatment. That's exactly what they did in that VA study. It didn't make it worse, they just gave it to dying patients.

These are attractive ways of thinking but some of what you're saying is contradicted by some of the data. Like I said, there's been studies of HCQ in milder cases, equally useless, and the VA study continued to show disadvantage for the treated arm even after adjustments for severity of illness.

As for the use of HCQ for 70 years with no big problems for malaria, RA, and lupus, I continue to strongly disagree with you that this anticipates safety for use in COVID-19. Like I said a number of times already, safety is disease-specific. I don't doubt that HCQ is safe for malaria, RA, and lupus patients, but I do doubt that it is safe for COVID-19 patients, as it adds cardiac toxicity to an already banged-up heart, given that the virus causes severe myocarditis, which is not the case for malaria, lupus, and RA.

Please take COVID-19 seriously; don't panic but don't deny it; practice social distancing (stay 6ft from people); wash your hands a lot, don't touch your face, don't gather with too many people, so that you help us contain it.