I look forward to hearing of the results of the trials you mention in NY
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Can anyone explain why an anti-malarial drug, or that drug in combination with an antibiotic, might be expected to treat a viral disease?
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Most malarial drugs have uncertain mechanisms, and these two are known to form reactive species and to be quite ādirty,ā hitting multiple targets. This part of why they have low therapeutic indices. For these reasons, these drugs might be fairly non-specific in their action.
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It is speculated to affect endosomal uptake, which is important in the initial stages of infection. Its mechanism against malaria MAY be that it selectively raises the pH of vacuoles and/or because it inhibits the degradation of heme, which MAY be selectively toxic to parasites inside red blood cells. Like many successful drugs, as Joshua says, it does a lot.
Chloroquine works quite well to inhibit SARS-1 infection in cultured cells, but doing what it does to all of the endosomes in all of oneās cells also affects a wide variety of biological pathways.
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I see. Any idea on what the antibiotic is supposed to contribute?
Which, I emphasize, is a highly non-specific effect, often caused by physical properties that enable acid trapping.
At the same time, this is a drug that does a lot of different things. It is very difficult to tease out what is actually relevant to efficacy.
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Exactly. And more negative trials are appearing:
https://www.sciencedirect.com/science/article/pii/S0399077X20300858
I did hear of a possible and interesting mechanism for chloroquine anti-viral activity. It turns out that chloroquine is a zinc ionophore resulting in increased intracellular zinc which inhibits the viral RNA dependent RNA polymerase.
I saw that too; as a result, Iāve been taking a zinc supplement, but only at the RDA, which requires cutting up the 50-mg tablets. Thereās not nearly the risk with that as there is for chloroquine.
Iād be interested in othersā opinions of the trials I linked to above.
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Iām not big on supplements, but in winter (half the year in Calgary) I take C, D, and zinc.
I had an assignment at a tropical mine when a position opened up due to a promotion, which came about when the department head died of malaria. I had the malaria medication at the ready, but did not use them as a prophylactic as prescribed. No one at the mine did because of side effects from long term use. There was not one exception. I sure wouldnāt start popping chloroquine now on the feeble strength of what is known at this point.
Pretty clear evidence that chloroquine isnāt a magic superdrug for this virus. Beyond that . . . theyāre small studies, and one is uncontrolled. More data needed.
We are going to close this topic, and move here: Hydroxychloroquine, an Idea that Could Kill People.
The OP has a blog with more up to date information.