There is a lot of news speculation on Hydroxychloroquine right now. Does it work? Does it not? Are the risks of serious cardiac complications worth the benefits?
Since most of us do not have access to this drug, then the better question is what is its mechanism of action? And do we have something already available to us that can help? First, we need to understand a little more about the drug.
Benefit: There may be some benefit if you have COVID-19, but this is news according to some very poorly done studies in clinical trials. Most of the data is not in humans (in vivo), but in cell cultures (in vitro). This does not always translate well to humans. Is it good for prevention? The literature does not support it at this time.
Adverse Effects: Does it have some serious cardiac consequences? Yes, indeed, as well as liver toxicity and other side effects. Would I take it even if I had it available to me due to these side effects? No. I think once we understand one of its suspected mechanisms of action, then we may understand there are much better options available to us.
Mechanism of action: There are several purported mechanisms of action for this drug and its suspected antiviral benefit. One of these is by acting as a zinc ionophore, with benefits studied in cancer cell death. An ionophore is basically a substance that allows zinc to enter the cell. Zinc is a potent immune supporter and dampens runaway inflammation through downregulating IL-6, a potent inflammation inducer. It is also important in the upregulation of lysosomes which help kill viruses. This sounds like a good thing and it is, but there are other things that are much less toxic that can mimic these actions according to this paper.
Alternatives: It seems according to the above papers that flavonoids, a class of polyphenols (those wonderful substances in blueberries, strawberries, red wine etc. that give them their color) are zinc ionophores—quercetin and green tea extract (ECGC) being two that have been studied. They appear to be quite effective in helping transport zinc into the cell. The good news is that they easily supplemented both of these powerful antioxidants. Quercetin is associated with allergy prevention. ECGC may help with weight loss and has positive cardiovascular benefits. They definitely will not hurt and can only help your immune system.
Knowing the above, I would not worry about hydroxychloroquine and focus instead on a colorful diet with zinc supplementation and possibly adding in quercetin and/or green tea extract if you want the purported benefits of a drug like hydroxychloroquine, and you will definitely improve your immune capabilities.