Coronavirus: Hydroxychloroquine Probably Isn't the Answer

POTENCY

I really don’t know what to make out this. Yao and colleagues reported that the EC50 – the concentration which inhibits 50% of viral growth in cultured cells – is 5.42 micromolar for CQ (this makes it a very weak inhibitor) and 0.77 micromolar (a moderately potent inhibitor) for HCQ, making HCQ seven times more potent than CQ. You don’t see many 5 micromolar drugs out there, so this would give the edge to HCQ.

But Wang and colleagues reported that that number for CQ is 0.77 micromolar and didn’t give data for HCQ. To make matters worse, Liu and colleagues determined that the two drugs were about the same. Although the in vitro data seem confusing one can conclude that even if HCQ had only the same in vitro potency (unlikely) as CQ it would still be a superior candidate because larger doses could be given, which would (presumably) lead to higher blood levels of the drug.

WHAT’S GOING ON IN THE CLINIC?

A mess.

Right now, we aren’t even close to an answer. Without any results from randomized clinical trials, it is little more than a guessing game at this point.

2 Likes

On face value, this is not nearly potent enough to be a useful drug.

1 Like

https://doi.org/10.5582/bst.2020.01047

https://dx.doi.org/10.1038%2Fs41422-020-0282-0

1 Like