Be cautious about chloroquine

As I said yesterday, I find the reports of chloroquine/hydroxychloroquine activity against the coronovirus very interesting, but preliminary. There has as yet been no well-controlled trial, and unfortunately the effects seen are still the sort of thing that can look exciting but disappear when you look closely. I mean that. It happens all the time – ask anyone else who does drug research for a living. If this drug isn’t useful, then sending hundreds of millions of people out to swallow all of it that they can find will be a massive waste of time and money, and will actively harm people besides. This is not a benign compound; it should only be taken when you have a solid expectation of benefit, and (saying it again), we don’t yet have that. Better trials are cranking up right now: please, wait for those. The generic drug companies (Teva and Mylan, I’ve seen so far, and there’s this) that are cranking up production are doing the prudent thing – if this reads out well, we’ll need a lot of it. But we’ll need to give it to people who are in bad shape from the viral infection, too, remember that, and I fear that a lot of people around the world are just starting to take it now in hopes of a prophylactic effect, which is (saying it again) a bad idea.