According to this article, chloroquine and hydroxychloroquine could be effective treatments for Covid-19.

Assuming the drugs are well tolerated in clinical trials and seem effective at treating COVID-19, the FDA will take measures to increase the nation's supply, according to Hahn.

Assuming best case scenario, when could these drugs be made widely available to treat the disease? By "when," I mean how long is it likely to take?

  • After they conduct trials Mar 23, 2020 at 15:03
  • @GrahamChiu: How long is that likely to take? Mar 23, 2020 at 18:04
  • Best guess . a month Mar 23, 2020 at 20:40

1 Answer 1


Let's not get ahead of ourselves here.. chloroquine/hydroxychloroquine (and possibly in concert with azithromycin) have been touted over the past few days as a possible treatment regimen.

And there's some cause for that - the antiviral properties of chloroquine/hydroxychloroquine in vitro are broad and it's been trialed against various things (HIV, Ebola etc), however this hasn't always transferred particularly well into an actual treatment. And there's some research suggesting that it can successfully battle SARS-CoV-2 in vitro too. However, killing something in a petri dish is one thing, treating a disease in a human is another.

There has been some preliminary trials done - I believe there's been some fairly non-specific vagueness about it being promising when used in China and there's a relatively new study that's come from Gautret et al in France.

The Gautret et al paper looks promising - on the surface. It seems to suggest that treating people with a combination of hydroxychloroquine and azithromycin looks great:

Percentage of patients with PCR-positive..

Unfortunately though it's not that simple.. first up we aren't talking about a great number of people here. The entire study comprised 42 patients (16 of which were the control), which isn't a huge sample size. And any patients who were on the treatment who got worse were removed from the analysis:

Six hydroxychloroquine-treated patients were lost in follow-up during the survey because of early cessation of treatment. Reasons are as follows: three patients were transferred to intensive care unit, including one transferred on day2 post-inclusion who was PCR-positive on day1, one transferred on day3 post-inclusion who was PCR-positive on days1-2 and one transferred on day4 post-inclusion who was PCR- positive on day1 and day3; one patient died on day3 post inclusion and was PCR-negative on day2; one patient decided to leave the hospital on day3 post-inclusion and was PCR-negative on days1-2; finally, one patient stopped the treatment on day3 post-inclusion because of nausea and was PCR-positive on days1-2-3.

So the picture isn't quite as rosy as the graph makes it look. Some people on this treatment still got worse, one died.

It get's even shonkier (technical term) when you look at the large swathes of control patients who didn't have the PCR test done for viral loads:

Supplemental Table 1

They effectively only properly measured the viral loads for 4 of the 16 control patients, so trying to compare the groups is verging on meaningless.

So before we look at "when" they'll be widely available to treat SARS-CoV-2 I'd be more concerned with answering whether they should be used to treat it. Hydroxychloroquine is not exactly harmless - while less toxic to humans than chloroquine, it's not something to give lightly, it can have immunosuppressant effects, and in sufficient dosages can result in potentially lethal cardiotoxicity.

It may yet prove to be an effective treatment - and the WHO is trialing it (along with other potential treatments) as part of their mega-trial SOLIDARITY, but let's not get too excited just yet.

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