The number of patients already overwhelmed the healthcare system.

Per some interview with some Chinese doctors who battled COVID19, they said that for many critical patients, their viral load is actually low, but the virus had caused damages to all parts of their bodies thus antiviral isn't going to do anything significant at that stage.

This might suggest chloroquine could be helpful at earlier stage of COVID19, to help prevent patients developing into server/critical stage, which would still be a very good thing if hold true.

It might be, we don't know how the Italian system would cope without it. Due to increasing but low test numbers, we don't know how many infected patients there are in Italy. The situation in some hospitals is severe, but it has been for ~2 weeks.

I believe with the number of patients they have, they would've updated the guideline if it wasn't effective at all. But how effective it is we don't know. If a large percentage of some areas is already infected but the health system is still in the state it's in now, it could actually be a good sign. If the current numbers are realistic (which I don't believe at a positive test rate of >30%), it's probably not. We simply cannot know.

Thanks for this reference, it seems they are proposing 2 potential treatments (p. 13) for the more severe patients

> Il trattamento deve essere accompagnato da trattamento antivirale (lopinavir/ritonavir o remdesivir + clorochina/idrossiclorochina) e/o steorideo (desametasone)

This is from the 13th of March so I guess there will be still some days until we see results of this (either positive or negative)

For the record since that decision day, the growth rate in the number of deaths in Italy has fallen in half[1]. In the 9 days from March 13 to March 22 the daily number of deaths grew 160% from 250 to 651. Prior to that, the same level of growth occurred in 4 days between March 9 (96 deaths) to March 13.

That seems like pretty strong evidence that the new treatment protocol is drastically decelerating the pandemic in Italy.

[1]https://www.worldometers.info/coronavirus/country/italy/

This does not make much sense to me. If it was effective, it should decrease the lethality rate, not the growth in the number of deaths which is much more affected by the actual number of cases. In the page you link you can see that lethality rate has not fallen. Also, as I wrote I'm pretty sure that I saw an earlier version of that document, dating IIRC to the beginning of the month, that prescribed more or less the same combination of chloroquine and antivirals as a first line treatment.

Does this doc record actual usage?

What are you basing "it has at best a marginal effect" on?

I have no clue how much it is actually used, couldn't find any info and fortunately I don't have any direct experience yet. If it is used, the lethality rate in Italian hospital definitely show it's not incredibly effective, at least in the way they are using it.