31 May Cholorquine

Dear colleagues

1. To chloroquine or not to chloroquine?

• Erickson reminds us of the narrow therapeutic range with cardiotoxicity (arrythmias), vasodilatation (hypotension) and seizures (attach 1).
• Rodrigo et al summarizes results in various viral infections (HOV, HCV, Dengue and COVID) and concludes that the evidence of therapeutic potency is very weak (attach 2)
• Das et al finds no evidence of therapeutic effect in 12 selected studies (attach 3)
• Shah et al were not able to make firm conclusions on prophylactic use, because of lack of clinical evidence (attach 4)
• Mehra et al have reviewed a large set of international data and found no evidence of therapeutic benefit by either chloro or hydroxychloro with or without macrolide. They all showed however a strong association with ventricular arrthymias (Fig 3 p. 7)  and were an independent predictor of mortality (Fig 2 p. 6). (attach 5)
• It is a very heated debate: in Brazil a failed trial led to death threaths… (attach 6)

To be honest with you, I cannot critically judge all the methodological ins and outs, which have already been discussed on all kinds of fora. As an enthusiast immune-virologist, I’m really impressed by all the possible indirect effects of chloroquine on the immune system.  But, in the end, it all reminds me too much of the early days of HIV: as long as we did not have AZT, we “repurposed” several drugs with very doubtful results.  So, dear colleagues, if you see me on one not-so-fine day at the Emergence Department with a bad COVID-19, please give me oxygen, antipyretics and maybe some antibiotics.  If you have Remdesivir, I’d like to try it, but leave chloroquine out of your cocktail.   Thank you very much in advance.

As you could understand , I’m not a chloroquine fan, but a scientist has to consider all arguments. The paper by Mehra has already inspired WHO and other agencies to dissuade or pause further CQ trials, but it is seriously criticized, because it is an observational study and has some flaws. Thus, it is possible that more sick people preferentially obtained CQ and therefor died more.  You can read more in the first attachment.

If a well-performed trial shows that I’m wrong, I’ll be the first person to inform you.  But if not, I close the chloroquine chapter.