Question What is the truth about hydroxychloroquine ?

Jul 2, 2020
What is the truth about Hydroxychloroquine ?

How much is politics a factor in this ?

I can find little evidence that hydroxychloroquine does harm, its side effects are well researched and known - even the WHO references to stopping HCQ trials are vague - see link at the end

Prof Horby who lead one of the studies referred to that concludes HQC does not fight covid-19 sets out that the negative observational study about HQC retracted from the Lancet did a lot of damage and

"the suspension of numerous well-designed [HQC] clinical completely unjustified." (Links at the end)

Many observational studies peer reviewed and otherwise of patients in hospitals have shown hydroxychloroquine is effective in treating covid-19

The latest peer reviewed study from Italy published 29th July sets out how Hydroxychloroquine was randomly given, that those being treated had no other medication and that there was a control group. The result was a 66% lower death rate amongst those treated with hydroxychloroquine.

This is a very similar result to a US hospital study and without many of the "flaws" cited in the US study (see links at the end)

A total of 539 COVID-19 hospitalised patients were included in our cohort in Milan, from February 24 to May 17,2020 of whom 174 died in hospital (day 14 probability of death: 29.5%–95%CI: 25.5–34.0). We divided a subset of our cohort in three groups who started treatment a median of 1 day after admission: those receiving hydroxycholoroquine alone (N = 197), those receiving hydroxycholoroquine + azithromycin (N = 94), and those receiving neither (controls) (N = 92). Of the latter group, 10 started HIV antivirals (boosted-lopinavir or –darunavir), 1 teicoplanin, 12 immunomodulatory drugs or corticosteroids, 23 heparin and 46 remained untreated. The percent of death in the 3 groups was 27%, 23% and 51%. Mechanical ventilation was used in 4.3% of hydoxychloroquine, 14.2% of hydroxycholoroquine + azithromycin and 26.1% of controls. Unweighted and weighted relative hazards of mortality are shown in Table 1. After adjusting for a number of key confounders (see table), the use of hydroxycholoroquine + azithromycin was associated with a 66% reduction in risk of death as compared to controls; the analysis also suggested a larger effectiveness of hydroxychloroquine in patients with less severe COVID-19 disease (PO2/FiO2 > 300, interaction p-value<.0001). Our results are remarkably similar to those shown by Arshad et al.

Some important weaknesses of the analysis by Arshad have been pointed out (Lee et al., 2020) but not all of these apply to our study. Our propensity scores include some of the potential confounders that were missing in the analysis by Arshad (e.g. calendar day of admission, disease severity, cardio-vascular disease (CVD), baseline plasma CRP); second, we have excluded people receiving other drugs which could have biased the effect of hydroxychloroquine when used in combination. Third, although residual confounding is a possibility (e.g. people with CVD were more frequent in control), people in the control group were more likely to undergo mechanical ventilation that is a conservative bias. These results from two different real-life settings (Italy and USA), are conflicting with those of two large randomised trials (Horby et al., 2020, World Health Organization, 2020). Although unmeasured confounding remains the most likely explanation for the discrepancies, a robust meta-analysis is still lacking and we question whether hydroxychloroquine should be further tested. When best to start treatment is also a question that needs to be addressed in ad-hoc randomised studies.

Treatment with hydroxychloroquine, azithromycin, and combination in patients hospitalized with COVID-19
Henry Ford COVID-19 Task Force1

The WHO states

interim trial results show that hydroxychloroquine and lopinavir/ritonavir produce little or no reduction in the mortality of hospitalized COVID-19 patients when compared to standard of care. Solidarity trial investigators will interrupt the trials with immediate effect.

Peter Horby, professor of emerging infectious diseases and Global Health in the Nuffield Department of Medicine, University of Oxford, said: 'The Lancet publication by Mehra et al has had major adverse impacts, resulting in the suspension of numerous well-designed clinical trials. This is completely unjustified.

'Even if the results were correct, observational data such as this, with its inherent weaknesses, should not be used to stop trials which will provide definitive and actionable answers.'

Professor Stephen Evans, pharmacoepidemiology at The London School of Hygiene and Tropical Medicine, said: 'In retrospect many readers and decision makers may well have placed too much reliance on that paper.'

Peter Horby, Professor of Emerging Infectious Diseases and Global Health in the Nuffield Department of Medicine, University of Oxford, and Chief Investigator for the trial, said: ‘Hydroxychloroquine and chloroquine have received a lot of attention and have been used very widely to treat COVID patients despite the absence of any good evidence. The RECOVERY trial has shown that hydroxychloroquine is not an effective treatment in patients hospitalised with COVID-19.
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