Thread by @nabarund

What happened when politicians promoted #hydroxychloroquine as a cure for COVID? People died from unnecessary side effects.

I reviewed the recent data from the Pfizer Global Safety Database in @DrugSafetyJ

link.springer.com/article/10.100…
open access

thread below #pharmacovigilance

Original data from Beyzarov et al. in
@DrugSafetyJ

link.springer.com/article/10.100…
(open access)

During a global emergency, making clever use of existing resources is a fundamental human impulse. But, the cavalier repurposing of hydroxychloroquine, chloroquine, and azithromycin during the COVID-19 pandemic has consequences.

Seven deaths from cardiac adverse events occurred with the off-label use of drugs whose power to prevent COVID-19 has been discredited. We now glimpse the tip of the iceberg amid a sea of well-intentioned but unsubstantiated promotion. More cases have certainly occurred.

The data come from a real-time global database of side effect reports that each pharmaceutical company is legally required to maintain. The Pfizer database used in this study receives around half a million reports each year.

Each report was medically assessed to establish the strength of the causal connection between the medication and the reported side effect.

Pfizer presented 1508 cases gathered during the first 8 months of the pandemic, mainly involving immunosuppressant/immunomodulating agents and anticoagulant/antithrombic agents, as well as corticosteroids.

Azithromycin is routinely used to treat bacterial respiratory infections; hydroxychloroquine can prevent malaria & manage autoimmune diseases. They are widely available and have been in use for a long time. Both factors contributed to perceptions of safety.

One-third of all off-label use reports came from France. Despite the global scope of the database, reports were most frequently from the USA, France, and Spain and may not be globally representative.

Most of the adverse events involved concomitant use of multiple medications, making it inherently difficult to disentangle individual drug effects. Half of the patients had underlying conditions that might predispose them to infection or the negative consequences of infection.

But while clinical trials were ongoing, would it have been fair to label lay media promotion of these drugs as misinformation? When does off-label use go from being a rational clinical decision to an unjustifiable risk?

We can point to 19 June 2020, when the hydroxychloroquine arm of the Solidarity trial was halted.
nejm.org/doi/10.1056/NE…

Within the swirling mass of digital communication, both whimsical pseudoscientific notions and well-reasoned hypotheses have the opportunity to find purchase. In hindsight, the underlying evidence for repurposing these specific drugs was flawed.

As public health professionals, it may appear that our responsibility ends when we support fact checkers by generating that novel kernel of evidence. But the reality suggests otherwise.

“Exposure to misinformation cannot simply be undone through fact checking, correcting, or debunking efforts... [social media] retractions are rarely successful at eliminating misinformation"
ncbi.nlm.nih.gov/pmc/articles/P…

What can be done when the other side wields a bullhorn against professionally cautious scientific voices? See the last section for guideposts
link.springer.com/article/10.100…

Thanks for reading, y'all

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