[BostonCard]

And here it is... the first randomized, placebo-controlled trial of hydroxychloroquine, this in use as post-exposure prophylaxis

https://www.nejm.org/doi/full/10.1056/NE...?query=TOC

Unsurprisingly, hydroxychloroquine doesn't prevent people from getting infected.

Results

We enrolled 821 asymptomatic participants. Overall, 87.6% of the participants (719 of 821) reported a high-risk exposure to a confirmed Covid-19 contact. The incidence of new illness compatible with Covid-19 did not differ significantly between participants receiving hydroxychloroquine (49 of 414 [11.8%]) and those receiving placebo (58 of 407 [14.3%]); the absolute difference was −2.4 percentage points (95% confidence interval, −7.0 to 2.2; P=0.35). Side effects were more common with hydroxychloroquine than with placebo (40.1% vs. 16.8%), but no serious adverse reactions were reported.

More trial results to come in the future, which will look at different patient populations, including those with confirmed disease.  But at the least, if you have been exposed to COVID-19 (defined as adults with household or occupational exposure to someone with confirmed Covid-19 at a distance of less than 6 ft for more than 10 minutes while wearing neither a face mask nor an eye shield (high-risk exposure) or while wearing a face mask but no eye shield (moderate-risk exposure).

There are some limitations: only about 2% of patients had laboratory confirmed COVID-19 (most of the rest of the "positives" were based on symptoms).  Secondly, a very small minority of patients were hospitalized (one in each arm) so if hydroxychloroquine works to reduce the risk of serious disease, you wouldn't have seen it in this study.  Third, patients had up to 4 days from the exposure to start prophylaxis; it's possible that this time period was too late.  Fourth, some 65 patients didn't take their medication; that's a pretty high non-adherence rate.

Since they had the data, I wish they had analyzed the effect of mask wearing on the likelihood of developing COVID-19.

Still, I would not take hydroxychloroquine if I were exposed to COVID-19.

BC

[BostonCard]

And here it is... the first randomized, placebo-controlled trial of hydroxychloroquine, this in use as post-exposure prophylaxis

https://www.nejm.org/doi/full/10.1056/NE...?query=TOC

Unsurprisingly, hydroxychloroquine doesn't prevent people from getting infected.

Results

We enrolled 821 asymptomatic participants. Overall, 87.6% of the participants (719 of 821) reported a high-risk exposure to a confirmed Covid-19 contact. The incidence of new illness compatible with Covid-19 did not differ significantly between participants receiving hydroxychloroquine (49 of 414 [11.8%]) and those receiving placebo (58 of 407 [14.3%]); the absolute difference was −2.4 percentage points (95% confidence interval, −7.0 to 2.2; P=0.35). Side effects were more common with hydroxychloroquine than with placebo (40.1% vs. 16.8%), but no serious adverse reactions were reported.

More trial results to come in the future, which will look at different patient populations, including those with confirmed disease.  But at the least, if you have been exposed to COVID-19 (defined as adults with household or occupational exposure to someone with confirmed Covid-19 at a distance of less than 6 ft for more than 10 minutes while wearing neither a face mask nor an eye shield (high-risk exposure) or while wearing a face mask but no eye shield (moderate-risk exposure).

There are some limitations: only about 2% of patients had laboratory confirmed COVID-19 (most of the rest of the "positives" were based on symptoms).  Secondly, a very small minority of patients were hospitalized (one in each arm) so if hydroxychloroquine works to reduce the risk of serious disease, you wouldn't have seen it in this study.  Third, patients had up to 4 days from the exposure to start prophylaxis; it's possible that this time period was too late.  Fourth, some 65 patients didn't take their medication; that's a pretty high non-adherence rate.

Since they had the data, I wish they had analyzed the effect of mask wearing on the likelihood of developing COVID-19.

Still, I would not take hydroxychloroquine if I were exposed to COVID-19.

BC