Hydroxychloroquine: from innocuous travel drug to dangerous poison

Hydroxychloroquine is back in the news. I remember getting offered this drug every time I told a doctor that I was going to a tropical country. The travel warning sites regarding malaria never seem to distinguish between rainy season (mosquitoes and occasional malaria) and dry season (tourists). So I would show up to the destination with a bottle full of malaria pills and find that nobody had seen a mosquito for the past three months.

As of January 2020, the drug was safe for everyone who was going to travel to a tropical country to take as malaria prophylaxis. You could take it for five years before even beginning to look for a side effect, according to this official government site: “CDC has no limits on the use of hydroxychloroquine for the prevention of malaria. When hydroxychloroquine is used at higher doses for many years, a rare eye condition called retinopathy has occurred. People who take hydroxychloroquine for more than five years should get regular eye exams.”

Today, however, now that we have 65.4 years of experience with the drug instead of 65.1, it is recognized by scientists as a dangerous poison. “What to Know About the Malaria Drug Trump Says He Is Using” (nytimes, May 19):

Here are the facts on hydroxychloroquine, which the president has promoted to fight Covid-19 despite warnings from the F.D.A. that it can cause heart problems.

There is no evidence that hydroxychloroquine can prevent coronavirus infection.

It is not safe for people who have abnormalities in their heart rhythms, eye problems involving the retina, or liver or kidney disease. Other possible side effects include nausea, diarrhea, mood changes and skin rashes.

The leaders of three professional societies in cardiology warned on April 8 in the journal Circulation that hydroxychloroquine and azithromycin could each cause dangerous disruptions in heart rhythm, and they wrote, “There are very limited data evaluating the safety of combination therapy.”

Now we know the truth!

Readers: Where do we stand on whether this drug has any effect on Covid-19? Is the science settled?

31 thoughts on “Hydroxychloroquine: from innocuous travel drug to dangerous poison

  1. (Full) Professor Dolores Cahill at the University College Dublin says it is criminal negligence that we are not offering hydroxychloroquine to seniors as a prophylactic against severe Coronavirus symptoms. Her bona fides are listed here: https://people.ucd.ie/dolores.cahill

    There are several interviews with her on YouTube stating her position. Here is one:

    Good News: “you’re Immune To COVID” – YouTube

    That video is quite short and to the point (ten minutes), if you can tune-out Del Bigtree’s slightly breathless interview style and his other disreputable views 🙂

  2. It’s amazing how the publicized danger profile of this drug has shifted so much. I had been waiting for the David Holtgrave/Albany study results to be released and they were, on May 11. Its findings were broadly in line with the scary Times story:


    Here’s the “For The Media” link to the full study:


    Everyone had hoped for a large and immediate beneficial impact of these therapies, but for this group of seriously ill patients, we did not observe a significant benefit of the administered drugs;

    Hydroxychloroquine taken in conjunction with azithromycin (compared to neither drug) was associated with significantly elevated levels of cardiac arrest even after statistical adjustment for sex, age, underlying health conditions, and more severe illness upon admission.”

    Scary stuff. But the study only concerned itself with patients who had already been hospitalized: “seriously ill patients.” It says nothing about prophylaxis, and I don’t know whether anyone has done a study about its effectiveness as a prophylactic among either asymptomatic or uninfected people. Why?

    I don’t think the science has even been done to answer that question!

    At the beginning of all this, intuitively I doubted that a malaria drug would help prevent a viral infection but then again, it’s prescribed for lupus and rheumatoid arthritis and the immune system is, for lack of better terms here, weird and complex. So I kept an open mind and thought: who knows? If it somehow primes the immune system in a way that lowers susceptibility to SARS-CoV2 and reduces the severity of disease progress, it would be worth it. It certainly wouldn’t be the first time something counterintuitive happened in immunology. It’s prescibed for Porphyria cutanea tarda, for Pete’s sake, and that’s a pretty strange disease, to say the least:


    With all the funds we’re spending for everything else, it seems like trying to answer that specific question clearly would be the proverbial drop in the bucket. Instead we’ve chosen to amplify and broadcast the very frightening, stay-away-at-all-costs narrative.

    • @Alex – thanks for this information, and for all of the information you provide on many of Phil’s topics. I have learned a lot, and you have an awesome writing style. Best, Paul

    • @Paul Beiser:

      I am long-winded, irrelevant and stupid – also self-referential, sniveling and bloviated. I’m an intellectually crippled reactionary right-wing moron and I know that nothing I say matters. I’m not qualified to comment authoritatively on any subject. I’m a white male heterosexual. I will be crushed and broken and ground into dust. But I’m very concerned about our country and the terrible dilemmas it faces. Thank you!

    • @Alex, you have an inspiring life story. You’re clearly a hard-working, independently thinking person who seeks out good information. Even if your business goes bankrupt because of this disaster, you can make something else work, I’m sure. You’re the sort of person that makes America great. I wish there were a lot more persons like you!!

    • Hey Alex….another fanboy here….Don’t always agree with your thinking but always look forward to you pushing my self-serving and/or confirmation bias around. Your non-confrontational, smart but breezy, approach is a model for my students!

  3. 2 different dosing regimens: Standard dosing of hydroxychloroquine for malaria prophylaxis is 400mg once a week. Dosing for COVID-19 treatment is 400mg once a day, with an initial dose of 800mg. COVID-19 treatment dose is more than 7 times the malaria prophylaxis dose.

  4. Plenty of youtube doctors saying its Zinc+HCQ that beats covid. They say Zinc blocks covid replication, while the HCQ just helps Zinc get into cells.

  5. The following irreverent post is certainly not intended as medical advice, but it may lift your spirits if you’re trying to avoid the Blue Meanies while locked down at home. Or: “When you accidentally take two pills instead of one.”

    In the town where I was born
    Came a plague CO-VID-19
    And we tried to live our lives
    Locked down in a quarantine

    Wish we’d taken hydroxycholoroquine!

    How much is too much hydroxychloroquine?


    And as someone points out in the comments for “Come Together”:
    1969: Come together, right now, over me.
    2020: Come together, but keep a distance of at least 6 feet, away from me.

  6. I take my HCQ with a Chlorox chaser every night – 400 mg washed down with a shot of the Chlorox. Works great.

    We all know Bill Gates and Big Pharma are hiding this MIRACLE DRUG COMBINATION from us.

  7. On May 8, “Hydroxychloroquine and azithromycin plus zinc vs hydroxychloroquine and azithromycin alone: outcomes in hospitalized COVID-19 patients” was uploaded to the Medrxiv pre-print server. This is an observational retrospective study done by NYU that includes hydroxychloroquine and zinc sulfate. It describes a 44% reduction in mortality. My limited understanding is that the hydroxychloroquine is an ionophore which allows the zinc to enter cells where it interferes with virus replication. All the other studies published to date do not use zinc sulfate. I also find it interesting that this has hardly been covered in the media. The only paper to cover it was the Daily Mail in the UK on May 13. The main advocate of this therapy, a Dr. Zelenko ( a GP, not at NYU), also claims that administration in the first five days will dramatically enhance efficacy.



  8. It wouldn’t matter if it was lethal. Trump would take it because like the rest of our rulers, he thinks he’s a god. A Roman emperor wouldn’t even make it to the Iowa primary.

  9. The cheap drug therapies like this are never going to be tried or approved by the Medical Drug cartels in the USA,. Too little drug $$ and no long hospitalizations or need for CDC and FDA help. Same issue with testing simple home therapy remedies like extra O2 + broad spectrum drugs + CPAP machines to improve immune response and avoid lung infections and patients need for hospitalization.

  10. A dozen doctors published in the New England Journal of Medicine on May 7 say it does nothing positive or negative for people who showed up at the hospital in respiratory distress. You need to be able to parse sentences like this if you want to critique their methods:


    “The nonparametric bootstrap method was used to obtain 95% pointwise confidence intervals for the inverse-probability-weighted Kaplan–Meier curves.” Take that, Joe Rogan!

    They conclude:

    “Clinical guidance at our medical center has been updated to remove the suggestion that patients with Covid-19 be treated with hydroxychloroquine. … The study results should not be taken to rule out either benefit or harm of hydroxychloroquine treatment, given the observational design and the 95% confidence interval, but the results do not support the use of hydroxychloroquine at present, outside randomized clinical trials testing its efficacy.”

    So they took it out service and said more research is needed. Not much about prophylaxis there at all. I still don’t think anyone’s studying it as preventive outside of a few people who are easy to portray as lunatics. The high doses mentioned elsewhere in this thread by @Gene Pasquil give me pause.

    • And why would they study it? What was the impetus for thinking this single drug, out of the tens of thousands of drugs on the market for everything under the sun from narcolepsy to restless leg, might be some overlooked, secret miracle cure that’s been right under our noses this whole time, yet is being stifled by big pharma, liberals, and researchers the world over? As far as I can tell, there never was a single credible reason for believing this drug was relevant in any way for treating or preventing COVID. Yet, it’s some kind of huge conspiracy and controversy because the vast majority of doctors and scientists refuse to put their faith behind a drug with zero evidence supporting its merits–not unlike a million other BS remedies. Me? I’m going to sniff some ground albino rhino horn and wear an amber necklace to bed while I rest my head on a $100 made in America pillow stuffed with chopped foam. Every day I’m becoming less shocked that Trump is the leader of the republican party.

    • @Senorpablo: The impetus was the handful of early studies and the people like Cahill at UCD. I should say that I don’t believe any of the conspiracies about HCQ being stifled by, Big Pharma, liberals, Bill Gates, or any of the others. To be honest I haven’t read any of them. It’s not my bag, and I’ll bet they’re loopier than Alex Jones on hash and whippets. I actually think Trump did himself a disservice by sounding so defensive in the press conference when he basically yelled at the reporter. He can really be his own worst enemy, but of course all of that goes back to the internal fights with Smart and BARDA.

      I think the chances of it helping as a prophylaxis are slim, but now that it’s such a huge question and fodder for so much conspiratorial thinking and political warfare, someone should design a study and try to answer it. Otherwise the nonsense will just keep spreading. Find 2,000 healthy uninfected (could we even do that in New York?) randomly give half of them HCQ+social distancing and the others placebo+social distancing and see what happens. Participants would have to be screened and accept the risk of taking a guess with the HCQ dose. After all the politics I don’t know whether any serious, credible group of researchers would want to make the effort. Now the topic itself is poisonous, and since the side effects are being fearmongered, who would sign up for it?

    • @Senorpablo: I’m also aware that there are no shortage of bad actors, foreign and domestic, pushing various conspiracies about HCQ and COVID through social media. Then we have the fact that getting a “study” listed on an clinicaltrials.gov appears to be about as easy as borrowing a username, password and organization name, all of 128 characters of data or so, and finding someone who knows how to write convincing mumbo jumbo. Boom! You’ve got a study listed on a U.S. Government website, like Dr. Eduardo Insignares Carrione, of the Genesis Foundation.
      He’s a real Renaissance man of medicne!


      I’ve trusted used car dealers in Newark, NJ more.

      “Does the A/C on this BMW work?”
      “It’s like new! Blows ice cold. We just got it back from the shop. Look, you can drive away for $1500 cash. But hurry, man because I gotta get my study on the effects of rhino horn on von Willibrand Disease published on the NIH website. I got some rhino horn right here, you want some with the car? Works great with the ladies, too.”

      My point is that at least if we had a credible result from researchers to work with, we’d be debating something other than whose conspiracy theory / ridiculous magical thinking penetrates farther. I don’t expect to convince you.

    • All this brouhaha about hydroxychloriquine perfectly illustrate the nonsensical thinking a large sector of the American people engage in. Thoughts and prayers, miracles and false prophets rather than reality, facts and science.

  11. Obama always said if you like your Hydroxychloroquine you can keep taking it. Toucan here one time went on an African safari and took the verboten. One side effect I remember was my dreams were very vivid and weird.

    • LinePilot: Thanks! They didn’t look at the magic of zinc plus hydroxychloroquine, though! (Or the magic of hydroxychloroquine plus healing crystal energy?) I thought it was zinc+hydroxychloroquine that was getting people excited.

    • Actually, now that I look at this, how is it relevant to the average person? They tested people who’d already been hospitalized with Covid-19. In other words, the study was done on people who were already mostly dead from the virus. So it answers the question “Can hydroxychloroquine resurrect a mostly dead person?” That’s not helpful if you’re trying to decide whether to pop some of these cheap generics (plus a few zinc pills from CVS) for prophylaxis.

    • @Philg: Nope, it doesn’t help the average person outside the hospital. They are screwed! 🙂 Unless and until there are a group of studies done by reputable authorities demonstrating safe prophylaxis, there’s no buy-in, no advice, no prescription, and most importantly — the FBI is watching. Woe betide the GP who starts writing lots of scripts for HCQ:


      “When the agent asked Staley how he had managed to get his hands on a drug in such high demand that people who need it, such as lupus patients, are having trouble finding the drug, he reportedly explained that he “got the last tank of hydroxychloroquine smuggled out of China on Sunday night.” A broker “tricked customs” by labeling the shipment as sweet potato extract, which was later confirmed by US Customs and Border Protection records.”

  12. I wouldn’t conflate the NYU paper that studied hydroxychloroquine taken with zinc with “crystal energy”. To my knowledge, though, it is the only reputable institution to have published anything on this. I agree that all the other sources are easily dismissed.

  13. 3308 Covid19 patients treated w/ HCQ/Azythomycine at French IHU in Marseille , only 18 deaths (0.5%) . https://www.mediterranee-infection.com/covid-19/ Think the reason this cheap effective treatment is being brutalized by big pharma is because it kills the need for the vaccines from the likes of Pill Gates & others who are counting on mandatory vaccines ; hence the vaccine peddlers need this Covid19 event to continue to kill people & keep up the anxiety and fear and lockdowns until their untested vaccines can be shoved into the sheeple

  14. It was effective in 2005 against SARS, no one would be surprised that it is has some effectiveness against COVID.


    Chloroquine is effective in preventing the spread of SARS CoV in cell culture. Favorable inhibition of virus spread was observed when the cells were either treated with chloroquine prior to or after SARS CoV infection. In addition, the indirect immunofluorescence assay described herein represents a simple and rapid method for screening SARS-CoV antiviral compounds.

  15. I took have been perplexed by the response to the sudden rage against hydroxychloroquine, as I was prescribed it by a doctor before setting off on a backpacking trip in Southeast Asia in 2015. When I got to the pharmacy, I balked at the $100 price tag and set off on my trip without it. I learned upon arriving in Thailand that I could easily buy it without a prescription at a local pharmacy for a mere $6 USD. I bought some, then learned that I didn’t need it at all as few of the places I would be visiting in my four month tour even had malaria due to the eradication of mosquitoes in virtually all tourist destinations. It wasn’t until I got to Myanmar that I thought I should take it, then learned from a fellow traveller (not American) to not bother as I would be given the exact same drug were I to *get* malaria, just in a higher amount.

    The whole fuss over trying to prove this generic drug ‘wrong’ or ‘dangerous’ has seemed extremely bizarre to me, given how cheap it is, and how widely used and available. If it doesn’t work, fair enough. (Although as others have pointed out, the one promising study from NYU shows it used in conjunction with zinc, which from the beginning has seemed like what, in addition to the price, gave the drug its appeal.) It seems like there is a determined effort to pooh pooh, dismiss, or excorciate anything that has been spoken by Trump or held up by “the right” as an alternative to extensive, unending lockdowns until a vaccine is magically created in unprecedented time (see also: endless articles shaming Sweden, Florida, Georgia, Professor Ioadinnis, anything that points out the actual risk to healthy people under the age of 60, etc.). As someone who is neither a Trump supporter nor a “right-winger”, I have been confused by the collective desire by the ‘mainstream media’ (and its loyal adherents) to so rapidly denounce anything that might present a more positive way forward, whether it’s a cheap drug & supplement combo used as a prophylactic or a strategic approach aimed at keeping the vulnerable safe while allowing children to continue going to school. It seems anything that has provided a small sliver of hope has been slammed for not advancing a narrrative of apocalyptic doomsday, and to that I ask, why? Have we really become so partisan than we can only have “hope” when our political party is in charge?

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