In a March 27, 2020 Tech Startups article about a controversial study about the treatement of COVID-19 with the drugs Chloroquine and Hydroxychloroquine they quote a paper as saying:

Chloroquine and hydroxychloroquine are extremely well-known drugs which have already been prescribed to billions of people.

Is that true, have billions of people been prescribed these (anti-malaria) drugs?

  • 3
    Near miss reference that maybe someone can use: US alone, 10 years alone, Hydrocychloroquine alone: on the order of 45+ million prescriptions.
    – Oddthinking
    Apr 1, 2020 at 10:46
  • 2
    Another near miss: Executive summary to book makes unreferenced claim that Chloroquine has cured billions of malarial episodes.
    – Oddthinking
    Apr 1, 2020 at 10:48
  • 1
    So what part of this do you doubt, the "billions" or just that's been widely prescribed? Apr 1, 2020 at 19:30
  • 1
    I know in India there were huge number of people given quinine long time ago because of its anti-malaria properties. The British drink gin-and-tonic has evolved because of tonic having quinine in them. I am not sure if this thing is same/similar but if it is quinine then yes it is well known
    – Tanmoy
    Apr 2, 2020 at 1:03
  • 2
    I suspect this is false because of the word "prescribed". In my experience (close to a year of travel) chloroquine was an over the counter drug in the parts of the world where it was needed for malaria prophylaxis and treatment. This was at the very end of it's effectiveness in the old world so it's unlikely there were a substantial number of prescriptions in those areas. I would be shocked if there weren't billions of person-years of use, though. Apr 2, 2020 at 4:03

1 Answer 1


I haven't found direct stats on this, but given that according to the UN, in 2015 alone

Funding for malaria programmes has reached unprecedented levels. [...] Last year 88% of the 214 million cases [...] occurred in the WHO African region. [...] While more than 1 billion mosquito nets have been distributed in sub-Saharan Africa since 2000, there are doubts about whether people are using them properly.

So if you have 200 million cases per year, and these are prescribed a drug, in 5 years you'd get that billion prescriptions, although they might be the same individuals being prescribed... year after year. So YMMV. I've included the quote on nets distributed for comparison with another non-pharmaceutical anti-malaria intervention/prevention effort that has reached billions.

As hinted to me by @Taladris below, one also needs to consider that the malaria pathogen developed/develops resistance to drugs in this family. So there have been changes to the recommended treatment in various parts of the world, which make the claim less likely to be true. The following quote is from a 2002 source, and is mostly qualitative in nature, but should be indicative of the additional difficulty in evaluating the claim (about these two specific drugs), in the absence of precise statistics about them in particular/isolation:

For example, CQ is still the recommended first-line treatment for P. falciparum in much of Africa, despite the high prevalence of CRPF [Chloroquine-resistant P. falciparum]. [...]

Drug resistance is not an all-or-nothing phenomenon. In any given area, a wide range of parasitological responses can be found, from complete sensitivity to high-level resistance (see Table 3-4). In general, malaria parasites in western sub-Saharan Africa are less resistant to drugs like CQ and SP than malaria parasites in eastern or southern Africa. [...]

The policy response to increasing evidence of antimalarial drug resistance has been variable as well. In parts of East Africa, parasitological resistance to CQ is very high, with 80 to 90 percent of P. falciparum infections being moderately to highly resistant (Bloland et al., 1993). In response to these high rates of resistance, Malawi switched from CQ to SP for first-line therapy for P. falciparum in 1993. A number of countries in eastern and southern Africa (including Tanzania, Kenya, Democratic Republic of Congo, Rwanda, Uganda, Ethiopia) have made similar policy changes to SP alone or in combination (with either CQ or amodiaquine) on a national or provincial/district level. After a long period of disinclination to change treatment policies, many more countries in sub-Saharan Africa are now reevaluating their national treatment guidelines and considering policy changes to locally effective regimens. Although the drugs being used differ, similar efforts are under way in the Amazon region and Southeast Asia.

  • Thanks, yes I agree with your comment that prescribed to billions of people is indeed different from the number of prescriptions. I don't know whether the same people keep getting the drug, or whether there is a large turnover, but I would have guessed that the malaria areas stay the same, i.e. that chloroquine and hydroxychloroquine users would be recurrent. The entire Africa currently has 1.2G people, and was far less populous (and probably less medicated too) in the past, so not intuitive how to reach billions of users. Apr 1, 2020 at 19:44
  • 3
    @Shadur: I don't think the quote in the question is implying "1) in response to COVID19", merely that even if the efficacy for COVID19 / SARS-COV-2 is not known, the safety is very well-established (as effects have been observed in a huge number of people).
    – Ben Voigt
    Apr 8, 2020 at 19:23
  • 4
    -1. I lived in Senegal for a few months a decade ago and I seriously doubt that the majority of people infected by malaria in Africa get a treatment. There is a reason why malaria is one of the most deadly diseases in the world. Also, chloroquine is not used anymore in Western Africa since the virus became resistant. Other drugs (Lariam, Malarone, doxycycline) are used by travelers, militaries and NGOs in these areas.
    – Taladris
    Apr 11, 2020 at 1:23
  • 1
    @Taladris: interesting. Please consider writing your own answer if you also know of any statistics of % of malaria-ill people who do get treated with this drug/drugs. I was indeed assuming that they get widely treated given how cheap these drugs are (in Africa) $0.04 / dose, as reported. Apr 11, 2020 at 1:26
  • 1
    @Taladris: I've added something about drug resistance and change in drugs to the answer, although it is somewhat vague (and the source fairly dated). Apr 11, 2020 at 1:54

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .