Read on Twitter
A lot of attention has been focused on studies using chloroquine and other drugs to treat #covid19 patients. But there are also numerous trials that are aiming to use these drugs to *prevent* the disease. Story is here. Short thread. https://www.sciencemag.org/news/2020/04/trials-drugs-prevent-coronavirus-infection-begin-health-care-workers
Why is this important? As long as there is no vaccine available to prevent #covid19 any drug that could be used to prevent the disease would be a huge boon. It could help lower the burden on hospitals, protect vulnerable populations and keep the health care system functioning.
It could be a particularly important tool to help fight #covid19 in poorer countries. As Nicholas White told me: “In fragile health care systems, if you start knocking out a few nurses and doctors, the whole thing can collapse.”
One approach is post-exposure prophylaxis: PEP. In that strategy, people who have had contact with a known #Covid19 case would take drugs for a short period of time in the hope of preventing the disease and stopping transmission.
One trial led by @oriolmitja started in Barcelona in March. It hopes to show that people with known exposure to #COVID19 patients - health care workers, nursing home residents or household contacts - can be protected by taking hydroxychloroquine for 4 days.
Procedure is reminiscent of Ebola ring vaccination trial: The contacts of a new #covid19 case (more than 15 minutes in previous 5 days) are identified and all of them together are randomised to receive either hydroxychloroquine or nothing (no placebo in this trial).
Researchers will then compare how many symptomatic #covid19 cases occur in the two groups after 14 days. Results from the first 1000 contacts could be released next week. (Trial is here: https://clinicaltrials.gov/ct2/show/NCT04304053)
There are many similar #covid19 PEP studies that are starting up, for instance in
New York: https://www.clinicaltrials.gov/ct2/show/NCT04318444
Minnesota: https://covidpep.umn.edu
Washington: https://depts.washington.edu/covid19pep/about/
New York: https://www.clinicaltrials.gov/ct2/show/NCT04318444
Minnesota: https://covidpep.umn.edu
Washington: https://depts.washington.edu/covid19pep/about/
The other approach is Pre-exposure prophylaxis: PrEP. This would mostly be aimed at health-care workers, who would take a drug for months to reduce their risk of being infected.
Huge PrEP trial led by Nicholas White should start this month. Idea is to treat 40,000 health-care workers in Asia, Europe and Africa with hydroxychloroquine, chloroquine or placebo for 3 months and compare number of symptomatic #covid19 infections. ( https://clinicaltrials.gov/ct2/show/NCT04303507)
Some countries (incl. India) have already recommended chloroquine/hydroxychloroquine for prophylaxis.
Bad idea because:
1. we don’t know if it works
2. it has side effects (incl. possibly serious heart problems)
3. it may increase infection risk by giving false sense of security
Bad idea because:
1. we don’t know if it works
2. it has side effects (incl. possibly serious heart problems)
3. it may increase infection risk by giving false sense of security
4. it drains supply for patients who need this drug to treat lupus, etc.
5. it means drug cannot be studied there. (White now has to exclude India from his study, for instance.) That’s bad because the world really needs these trials to get a clear answer on what works.
5. it means drug cannot be studied there. (White now has to exclude India from his study, for instance.) That’s bad because the world really needs these trials to get a clear answer on what works.
Last point: So far there is no good evidence that #chloroquine or #hydroxychloroquine is effective against #covid19. One reason may be that drugs are given to patients too late to make a difference. If true, PEP and PrEP trials may be our best shot at getting a definitive answer.
