The problem with using it prophylatically is that it would need to be taken for the duration of the pandemic. This is problematic because of the adverse health effects of disturbing the zinc balance in your cells for an extended period of time. Look at some of the side effects and see if you think healthcare workers could do their jobs effectively while taking therapeutic doses of chloroquine.
Franck Touret et al. ( Antiviral Res. 2020 ) At least 16 different trials for SARS-CoV-2 already registered in the Chinese Clinical Trial Registry (ChiCTR2000029939, ChiCTR2000029935, ChiCTR2000029899, ChiCTR2000029898, ChiCTR2000029868, ChiCTR2000029837, ChiCTR2000029826, ChiCTR2000029803, ChiCTR2000029762, ChiCTR2000029761, ChiCTR2000029760, ChiCTR2000029741, ChiCTR2000029740, ChiCTR2000029609, ChiCTR2000029559, ChiCTR2000029542) propose to use chloroquine or hydroxychloroquine in the treatment of COVID-19 (Franck Touret et al. Antiviral Res. 2020 ) at the same time it has clinical trial registry for prevention study.
@ Erhan Tatar
Use of chloroquine for an extended period of time (for the duration of COVID-19) pandemic is not practical due to myriad of side-effects it may cause. However, use of Chloroquine or its less toxic derivative Hydroxychloroquine may be of benefit in people who are in quarantine after a contact with a confirmed COVID-19 case.
We will have to wait for the initial results of the WHO supervised mega-trial "SOLIDARITY" before we can definitely have a solid proof of its benefits vs risks.
https://www.sciencemag.org/news/2020/03/who-launches-global-megatrial-four-most-promising-coronavirus-treatments
'' Insights from nanomedicine into chloroquine efficacy against COVID-19'' ( 10.1038/s41565-020-0674-9. ) should be read...
Article Acquired Long QT Syndrome: A Review of the Literature
This review discusses the points I outline below.
Several medications that have been recommended for the treatment of Covid-19 are associated with prolongation of the QTc interval and therefore torsade de pointes and sudden cardiac death.
The evidence of the potential benefit of chloroquine and hydroxychloroquine in the treatment of Covid-19 is increasing.
Other medications which may be used in this cohort include the macrolide antibiotics (e.g. azithromycin). These can also prolong the QTc interval. Administering several medications that may prolong the QT interval is associated with a high risk of complications.
In medicine risks and benefits must be balanced. Safety netting is important whenever there is a great potential benefit but also a very significant risk. In that context QTc intervals, renal and liver function must be monitored closely in patients treated with chloroquine and or macrolides. They should probably not be started if the baseline QTc is more than 450 ms. It should probably be stopped if the QTc increases 25% above baseline. It should definitely be stopped if QTc is above 500 ms. This is an evolving situation and recommendations may change as the potential risks and benefits become clearer.
Beta-blockade is used in the treatment of congenital and acquired long QT syndrome, so may be beneficial in this setting.
There are many professionals in our hospital infected and the authorities have distributed chloroquine to use 400mg weekly. What do you think of this dose?
Unfortunately, the prophylaxis scheme for hydroxychloroquine has not yet been scientificly recommended
The manus entitled ''Finding the dose for hydroxychloroquine prophylaxis for COVID-19; the desperate search for effectiveness.'' should be read.
For more answers to your question here is an article published by the Lancet: https://www.thelancet.com/action/showPdf?pii=S1473-3099%2820%2930296-6