key: cord-0759020-s1hmhupe
authors: Simova, Iana; Vekov, Toni; Krasnaliev, Jordan; Kornovski, Vladimir; Bozhinov, Plamen
title: Hydroxychloroquine for prophylaxis and treatment of COVID-19 in health care workers
date: 2020-11-12
journal: New Microbes New Infect
DOI: 10.1016/j.nmni.2020.100813
sha: 13d711295ae2629a8c0e886262a57c0cca175fe1
doc_id: 759020
cord_uid: s1hmhupe

Hydroxychloroquine (HCQ) exerts antiviral effects through several mechanisms. Our initial experience suggests that HCQ could be used for prophylaxis of COVID-19 infection in health care workers (HCW) and could help to control the virus in the early disease stages. We suggest a prophylactic strategy with HCQ for autumn-winter-spring 2020-2021.

Providing adequate health care is vitally important during the COVID-19 pandemic to keep morbidity and mortality low. Health care workers (HCW) are key guarantees for this process, and they must feel safe and adequately protected, which includes reliable prophylactic measures (1) .

Hydroxychloroquine (HCQ) could exert antiviral effects, essential for prophylaxis and early treatment of COVID-19, through several mechanisms: 1) endosomal pH increase, which inhibits SARS-CoV-2 entry through the host cells' membranes; 2) inhibition of ACE2 cell receptor glycosylation, which impedes SARS-CoV-2-receptor binding; 3) blocking the transport of SARS-CoV-2 from early endosomes to endolysosomes, which prevents the release of viral genome; 4) immunomodulation; 5) limiting the post-viral cytokine-storm syndrome (2, 3).

We share the experience of the Bulgarian Cardiac Institute (BCI) regarding the use of HCQ for prophylaxis and treatment of COVID-19 in HCW.

BCI comprises seven hospitals and eight medical centers, with around 1200 HCW, covering more than two-thirds of Bulgarian territory.

Since March 2020, many of our employees were in close contact with COVID-19 cases. We offered prophylaxis with HCQ 200 mg qd for 14 days to 204 of them. 76.4% of the group (156 HCW) used HCQ and neither of them presented with COVID-19 symptoms. Unfortunately, out of the rest 48 HCW that refused HCQ prophylaxis, three developed symptoms and tested positive for COVID-19.

During the last seven months, 38 HCW at BCI tested positive for COVID-19, half of them symptomatic. We suggested the following treatment regimen as an early home-based therapy for them: azithromycin 500 mg qd; HCQ 200 mg tid and Zn up to 50 mg qd for 14 days. 33 (86.8%) of them undertook this treatment, with symptoms abolishing between 2 nd and 4 th day, none of them requiring hospitalization and with a negative PCR on 14 th day for all. The rest five HCW (13.2%) employed alternative treatment regimens, none of them including HCQ. Three of them still tested positive at 14 th day and two of them required hospitalization.

All HCW (191) treated with HCQ, took Zn as well. We performed ECGs at baseline, on 3 rd and 5 th day of HCQ-treatment with QTc measurement. Baseline QTc was 412 ± 23 ms, 3 rd day QTc: 429 ± 27 ms, and 5 th day QTc: 427 ± 31 ms, p>0.05 for all comparisons. We registered QTc increase ≥60 ms in five HCW. QTc increased >470 ms in one male and >480 ms in three female HCW. In all these occasions HCQ was stopped. We did not register any rhythm disorders.

A possible drawback of HCQ prophylaxis is the risk for selecting resistant microorganisms, as has been described for Plasmodium spp. However, at present we do not have any data about SARS-CoV-2 resistance to HCQ (4).

In conclusion, our experience at BCI suggests that HCQ could possibly provide protection against infection with SARS-CoV-2 (prophylaxis), and could, if used early, help control the COVID-19 infection (treatment).

Based on this experience, we at BCI adopted a new prophylactic strategy for HCW starting from the 2 nd half of October 2020. This includes alternative months of HCQ intake (200 mg qd) and months without therapy. We are planning to continue this prophylaxis regimen throughout the autumn, winter, and spring months.

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Hydroxychloroquine is effective, and consistently so used early, for Covid-19: A systematic review

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