Hydroxychloroquine Pre-Exposure Prophylaxis for COVID-19 Among Healthcare Workers: Initial Experience from India

Abstract

Background: Hydroxychloroquine(HCQ) prophylaxis has been proposed for coronavirus disease-2019(COVID-19). This prospective observational study was conducted to assess the safety and efficacy of HCQ for pre-exposure prophylaxis.

Methods: The study was conducted at All India Institute of Medical Sciences, a tertiary care hospital in New Delhi, India with dedicated COVID-19 care facilities. Asymptomatic healthcare workers(HCWs) were recruited and grouped into two based on whether they were voluntarily taking HCQ as per national guidelines. Side effects in HCQ group were graded in accordance with NCI-CTCAE version 5·0. At 3-6 weeks follow-up, groups were compared for COVID-19 exposure, symptoms development, and SARS-CoV-2 RT-PCR results. Primary outcome was incidence of adverse effects, with secondary outcome being efficacy in preventing COVID-19.

Findings: Among 334 participants recruited, 202(60·5%) were males and the mean age was 31±6·5 years. HCQ prophylaxis was initiated by 248(74·2%); those working in COVID-19 care areas were more likely to initiate voluntary prophylaxis. After loading dose, 7(2·8%) reported grade 2, and 1(0·4%) grade 3 adverse effects. Discontinuation of HCQ due to side effects was reported in 11(4·4%) participants. Electrocardiogram was done in 50(20·2%) participants on HCQ, no abnormalities were noted. A total of 68(27·4%) among those taking and 49(56·9%) among those not taking HCQ were tested for SARS-CoV-2 due to influenza-like symptoms or significant exposure. Among all participants, 7(2·2%, 95% CI 0·6-3·9) developed COVID-19 at median 5 weeks follow-up. In the group taking HCQ, 2(0·8%) tested positive compared to 5(5·8%) in the group not taking HCQ (p=0·013). Odds ratio with HCQ intake was 0·13(95% CI 0·02-0·85, p=0·03) and the number needed to treat was 26.

Interpretation: HCQ is safe at the recommended dose for pre-exposure prophylaxis of COVID-19. HCQ chemoprophylaxis may decrease COVID-19 incidence; randomized controlled trial is required to validate findings.

Funding Statement: All India Institute of Medical Sciences intramural fund.

Declaration of Interests: All authors declare that there is no conflict of competing interest. Dr. Soneja has nothing to disclose.

Ethics Approval Statement: Ethical clearance was obtained from the Institute Ethics Committee.

Keywords: Hydroxychloroquine; COVID-19; SARS CoV-2; Pre-exposure Prophylaxis; Healthcare Workers; India