Post Exposure Prophylaxis with Hydroxychloroquine (HCQ) for the Prevention of COVID-19, a Myth or a Reality? The PEP-CQ Study

Dhibar, Dr. Deba Prasad; Arora, Dr. Navneet; Kakkar, Dr. Arpit; Singla, Dr. Neeraj; Mohindra, Dr. Ritin; Suri, Dr. Vikas; Bhalla, Dr. Ashish; Sharma, Dr. Navneet; Singh, Dr. Mini P; Prakash, Dr. Ajay; PVM, Dr. Lakshmi; Medhi, Dr. Bikash

BACK GROUND: Since the arrival of the COVID-19 pandemic many available drugs have been tried for the treatment or prevention of COVID-19 with limited success or failure. The household direct contacts of the COVID-19 patients are at highest risk for SARS-CoV-2 infection. Hydroxychloroquine (HCQ) has been tried against COVID-19 in the view of its in-vitro virucidal action against SARS-CoV-2, but the role of HCQ as post exposure prophylaxis (PEP) is still inconclusive and evolving. METHOD: In this open label control clinical trial asymptomatic individual who had direct contact with laboratory confirmed COVID-19 cases or had undertaken international travel in last 2 weeks were given the option for taking HCQ prophylaxis and assigned into PEP (N=132) and control groups (N=185). The PEP group received tablet HCQ 800 mg on day one followed by 400 mg once weekly for 3 weeks. Both the groups received standard care of therapy in the form of home quarantine for 2 weeks along with social distancing and personal hygiene and followed up for 4 weeks for new onset COVID-19. RESULTS: Total 50 out of 317 participants (15.8%) had new onset COVID-19. The incidence of COVID-19 was significantly (p=0.033) lower in PEP group [N=14 out of 132, (10.6%)] as compared to the control group [N=36 out of 185, (19.4%)]. Total absolute risk reduction for the incidence of COVID-19 was -8.8% points. The number needed to treat (NNT) to prevent occurrence of one case of COVID-19 was 12. The overall relative risk was 0.59 (95% confidence interval, 0.33 to 1.05). The compliance was good and most common ADR was epigastric discomfort with burning sensation, reported by 3 participants and no serious ADR was noted. CONCLUSION: PEP with HCQ has the potential for the prevention of COVID-19 in at-risk individuals. Till definitive therapy is available, continuing PEP with HCQ may be considered in suitable at-risk individuals for the prevention of COVID-19, as endorsed by many national/international health authorities. The present study will encourage the researchers around the globe to reconsider further randomized clinical trials with larger sample size for better evaluation of HCQ as PEP for the prevention of COVID-19. TRIAL REGISTRATION: clinicaltrials.gov PRS ID: CT04408456