A Randomized Controlled Trial of Hydroxychloroquine as Prophylaxis for COVID-19 among Health Care Providers

Although there is a growing consensus that hydroxychloroquine may not be effective in the treatment of COVID-19 patients, there is still little high-quality evidence about the prophylactic effects of this medication. In this study, we aimed to evaluate the efficiency of hydroxychloroquine in preventing COVID-19 infection among healthcare workers.

In this clinical trial, 90 healthcare providers from two referral hospitals of COVID-19 were divided into the hydroxychloroquine group (400 mg/week for eight weeks) and the routine-care group. Serum CRP levels and the frequency of T-helper (CD4+ cells) and T-cytotoxic (CD8+ cells) were assessed at the beginning and end of the study. The groups were compared in terms of White Blood cells (WBCs), polymorph nuclear cells (PMNs), lymphocytes (LYM), hemoglobin (Hb), and platelets (Plt.).

The results revealed no significant differences between the two groups in terms of WBC, PMN, LYM, Hb, Plt., CD4, and CD8. The mean difference of the CD4:CD8 ratio showed a significantly higher decrease (P=0.05) in hydroxychloroquine group than in the control group (0.18 vs. 0.02). The incidence of COVID-19 was 15% (95%CI: 12-18%) in the control group and 10% (95%CI: 8-12%) in the intervention group; however, no significant difference was observed between the two groups in this regard (P=0.45).

Our study findings boost an increasing level of evidence that hydroxychloroquine is not an effective prophylactic medication against COVID-19 and might even exacerbate the profile of pandemic containment efforts by adding more pain to patients’ life and healthcare services.