Hydroxychloroquine as Prophylaxis for COVID-19: A Review

Area of Science:

• * Infectious Diseases
• * Pharmacology
• * Drug Repurposing

Background:

• * The COVID-19 pandemic spurred a search for effective prophylactic agents.
• * Hydroxychloroquine (HCQ) emerged as a controversial drug candidate for COVID-19 prevention.
• * Drug repositioning offers advantages like known toxicity profiles but faces funding challenges for large trials.

Purpose of the Study:

• * To conduct a comprehensive review of hydroxychloroquine's (HCQ) potential prophylactic role in COVID-19.
• * To objectively assess available scientific and clinical data on HCQ for disease prevention.
• * To analyze ongoing clinical trials to identify evidence supporting HCQ's prophylactic use.

Main Methods:

• * Literature review of preclinical and clinical data on hydroxychloroquine (HCQ) for COVID-19 prophylaxis.
• * Examination of ongoing clinical trials from major repositories.
• * Analysis of trial designs, including randomization, phase, comparators, sample size, participant demographics (healthcare workers), HCQ dosing schedules, and treatment durations.

Main Results:

• * Substantial preclinical data exists for hydroxychloroquine (HCQ), but clinical data remains limited.
• * Seventy-seven clinical trials (CTs) investigating HCQ for COVID-19 prophylaxis were identified, indicating no established standard of care.
• * Most CTs are randomized (92%), phase 2/3 (53%), involve up to 1,000 subjects (62%), and recruit healthcare workers (71%). Various HCQ dosing regimens and durations are being tested.

Conclusions:

• * The translational impact of in vitro findings for hydroxychloroquine (HCQ) requires further clinical validation.
• * The large number and varied designs of ongoing clinical trials highlight the need for standardized protocols.
• * Rigorous methodological approaches in prospective randomized clinical trials are crucial to ascertain the efficacy of prophylactic hydroxychloroquine (HCQ) in preventing COVID-19.