Doxycycline is a safe alternative to Hydroxychloroquine + Azithromycin to prevent clinical worsening and hospitalization in mild COVID-19 patients: An open label randomized clinical trial (DOXYCOV)

Objective: We aimed to compare the safety and efficacy of a doxycycline-based regimen against the national standard guidelines (Hydroxychloroquine plus Azithromycin) for the treatment of mild symptomatic COVID-19. Methods: We conducted an open-label, randomized, non-inferiority trial, in Cameroon comparing Doxycycline 100mg, twice daily for 7 days versus Hydroxychloroquine, 400 mg daily for 5 days and Azithromycin 500mg at day 1 and 250mg from day 2 through 5, in mild COVID-19 patients. Clinical improvement, biological parameters and adverse events were assessed. The primary outcome was the proportion of clinical cure at day 3, 10 and 30. Non-inferiority was determined by the clinical cure rate between protocols with a 20 percentage points margin. Results: 194 participants underwent randomization and were treated with Doxycycline (n=97) or Hydroxychloroquine-Azithromycin (n=97). At day 3, 74/92 (80.4%) participants on Doxycycline versus 77/95 (81.1%) on Hydroxychloroquine-Azithromycin -based protocols were asymptomatic (p=0.91). At day 10, 88/92 (95.7%) participants on Doxycycline versus 93/95 (97.9%) on Hydroxychloroquine-Azithromycin were asymptomatic (p=0.44). At day 30 all participants were asymptomatic. SARS-CoV2 PCR was negative at Day 10 in 60/92 (65.2%) participants allocated to Doxycycline and 63/95 (66.3%) participants allocated to Hydroxychloroquine-Azithromycin. None of the participants were admitted for worsening of the disease after treatment initiation. Conclusion: Doxycycline 100 mg twice daily for 7 days is as effective and safe as Hydroxychloroquine-Azithromycin, for preventing clinical worsening of mild symptomatic or asymptomatic COVID-19, and achieving virological suppression