Ivermectin in combination with doxycycline for treating COVID-19 symptoms: a randomized trial

J Int Med Res. 2021 May;49(5):3000605211013550. doi: 10.1177/03000605211013550.


Objective: We evaluated whether ivermectin combined with doxycycline reduced the clinical recovery time in adults with COVID-19 infection.

Methods: This was a randomized, blinded, placebo-controlled trial in patients with mild-to-moderate COVID-19 symptoms randomly assigned to treatment (n = 200) and placebo (n = 200) groups. The primary outcome was duration from treatment to clinical recovery. Secondary outcomes were disease progression and persistent COVID-19 positivity by RT-PCR.

Results: Among 556 screened patients, 400 were enrolled and 363 completed follow-up. The mean patient age was 40 years, and 59% were men. The median recovery time was 7 (4-10, treatment group) and 9 (5-12, placebo group) days (hazard ratio, 0.73; 95% confidence interval, 0.60-0.90). The number of patients with a ≤7-day recovery was 61% (treatment group) and 44% (placebo groups) (hazard ratio, 0.06; 95% confidence interval, 0.04-0.09). The proportion of patients who remained RT-PCR positive on day 14 and whose disease did not progress was significantly lower in the treatment group than in the placebo group.

Conclusions: Patients with mild-to-moderate COVID-19 infection treated with ivermectin plus doxycycline recovered earlier, were less likely to progress to more serious disease, and were more likely to be COVID-19 negative by RT-PCR on day 14.

Trial registration: ClinicalTrials.gov Identifier: NCT04523831.

Data repository id: Dryad. doi:10.5061/dryad.qjq2bvqf6.

Keywords: COVID-19; Ivermectin; doxycycline; infection; recovery time; reverse transcription polymerase chain reaction.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • COVID-19*
  • Doxycycline / therapeutic use
  • Female
  • Humans
  • Ivermectin* / therapeutic use
  • Male
  • SARS-CoV-2
  • Treatment Outcome


  • Ivermectin
  • Doxycycline

Associated data

  • ClinicalTrials.gov/NCT04523831