A randomised clinical trial in Colombia for ivermectin treatment in mild COVID returned disappointing results.
An anti-parasitic normally used for livestock, ivermectin has gathered considerable attention as a possible COVID treatment in recent months, especially locally, with stocks containing the product depleted in the last month. There are no ivermectin-containing products in South Africa for human use. The South African Health Products Regulatory Authority is of the view that the evidence for ivermectin is currently inconclusive.
“To our knowledge, preliminary reports of other randomized trials of ivermectin as treatment for COVID-19 with positive results have not yet been published in peer-reviewed journals,” the researchers wrote.
The randomised, double-blind, single-center study took place from July 15 to December 21, 2020. Patients were assigned to either receive an oral dose of 300 μg/kg of body weight per day of ivermectin or placebo, for five days. Follow-up took place on days 2, 5, 8, 11, 15, and 21. The primary trial outcome was resolution of symptoms within 21 days.
However, the study was not without its share of problems. The initial primary outcome was time from randomisation until worsening of symptoms by two points on an ordinal scale, but few patients reached this endpoint in the expected time. This meant the sample size needed to maintain sufficient power was “unattainable.” To accommodate this, the primary endpoint was changed to time from randomisation to symptom resolution by day 21, retaining the original sample size.
To make matters worse, a labelling error occurred, where ivermectin was mistakenly given to all patients from September 29 to October 15, so the protocol was amended, with these patients excluded from the primary analysis. The researchers then recruited more patients to retain the originally calculated study power.
Despite these problems, the researchers said the findings remained valid within the confines of its other limitations. Limitations to the study, the researchers said, included that it was not conducted or completed according to the original design; that it may have been underpowered to detect a smaller, clinically meaningful reduction in the primary endpoint; and virological assessments were not included, only clinical characteristics.
Larger trials would be needed “to understand the effects of ivermectin on other clinically relevant outcomes,” concluded the researchers.
Source: MedPage Today
Journal information: López-Medina E, et al “Effect of Ivermectin on Time to Resolution of Symptoms Among Adults With Mild COVID-19 — A Randomized Clinical Trial” JAMA 2021; DOI: 10.1001/jama.2031.3071.
