A lesson to be learned: the causes and the consequences of ivermectin use during the COVID-19 pandemic

This article was exclusively written for The European Sting by Ms. Ana Luiza Almeida Menezes and Ms. Emilly Mota Linhares, second year medical students in the Tiradentes University. They are affiliated with the International Federation of Medical Students Associations (IFMSA), cordial partner of The Sting. The opinions expressed in this piece belong strictly to the writers and do not necessarily reflect IFMSA’s view on the topic, nor The European Sting’s one.

The CoronaVirus pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has changed the way people live all over the world. Some symptoms include high temperature, continuous cough and loss or change to your sense of smell and taste. Besides that, it may cause fatigue, muscle pain and other debilitating damages to the heart, lungs and brain. According to Johns Hopkins University of Medicine, in late 2020, eighty-one percent of cases were categorized as mild, which symptomatic management at home and monitoring of clinical deterioration is recommended.

Due to lack of studies to determine the ideal type of treatment, many drugs were put into the spotlight as possible mitigators of coronavirus’ symptoms and long-term health effects. One of them is ivermectin, an inexpensive, already approved drug with a broad‐spectrum antiparasitic action, which has also been proven its antiviral potential in two RNA viruses, the West Nile virus, the Newcastle disease virus, and two DNA viruses, the pseudorabies virus and parvoviruses.

Ivermectin has become such a popular preventive drug in Latin American countries, like Peru, Bolivia and Guatemala, that scientists performing clinical trials struggled to recruit participants because so many were already taking it. Recent studies correlate the previously detected antiviral activity with its capability to act against the coronavirus, such as an in vitro study that presented the drug’s capacity of inhibition of SARS‐COV‐2 replication. Until october 2020, there were 40 clinical trials worldwide that  were testing the drug. 

The use of medical treatments must have a balance between risks and benefits as its main focus. The current evidences related to the effects of ivermectin in the combat against COVID-19 have low scientific quality due to the great risk of bias and the small amount of studies in humans.

In the recent researches using in vitro samples, it was noticed that ivermectin has shown effective action in combat against the multiplication of the virus. Moreover, the virus has as an effect the induction of an amplified immune response, causing a cytokine storm, responsible for the inflammation of lung tissue. Some studies indicate that ivermectin acts efficiently against the inflammatory downstream.

However, the findings suggest that ivermectin does not significantly affect the course of early COVID-19, some pharmacokinetic models showed that plasma total and unbound ivermectin levels do not reach the concentration that results in 50% of viral inhibition even for a dose level 10- 35 times higher than the approved doses.

In trials made with COVID-19 affected patients, there was a correlation between the use of ivermectin and a decreased number of deaths, especially in severe cases. Nevertheless, such studies showed multiple defects, specifically the small number of avaliated patients and not defined avaliation criteria,  making conclusive results impossible.

Lastly, it is important to emphasise that even though ivermectin has an antiviral action in the in vitro trials, its use in patients with COVID-19 is empirical and must be balanced by a responsable doctor. 

About the author

Ana Luiza Almeida Menezes and Emilly Mota Linhares are second year medical students in the Tiradentes University. They are members of International Federation of Medical Students Association in Brazil (IFMSA – Brazil) and strongly believe in the power of scientific research and the possibility of new pathways for COVID-19 treatment.