Dear Editor,

Ivermectin is an anthelmintic agent with the ability to inhibit the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in cell cultures.

Due to the extremely deadly nature of this disease many clinicians are desperately trying to save lives by using agents which attack the virus at different stages of the life cycle of the virus. The use of many agents such as Ivermectin was based on preclinical research in vitro (not in humans). For human use and effectiveness it had to be used in too large a dose (100 times higher than the safe dose that is approved for use in humans). There was a warning issued in April 2020 by the United States Food and Drug Administration (FDA) that the use of Ivermectin in humans for COVID-19 treatment was not allowed.

The latest information from the Centres for Disease Control and Prevention (CDC) on February 11, 2021 still does not support the use of Ivermectin to treat COVID-19.

Ivermectin has been shown to inhibit the replication of SARS-CoV-2 in cell cultures. However, pharmacokinetic and pharmacodynamic studies suggest that achieving the plasma concentrations necessary for the antiviral efficacy detected in vitro would require administration of doses up to 100-fold higher than those approved for use in humans.

The revised guidelines and the results of several randomised trials and retrospective cohort studies of Ivermectin used in patients with COVID-19 have been published in peer-reviewed journals or have been made available as manuscripts ahead of peer review. Some clinical studies showed no benefits or worsening of the disease after Ivermectin use, whereas others reported shorter time to resolution of disease manifestations that were attributed to COVID-19, greater reduction in inflammatory marker levels, shorter time to viral clearance, or lower mortality rates in patients who received Ivermectin than in patients who received comparator drugs or placebo.

Most of these studies contain incomplete information and also had important methodological limitations, which made it difficult to excluded common causes of bias, and which would render a trial flawed.

The limitations identified include:

* the sample size of most of the trials was small;

* various doses and schedules of Ivermectin were used;

* some of the randomised controlled trials were open-label studies in which neither the participants nor the investigators were blinded to the treatment arms;

* patients received various concomitant medications (for example doxycycline, hydroxychloroquine, azithromycin, zinc, corticosteroids) in addition to Ivermectin or the comparator drug, which confounded the assessment of the efficacy or safety of Ivermectin;

* the severity of COVID-19 in the study participants was not always well described; and

* the study outcome measures were not always clearly defined.

Due to the important limitations of these studies, the expert panel was prevented from arriving at definitive conclusions on the clinical efficacy of Ivermectin for the treatment of COVID-19.

Pharmacists utilise treatments or try to promote only drugs that have been approved for use by bodies like the FDA, CDC, and European bodies. In Jamaica we abide by the guidelines of the Ministry of Health and Wellness, which advises us of safe, evidence-based approaches to use.

Dr Winsome Christie
President
Pharmaceutical Society of Jamaica