Ivermectin is a Food and Drug Administration (FDA) approved anti parasitic drug. Review journal, “Trends in Parasitology” describes its mechanism of action as interfering with nerve and muscle function of invertebrate parasites (like insects and worms) by binding and blocking ion channels that play a role in the physiological processes of these muscle cell’s movements.
Ion channels are specialized proteins through which ions – either a particle, atom or molecule – can pass through.
Ivermectin pushes these channels open increasing the flow of ions – hyperpolarizing aka negatively charging the cell membranes which increases the stimulus or the charge it needs for movement, consequently paralyzing the tissue when it does not get enough charge and eventually killing the invertebrate.
While these channels are present in the brain and spinal cords of mammals (including humans), the drug does not cross their blood-brain barrier, which is a membrance that protects the brain by disallowing toxic substances to flow through while letting vital nutrients pass. Ivermectin is not allowed to pass through this barrier thus it can only target the parasites present in the body and not the body itself.
The 11th edition of the Pharmacological basis of therapeutics by Gilman and Goodman details common side effects including fever, itching and skin rash. The adverse effect of the drug on the other hand is neurotoxicity, which is basically saying that it’s a substance that may be toxic to the brain and causes effects such as depression, cognitive impairment, motor and sensory loss, central nervous system depression among others.
Gilman and Goodman additionally states that while the drug does not cross the blood brain barrier, there is risk that it may actually pass through when it is administered along other drugs in which their mechanism of action loosens the permeability of this blood brain barrier. Examples of these medications are some statins, calcium channel blockers (Amlodipine) lidocaine, benzodiazepines and glucocorticoids like dexamethasone.
On treating COVID-19, based on an article published in the Journal of Antibiotics last Sept 2020, in vitro or laboratory experiments showed that ivermectin has antiviral effects against SARS-COV-2. Subsequent studies published in the Turkish journal of Medical sciences found that ivermectin could inhibit the replication of SARS-COV-2 in monkey kidney cells grown in a lab. Based on this information, when it was translated to a human dosage it exceeds the maximum approved and safely achievable use for humans, which means for the antiviral effect to work, theoretically one needs to overdose on a large amount of ivermectin and this ofcourse brings more harm than good.
On January 2021 results of a randomized controlled trial (RCT) of 24 patients with non-severe COVID-19 and no risk factors found no difference in PCR-positive nasal swabs nor viral load between patients who received ivermectin and those given placebo, thus failing the primary outcome of the study, which means there’s no reason to proceed with further clinical trials as it is evident that ivermectin has no effect on COVID-19, the real thing, and not the one’s grown on the lab and tested on monkey cells.
On February 2021, Merck, the company from which the drug originated, released a statement that said there is no good evidence for ivermectin’s use against COVID-19, and that attempting such may be unsafe.
In March 2021, both the FDA and the European Medicines Agency (EMA) issued guidance that ivermectin should not be used to treat or prevent COVID-19.
Ivermectin continues the trend of drugs Investigated for the treatment of COVID-19 since 2020 but subsequently proven ineffective, and possibly dangerous, in the context of people with COVID-19 (like hydroxychloriquine). Surgical Oncologist David Gorski has stated that the narrative of ivermectin as a “miracle cure” for COVID-19 is a “metastasized” version of a similar conspiracy theory around the drug hydroxychloroquine, in which unspecified powers are thought to be suppressing news of the drug’s effectiveness for their own malign purposes.
Ivermectin is not a bad drug, in fact it is one of the best drugs being used to treat against worms and other parasites infecting both humans and animals. While containing a small portion of anti-viral properties in a controlled laboratory setting, it fails to replicate this in the real world, as such it remains classified as antiparasitic drug, not an antiviral drug.