What is ivermectin?
Ivermectin is an FDA-approved drug that is used to treat parasitic infections. It can be administered orally or applied topically to treat scabies, lice infestation, and bedbug infestation. It is taken orally to treat stomach parasites that are common in the tropics. Ivermectin is a member of a class of drugs known as the avermectin family. These drugs work by paralyzing parasites by causing electrolyte instability and impairing the nerve function of said parasites. Eventually the parasites starve to death as they as unable to feed.
Ivermectin has also been used to treat rosacea. Rosacea is a chronic skin condition that is characterized by red lesions which appear as a result of dilatation of superficial blood vessels. The cause is unknown but it has been linked to a species of mites. Topical ivermectin kills off these mites and reduces the symptoms of rosacea.
Ivermectin, especially when taken orally, has side effects. These include nausea, vomiting, diarrhea and abdominal pain. Ivermectin is a neurotoxic agent. In the same way it alters the nerve function of parasites, it can also affect the nervous system in humans, particularly when taken in large doses. This will manifest itself in the form of symptoms such as headache, insomnia, vertigo and muscle weakness.
Finally, some individuals may react to ivermectin whereby their body rejects the drug. This is similar to an allergy but the scientific name for this phenomenon is a hypersensitivity reaction. Despite the possible side effects, ivermectin is on WHO’s list of essential medicines. Thus, it is consider safe and effective when used appropriately under the supervision of a physician.
Ivermectin and Covid-19
Ivermectin is under investigation for its possible role in the treatment of Covid-19. The reason why this drug was seriously considered and selected among all other drugs as a possible candidate is because it has a history of being effective against serious viral infections. In fact, it was studied as a possible cure for Influenza, the Ebola virus and most recently, Zika virus. It was shown to be effective against all these viruses in the experimental setting.
An in vitro study published in April 2020 showed that when a single dose of ivermectin is introduced to a cell infected with SARS-CoV-2 (the virus that causes Covid-19), the number of viruses go down 5000 times over in just two days. Because the study was in vitro, which means it was done in a laboratory setting and only involved single cells, the researchers concluded that more studies were needed.
An international observational study conducted this year also reported good results. The study observed two groups of patients confirmed to have Covid-19. One group was given ivermectin and the other group was given other investigational therapies. The group given ivermectin reported a lower death rate. Even so, the researchers concluded that more studies were needed.
The FDA released an official statement on ivermectin and Covid-19 stating that there was no conclusion yet. The regulatory body stated that trials were at a very early stage and discouraged the public from self medicating. Finally, the FDA stated that studies needed to show that ivermectin is not only effective against Covid-19 but also safe. The studies released so far have proved efficacy in single cells only. In addition, the doses given to cure the single cells, when approximated to the dose required in an adult human, are within the toxic range. But all this is inconclusive. Clinical trials involving infected patients are required to prove both efficacy and safety before ivermectin is officially endorsed.
Ivermectin and Pregnancy
No human studies have been conducted on the effects of ivermectin on pregnancy. However, animal studies done in pregnant mice showed poor outcomes. Thus, ivermectin is considered relatively unsafe for pregnant women. The FDA recommends that its use should only be reserved for special circumstances where the benefits outweigh the risks. Ivermectin is excreted in milk and should not be used by mothers who are breastfeeding. The safety of ivermectin in children who are less than 30 pounds is also questionable.
Ivermectin is likely to prove to be a broad-spectrum antiviral drug in the near future. It is safe, FDA-approved, cost effective and widely available. Thus, it can easily be re-purposed for this indication. As for its use against Covid-19 specifically, no conclusion has been reached so far. Scientists reckon that the dose required for meaningful activity against Covid-19 is unlikely to be achieved without the negative toxic effects. Thus, even if it proves effective, it is unlikely to be first line drug and may be reserved for special circumstances where the patient fails to respond to safer regimens. Finally, ivermectin is currently not considered safe for use in pregnancy.