Off-Label Prescription of Ivermectin for COVID-19 Purposes

On September 3, 2021, the FDA published the following warnings about individuals using ivermectin to prevent or treat COVID-19:

“Ivermectin tablets are approved by the FDA to treat people with intestinal strongyloidiasis and onchocerciasis, two conditions caused by parasitic worms. In addition, some topical forms of ivermectin are approved to treat external parasites like head lice and for skin conditions such as rosacea. 

Some forms of animal ivermectin are approved to prevent heartworm disease and treat certain internal and external parasites. It’s important to note that these products are different from the ones for people, and safe only when used in animals as prescribed.

The FDA has not authorized or approved ivermectin for the treatment or prevention of COVID-19 in people or animals. Ivermectin has not been shown to be safe or effective for these indications.

There’s a lot of misinformation around, and you may have heard that it’s okay to take large doses of ivermectin. It is not okay. 

Even the levels of ivermectin for approved human uses can interact with other medications, like blood-thinners. You can also overdose on ivermectin, which can cause nausea, vomiting, diarrhea, hypotension (low blood pressure), allergic reactions (itching and hives), dizziness, ataxia (problems with balance), seizures, coma and even death. 

For one thing, animal drugs are often highly concentrated because they are used for large animals like horses and cows, which weigh a lot more than we do—a ton or more. Such high doses can be highly toxic in humans. Moreover, the FDA reviews drugs not just for safety and effectiveness of the active ingredients, but also for the inactive ingredients. Many inactive ingredients found in products for animals aren’t evaluated for use in people. Or they are included in much greater quantity than those used in people. In some cases, we don’t know how those inactive ingredients will affect how ivermectin is absorbed in the human body.”

The FDA’s pronouncement was directed not so much toward prescribing physicians as to members of the public who might have access to veterinary medications, and who might self-administer overdoses of veterinary ivermectin. But what does this mean for prescribing practitioners whose patients are asking for ivermectin prescriptions? 

If the FDA warning were not enough, the practitioner should consider a Merck announcement on February 4, 2021, as the manufacturer of ivermectin, affirming its position against using ivermectin for COVID-19 treatment or prevention:

“Company scientists continue to carefully examine the findings of all available and emerging studies of ivermectin for the treatment of COVID-19 for evidence of efficacy and safety. It is important to note that, to-date, our analysis has identified:

• • No scientific basis for a potential therapeutic effect against COVID-19 from pre-clinical studies; 
  • No meaningful evidence for clinical activity or clinical efficacy in patients with COVID-19 disease, and; 
  • A concerning lack of safety data in the majority of studies.

We do not believe that the data available support the safety and efficacy of ivermectin beyond the doses and populations indicated in the regulatory agency-approved prescribing information.”

In the face of patient demand, especially among rural populations where veterinary versions of ivermectin are readily available, it could be tempting to provide the requested prescription on the rationale that a prescription would at least keep the patient from self-treating and overdosing. But prescribing practitioners do so at their professional peril.

It is not uncommon for physicians to prescribe or administer drugs for off-label uses. The FDA and the AMA both acknowledge that off-label uses can be consistent with the standard of care. However, if off-label drug use is actually stated as “not indicated,” there is a much higher burden upon the prescribing practitioner to produce scientific articles and other resources supporting the safety of the off-label use, and demonstrating that other physicians would order the drug for the off-label use despite the package warning (in this case warnings from both Merck and the FDA).   

Medical professional liability carriers advise that practitioners who are considering prescribing for an off-label use advise that if the literature or package insert states that is “not for” a particular use, the off-label use should generally be avoided. There are multiple suggestions for risk management in the event an off-label use is intended, including contacting the underwriting department of the professional liability insurer to verify coverage of the proposed use of the medication prior to the planned use.

Finally, as emergency departments and ICUs are filled up with unvaccinated patients, overstressed physicians and nurses are turning to professional boards of examiners to seek discipline of licensees who spread misinformation opposing vaccination for COVID-19. To the extent that ivermectin is promoted for treatment or prevention of COVID-19, this could have implications for the licensure of prescribing practitioners willing to support off-label use of ivermectin, particularly if the patient believes that ivermectin is a substitute for vaccination.