With a
fourth wave of infections, more Americans are turning to ivermectin, a cheap
drug used to kill worms and other parasites in humans and animals.
Federal
health officials have seen a surge in prescriptions this summer, accompanied by
worrying increases in reported overdoses. The drug was even given to inmates at
a jail in northwest Arkansas for COVID-19, despite federal warnings against
that use. On Wednesday, podcaster Joe Rogan, who has been dismissive of the
COVID-19 vaccine, announced he had tested positive for the virus and was taking
the medication.
Ivermectin
has been promoted by Republican lawmakers, conservative talk show hosts and
some doctors, amplified via social media to millions of Americans who remain
resistant to getting vaccinated. It has also been widely used in other
countries, including India and Brazil.
This week,
the top U.S. professional groups for doctors and pharmacists appealed for an
“immediate end” to the drug’s use outside of research.
“We are
urging physicians, pharmacists, and other prescribers — trusted healthcare
professionals in their communities — to warn patients against the use of
ivermectin outside of FDA-approved indications and guidance,” said the American
Medical Association and two pharmacist groups.
Large
studies are now underway in the U.S. and overseas to determine if the drug has
any effect on preventing or blunting COVID-19.
The latest
plea follows similar warnings from federal and state regulators who are
tracking side effects and hospital admissions tied to the drug.
Louisiana
and Washington issued alerts after an uptick in calls to poison control
centers. Some animal feed supply stores have run out of the drug because of
people buying the veterinary form to try and treat COVID-19.
“There’s
just not any good evidence right now suggesting this is a good treatment for
treating or preventing COVID-19,” said Randy McDonough, a pharmacist in Iowa
City, Iowa
Ivermectin
is approved by the Food and Drug Administration to treat infections of roundworms
and other tiny parasites in humans and animals like cows, horses and dogs.
Tablets are used for internal parasites while ointments are used to treat head
lice and other skin infections. The generic drug works by paralyzing the worms
and killing their offspring.
The FDA has
tried to debunk online claims that animal-strength versions of the drug can
help fight COVID-19.
“Taking
large doses of this drug is dangerous and can cause serious harm,” the FDA
warned in a public advisory. The drug can cause nausea, vomiting, diarrhea,
seizures, delirium and even death, said the agency.
Dr. David
Boulware of the University of Minnesota says the drug’s side effects are mild
at two or even three times the usual human dose. But formulations for farm
animals might contain 1,000 times what’s safe for humans.
“It’s
pretty easy to get into toxic levels,” said Boulware, an infectious disease
specialist. “All these concentrated doses that are meant for a 2,000 pound
horse can certainly get people sick or hospitalized for toxicity.”
Boulware
says he prescribes the drug to patients a few times a year in the U.S. and more
routinely when working in countries where intestinal parasites are common. But
he and other experts have been alarmed by the explosive growth in U.S.
ivermectin prescribing.
By
mid-August U.S. pharmacies were filling 88,000 weekly prescriptions for the
medication, a 24-fold increase from pre-COVID levels, according to the Centers
for Disease Control and Prevention. Meanwhile, U.S. poison control centers have
seen a five-fold increase in emergency calls related to the drug, with some
incidents requiring hospitalization.
The CDC
citedone case of a man who drank an injectable form of ivermectin intended for
cattle. He suffered hallucinations, confusion, tremors and other side effects
before being hospitalized for nine days.
The World Health
Organization, the National Institutes of Health and other medical experts have
also recommended against using it outside of carefully controlled patient
studies. An NIH panel found “insufficient evidence” for or against the drug for
COVID-19, calling for more large, well-designed trials.
The experts
noted that early laboratory research showed ivermectin slowed the replication
of coronavirus when grown in monkey cells. But such studies are not useful for
gauging real-world effectiveness in humans. And they noted other research
suggesting the drug would need to be given at levels 100 times the standard
dose to have antiviral effects in humans.
The NIH is
studying the drug in a large trial comparing a half-dozen established drugs to
see if they have some effect against COVID-19.
Experts say
those interested in ivermectin should ask about enrolling in such studies.
“By
participating in a clinical trial you’re not going to harm yourself and you’re
going to help society generate the knowledge we need to know if this works or
doesn’t work,” said Boulware.