For the past week, Dr. Gregory Yu, an emergency physician in San Antonio, has received the same daily requests from his patients, some vaccinated for Covid-19 and others unvaccinated: They ask him for ivermectin, a drug typically used to treat parasitic worms that has repeatedly failed in clinical trials to help people infected with the coronavirus.
Dr. Yu has refused the ivermectin requests, he said, but he knows some of his colleagues have not. Prescriptions for ivermectin have seen a sharp rise in recent weeks, jumping to more than 88,000 per week in mid-August from a prepandemic baseline average of 3,600 per week, according to researchers from the Centers for Disease Control and Prevention.
Some pharmacists are even reporting shortages of the drug. Travis Walthall, a pharmacist in Kuna, Idaho, a town of about 20,000 people, said that this summer alone he had filled more than 20 ivermectin prescriptions, up from two or three in a typical year. For the past week he has not been able to obtain the drug from his suppliers; they were all out.
Mr. Walthall was astonished, he said, at how many people were willing to take an unapproved drug for Covid. “I’m like, gosh, this is horrible,” he said.
While sometimes given to humans in small doses for head lice, scabies and other parasites, ivermectin is more commonly used in animals. Physicians are raising alarms about a growing number of people getting the drug from livestock supply centers, where it can come in highly concentrated paste or liquid forms.
Calls to poison control centers about ivermectin exposures have risen dramatically, jumping fivefold over their baseline in July, according to C.D.C. researchers, who cited data from the American Association of Poison Control Centers. Mississippi’s health department said earlier this month that 70 percent of recent calls to the state poison control center had come from people who ingested ivermectin from livestock supply stores.
Dr. Shawn Varney, a toxicologist and medical director for the South Texas Poison Center, said that in 2019 his center received 191 calls about exposure to ivermectin; so far this year the center has received 260 calls and is on pace to reach 390 by the end of the year. The vast majority of the recent calls came from people who took a veterinary product in an attempt to treat or prevent Covid-19.
“Everyone wants some cure for Covid because it’s such a devastating illness,” Dr. Varney said. “I plead with people to stop using ivermectin and get the vaccine because it’s the best protection we have at this point. Everything else is risk after risk.”