Despite a lack of evidence that ivermectin was an effective or safe COVID-19 treatment, dispensing of the antiparasitic drug surged in US retail pharmacies—but not in Veterans Administration (VA) facilities—after March 2020, finds a University of Michigan-led study.
The research, published yesterday in JAMA Network Open, involved extraction of VA-filled ivermectin prescriptions from the VA's Corporate Data Warehouse from June 2019 to February 2022. Data on US retail pharmacy ivermectin fills from the same period were pulled from the IQVIA National Prescription Audit, which captures 92% of prescriptions at these pharmacies.
Dispensing of the unproven COVID-19 treatment "potentially harmed patients while resulting in wasteful insurer spending," the authors wrote. They noted that the VA has a national formulary that may reduce prescribing of ineffective drugs; in September 2021, the VA developed national criteria that restricted ivermectin prescribing to parasitic infections but allowed decisions to be made on a case-by-case basis per local facility policy.
Previous research also showed a surge in ivermectin fills at US retail pharmacies in spring 2020.
Formulary debut tied to immediate drop
Before March 2020, ivermectin dispensing was minimal at both pharmacy types, but after the pandemic began, retail pharmacies filled 2,362,572 ivermectin prescriptions, and VA pharmacies dispensed 7,434. The VA's formulary limitations were tied to an immediate reduction in ivermectin dispensing of 2.83 prescriptions per 100,000 people (95% CI, −3.80 to −1.86) but no change in the overall trend.
Through September 2021, retail pharmacies dispensed 2.17 more prescriptions per 100,000 people per month (95% confidence interval [CI], 1.29 to 3.05) than before the pandemic, while VA facilities filled only 0.14 more (95% CI, 0.08 to 0.21).
The researchers said that future studies should delve into why the steep increase in ivermectin fills by retail pharmacies wasn't observed in VA facilities.
Through September 2021, retail pharmacies dispensed 2.17 more ivermectin prescriptions per 100,000 people per month than before the pandemic, while VA facilities filled only 0.14 more.
"Local VA facility restrictions in ivermectin use may have existed before September 2021," they wrote. "Another possibility is that inappropriate demand for ivermectin increased less among veterans compared with nonveterans. Distinguishing between these possibilities could inform the design of interventions to decrease future provision of low-value care for COVID-19 and other conditions."
The association between the VA formulary restriction and the drop in ivermectin prescribing, they added, highlights "the ability of coverage restrictions to reduce the use of ineffective care. Such restrictions should be implemented carefully to avoid unintended consequences for patient access."
From 'miracle' to failure
Ivermectin was widely touted as a "miracle" treatment for COVID-19 amid a race to test drugs already approved for other indications early in the pandemic, before vaccines and effective treatments were available. From July to August 2021, US poison control centers saw a 245% jump in ivermectin overdose calls.
Since then, a slew of studies have debunked ivermectin as a COVID-19 treatment, finding it futile for mild to moderate illness, prevention of hospitalization, or time to recovery from nonsevere disease. The US Food and Drug Administration (FDA) didn't authorize the drug for COVID-19 and issued warnings about its potential harm.