What have poison control centers and hospitals reported about ivermectin-related adverse events since OTC laws took effect?
Executive summary
Poison control centers and hospitals documented a clear surge in ivermectin-related exposures and toxicity reports during the COVID-19 era, with public health agencies and academic centers citing increases in calls, emergency visits and hospitalizations tied to misuse and overdoses—often involving veterinary formulations or supratherapeutic dosing [1][2][3]. Available pharmacovigilance analyses and case series emphasize neurologic and gastrointestinal toxicity as the dominant serious manifestations, but the sources do not provide systematic evidence linking those adverse-event trends specifically to newly enacted state OTC ivermectin laws [4][5][6].
1. Poison centers recorded abrupt spikes in calls tied to misuse and overdoses
Multiple public health reports documented that calls to poison control about ivermectin rose sharply beginning in 2020 and spiked in 2021—CDC’s health advisory and the Oregon Poison Center both reported far higher call volumes than pre-pandemic baselines, with one center moving from roughly 0.25 calls per month in 2020 to 21 calls in a single month in August 2021 [1][2]; WHO pharmacovigilance data similarly show dramatic increases in ivermectin-related reports since mid‑2020 [5].
2. Hospitals reported serious illnesses and some intensive-care admissions
Clinical summaries and case series show that a subset of callers required emergency care and inpatient treatment: the Oregon series found six of 21 patients were hospitalized, four of them in intensive care, with presentations including gastrointestinal distress, confusion, ataxia, hypotension and seizures; none of those cases in that report died, but hospital-level care was commonly required [2][7]. Public health alerts from CDC and FDA also explicitly note increases in emergency-department visits and hospitalizations tied to overdose or misuse [1][3].
3. Neurologic toxicity and GI effects predominate in reported serious events
Across pharmacovigilance projects and literature reviews, neurologic adverse events—dizziness, confusion, ataxia, seizures and more severe encephalopathies—feature prominently among serious reports, often alongside gastrointestinal symptoms such as nausea and vomiting; FACT and WHO database analyses emphasize neurologic toxicity as the most frequent severe manifestation in COVID‑19–related misuse cases [4][5][8].
4. Veterinary products and excessive dosing are recurring drivers of harm
Investigations and regulatory communications repeatedly identify use of veterinary ivermectin formulations and large, inappropriate doses as critical risk factors for toxicity: many poison-center reports involved veterinary paste or solutions not intended for humans, and FDA and CDC warnings recount patients requiring medical attention after self-medicating with animal products [2][3][9].
5. Pharmacovigilance signals exist but serious events remain uncommon relative to global use for approved indications
Systematic studies of global adverse-event databases document cases of serious neurologic and other adverse reactions, and signal-detection efforts have flagged disproportional reporting in some datasets, but authors emphasize that severe events are rare relative to the long history of ivermectin’s safe use for approved parasitic indications; nonetheless, pharmacovigilance analyses call for caution, especially outside approved uses and in populations with potential co‑infections or interacting drugs [10][11][12].
6. Policy changes (OTC laws) are a potential new variable — but causal data are lacking
Several states have passed laws expanding OTC access to ivermectin, a move flagged by pharmacy and public‑health commentators as raising risks for self‑medication and adverse effects; however, the reporting reviewed documents adverse-event trends predominantly from 2020–2021 and contains no systematic, contemporaneous analysis isolating the impact of these newer OTC statutes on poisoning or hospitalization rates, so a causal link cannot be established from these sources [6][1][2].
7. Bottom line: documented harms tied to misuse; effect of OTC laws unresolved
Poison centers and hospitals have documented increased exposures, emergency visits and some serious hospitalizations tied to ivermectin misuse—frequently involving veterinary products and overdosing—with neurologic toxicity a leading concern, but current published surveillance and studies in these sources do not yet show a quantified change in adverse-event rates attributable specifically to the recent state OTC laws, leaving that policy question open for targeted post‑law monitoring and research [2][3][6].