What are symptoms of ivermectin overdose in humans?

1. Alarming neurologic collapse: what clinicians and poison centers reported

Multiple clinical and public‑health reports emphasize neurologic toxicity as the most serious manifestation of ivermectin overdose, with described symptoms including altered mental status, confusion, decreased awareness, severe sleepiness, loss of consciousness, and seizures. Poison centers and state health departments collected case series where people required hospitalization and intensive care for central nervous system depression and seizures after taking ivermectin at high doses or animal formulations ^{[4] [6] [5]}. These sources note that neurologic signs often accompany other systemic features and can progress rapidly; therefore, emergency evaluation is recommended when cognitive decline, unresponsiveness, or convulsions occur following exposure ^{[1] [2]}.

2. Digestive distress and skin signs: common early signals to watch

Early and more common signs of toxicity are gastrointestinal and dermatologic: nausea, vomiting, abdominal pain, and diarrhea appear frequently in reported cases and can be accompanied by skin reactions such as itching, hives, rash, or more severe blistering and peeling. Clinical summaries and patient reports catalog these symptoms as typical initial presentations that may prompt emergency visits, and they frequently precede or accompany neurologic or cardiovascular complications. Because these symptoms are nonspecific, clinicians use them alongside exposure history to suspect ivermectin overdose, particularly when accompanied by visual disturbances or somnolence ^{[7] [2]}.

3. Cardio‑respiratory instability: hypotension, tachycardia and breathing problems

Cardiovascular and respiratory signs form another dangerous cluster: hypotension (low blood pressure), rapid heart rate, and difficulty breathing have been reported in severe toxicity. State health advisories and clinical overviews highlight cases where hypotension and tachycardia required monitoring or hemodynamic support, and where respiratory depression necessitated oxygen or ventilation. Those sources warn that ivermectin can amplify central nervous system‑depressant effects of other medications (for example benzodiazepines or barbiturates), increasing the risk of respiratory failure when co‑ingestants are present ^{[1] [7] [8]}.

4. Organ and sensory damage: eyes, liver signals, and other systemic signs

Beyond immediate neurologic and cardio‑digestive effects, reports document eye irritation, vision problems, jaundice, dark urine, and signs of hepatic injury in some overdoses, with occasional mention of swollen lymph nodes, joint or muscle pain, and urinary or bowel‑control loss. Public‑health communications and drug safety pages catalog these less frequent but clinically important manifestations as part of the toxicity spectrum; severe hepatic involvement and metabolic derangements have appeared in cases with prolonged or very high dosing and required hospital workup for liver function and systemic complications ^{[9] [2] [5]}.

5. Consensus, controversy and public‑messaging: why risks rose in 2021–2022

A clear consensus across state health advisories, poison‑center reports, and clinical summaries is that overdose risk rose when people self‑medicated with veterinary ivermectin or used doses far above approved therapeutic regimens, producing poisonings that drove emergency visits and hospitalizations, particularly during the 2021–2022 period when misinformation circulated widely ^{[8] [3]}. Reporting varies in granularity—some sources focus on case counts and hospital burden, others on detailed symptom lists—yet all converge on the same clinical red flags and the recommendation to seek urgent medical care for neurologic, respiratory, or cardiovascular compromise ^{[4] [6] [5]}. Potential agendas include public‑health bodies emphasizing harm reduction and clinical vigilance, while media pieces often highlight sensational cases to warn the public; readers should weigh both types of coverage together.