Does Ivermectin Lower Seizure Threshold?
No, ivermectin does not lower seizure threshold based on available evidence. In fact, there is some evidence suggesting it may have anticonvulsant properties in certain populations.
Evidence Regarding Ivermectin and Seizure Risk
Unlike some other antiparasitic medications such as lindane, which has been associated with seizures, ivermectin has not been documented to lower seizure threshold in clinical guidelines 1.
Guidelines specifically mention seizure concerns with other medications but do not include such warnings for ivermectin:
The CDC/MMWR guidelines that discuss medications affecting seizure threshold do not list ivermectin among medications that lower seizure threshold 1.
Potential Anticonvulsant Effects of Ivermectin
Some research suggests ivermectin may actually have anticonvulsant properties:
A 2017 observational study reported that ivermectin used as adjunctive treatment in refractory epilepsy patients resulted in a 97% reduction in seizures, with 57% of patients becoming seizure-free 2.
Studies in onchocerciasis-infected persons with epilepsy have shown that ivermectin treatment was associated with reduced seizure frequency 3, 4.
A 2020 study found that increasing the number of ivermectin treatments suppressed both microfilarial density and seizure frequency in onchocerciasis-infected persons with epilepsy 3.
Mechanism of Action and CNS Effects
Ivermectin has limited penetration across the blood-brain barrier in mammals with intact barrier function, which may explain its favorable safety profile regarding CNS effects 5.
The anticonvulsant effects observed in onchocerciasis-infected persons may be primarily due to reduction in parasite load rather than direct effects on neural tissue 4, 5.
Clinical Considerations
Ivermectin is considered to have "low risk" in pregnancy and is compatible with breastfeeding 1.
When prescribing ivermectin, standard dosing is 200 μg/kg orally, which can be repeated in 2 weeks for certain parasitic infections 1.
Unlike medications such as bupropion (which is known to lower seizure threshold), ivermectin is not contraindicated in patients with seizure disorders 1.
Conclusion
Current guidelines and research do not support concerns about ivermectin lowering seizure threshold 1.
For patients with seizure disorders requiring antiparasitic treatment, ivermectin appears to be a safer choice compared to alternatives like lindane 1.
Some evidence even suggests potential benefit in certain epilepsy populations, though more controlled studies are needed to confirm these findings 2, 3, 4, 6.