Ivermectin Safety Trial Confirms Drug Can Be Safely Used in Children as Small as 5 kg
Key Insights
A double-blind clinical trial with 240 participants in Gambia, Kenya, and Brazil confirms ivermectin can be safely administered to children weighing as little as 5 kilograms (11 pounds).
The study found only one serious adverse event—a transient liver enzyme increase that resolved after 32 days—with all other treatment-related events being mild and self-limiting.
This finding could significantly expand mass drug administration campaigns against neglected tropical diseases, as current manufacturer labeling restricts ivermectin use to children over 15 kilograms.
A multicenter clinical trial has demonstrated that ivermectin can be safely administered to very young children weighing as little as 5 kilograms, potentially expanding treatment access for millions of children currently excluded from mass drug administration campaigns against neglected tropical diseases.
The double-blind study, conducted across three countries—Gambia, Kenya, and Brazil—enrolled 240 scabies (search)-infected children weighing between 5 and 15 kilograms. Participants were randomly assigned to receive ivermectin treatments at doses of 200, 400, or 800 micrograms per kilogram, co-administered with placebo cream, or placebo tablets with permethrin cream.
Trial Results Show Strong Safety Profile
The safety analysis revealed only one serious adverse event: a transient liver enzyme increase that returned to baseline levels after 32 days. All other adverse events possibly related to treatment were mild and self-limiting, similar to those observed in people weighing more than 15 kilograms.
"Our double-blind study found that ivermectin can be given to young children who weigh as little 5 kilograms or about 11 pounds—and that's significant because these children are particularly vulnerable to the many diseases currently treatable by ivermectin," said Kevin Kobylinski, PhD, a University of Oxford honorary visiting research fellow with the Mahidol Oxford Tropical Medicine Research Unit (search) in Bangkok and the lead author of the study.
Addressing Current Treatment Gaps
Existing manufacturer labeling restricts ivermectin administration to children under 15 kilograms, despite previous analyses of multiple ivermectin studies showing instances where children weighing as little as 5 kilograms received the drug without serious problems reported.
The restriction has significant implications for mass drug administration campaigns, which are designed to treat entire village populations. Kobylinski noted that including small children in these efforts could substantially increase their impact across several disease areas.
Clinical Impact Across Multiple Diseases
Small children face particular vulnerabilities to ivermectin-susceptible diseases. They are at highest risk for stunting and cognitive complications caused by intestinal worm infections. Additionally, young children are especially vulnerable to scabies (search), a parasitic infestation causing intense itching and skin sores that can lead to bacterial infections and other complications.
For onchocerciasis (search) elimination campaigns, the inclusion of young children could address nodding syndrome (search), a form of debilitating onchocerciasis-associated epilepsy that may be triggered by immune reactions to infections at very young ages.
The study also has implications for malaria (search) transmission suppression. Evidence suggests ivermectin can suppress malaria transmission, but only when mass drug administration campaigns reach approximately 70% of the targeted population—a threshold difficult to achieve when excluding children under 15 kilograms.
Methodological Approach
Investigators collected venous blood samples on days 0, 3, 7, 10, and 14 for biochemistry, pharmacokinetic, and hematology measurements. The trial evaluated not only safety but also efficacy and pharmacokinetics of ivermectin in the small children population.
"Outcomes from the Ivermectin Safety in Small Children trial will hopefully provide greater reassurance that ivermectin can be safely used in children weighing less than 15 kilograms," Kobylinski stated.
Global Health Implications
ASTMH President David Fidock, PhD, the CS Hamish Young Professor of Microbiology and Immunology and Professor of Medical Sciences at Columbia University Irving Medical Center, emphasized the broader significance: "Ivermectin has provided a foundation of some of the most successful interventions in global health, and evidence that it could be safely given to young children could help this work achieve an even greater impact."
The findings were presented at the Annual Meeting of the American Society of Tropical Medicine and Hygiene (search), marking a potential shift in treatment protocols for neglected tropical diseases affecting the world's most vulnerable pediatric populations.