New Evidence Shows Ivermectin's Efficacy in Malaria Control

Malaria remains a major global health concern. In 2023, there were about 263 million cases and nearly 600,000 deaths, most of which occurred in Sub-Saharan Africa. Insecticide-resistant Anopheles mosquitoes and outdoor/early evening biting behavior are reducing the efficacy of traditional control techniques, such as indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs).¹ These trends have led to an increase in the use of drug treatments that target malaria vectors, especially mass drug administration (MDA) with ivermectin (Stromectol; Merck).¹

Image Credit: Jeffrey Daly | stock.adobe.com

The results of the largest community-based ivermectin efficacy study to date, the Broad One Health Endectocide-based Malaria Intervention in Africa (BOHEMIA), were published in the New England Journal of Medicine in July 2025.² For 3 months, more than 28,900 individuals in 84 clusters in Kwale County, Kenya, received monthly doses of either albendazole (Albenza; Teva Pharmaceuticals USA) or ivermectin for 3 months in a row. In the ivermectin group, the number of malaria cases per child-year among children aged 5 to 15 years went down from 2.66 to 2.20, representing a 26% drop.² Serious adverse effects (AEs) were rare and evenly distributed between the 2 groups, which suggests that the safety profile was favorable.²

A Pharmacist's Role

In both endemic and lower-incidence countries, pharmacists can be essential in carrying out ivermectin MDA campaigns and preparing for emergencies. Accurate weight-based dosing, maintaining supply chain integrity, creating pharmacovigilance protocols, and educating the public are among the duties of pharmacists in endemic deployment. Because ivermectin is transported by P-glycoprotein and metabolized by CYP3A4, drug interactions—including those with immunosuppressants, benzodiazepines, and statins—need to be closely monitored.³ Although ivermectin was well-tolerated in BOHEMIA participants, pharmacists should warn patients about mild AEs such as fatigue, gastrointestinal distress, or dizziness.

Pharmacists in the United States could support new preparedness strategies by participating in surveillance planning, ensuring access to antimalarial treatments (including intravenous artesunate for severe cases), counseling travelers through travel health programs, and contributing to public health messaging. Information regarding ivermectin's potential role as a vector-control intervention for emergency or global health deployments could be included by travel-medicine pharmacists who are already familiar with prescribing drugs like mefloquine, doxycycline, and atovaquone-proguanil.

A New Approach to Vector Control

BOHEMIA reveals a novel mode of action: ivermectin functions as a systemic insecticide, killing mosquitoes that feed on treated humans. This vector-control approach boosts LLIN2 efficacy while avoiding insecticide resistance. Experts from institutions such as Oxford University, ISGlobal, and the Kenya Medical Research Institute (KEMRI) say these findings meet WHO efficacy requirements for new vector-control tools.⁴

Emerging US Relevance Amid Shifting Malaria Risks

Recent events demonstrate how applicable these findings are domestically, even though malaria is not endemic in the United States. In a Health Alert (HAN 00494) issued on June 26, 2023, the CDC reported 8 locally acquired cases of Plasmodium vivax malaria in Florida (7 cases) and Texas (1 case). Since 2003, this was the first time the disease had been spread in the US. In August 2023, a follow-up alert (HAN 00496) that identified another Plasmodium falciparum case in Maryland underscored the importance of continued vigilance.⁵ Although the overall risk is still very low, these cases demonstrate that climate change and international travel may increase the threats of vector-borne diseases, even in historically nonendemic regions.^5,6

Monthly ivermectin MDA significantly lowers malaria incidence in endemic settings with high safety, according to the BOHEMIA trial. Pharmacists are essential to the success of programs because of their expertise in dosing, safety monitoring, education, and logistics. Even in areas such as the US—where malaria is rare—the pharmacist's role in preparation, outbreak response, and public education is growing in importance due to recent local transmission events and climate-driven changes.

REFERENCES

1. World Health Organization. World Malaria Report 2023. www.who.int. Published 2023. https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2023

2. Chaccour C, Maia M, Kariuki M, et al. Ivermectin to Control Malaria — A Cluster-Randomized Trial. N Engl J Med. 2025;393(4):362-375. doi:10.1056/nejmoa2411262

3. Center for Infectious Disease Research and Policy. CIDRAP. Published July 25, 2025. Accessed July 31, 2025. https://www.cidrap.umn.edu/malaria/new-findings-support-ivermectin-malaria-control

4. New research finds that ivermectin could help control malaria transmission — Nuffield Department of Medicine. Ox.ac.uk. Published July 24, 2025. Accessed July 31, 2025. https://www.ndm.ox.ac.uk/news/new-research-supports-ivermectin-as-an-effective-strategy-to-control-malaria-transmission

5. Health Alert Network (HAN) - 00494 | Locally Acquired Malaria Cases Identified in the United States. Cdc.gov. Published December 5, 2024. https://www.cdc.gov/han/2023/han00494.html

6. Health Alert Network (HAN) - 00496 | Important Updates on Locally Acquired Malaria Cases Identified in Florida, Texas, and Maryland. Cdc.gov. Published January 31, 2025. https://www.cdc.gov/han/2023/han00496.html