Clinical Scorecard: Pharmacometric Evaluation of Ivermectin Dosing Strategies in Kenya to Guide Mass Drug Administration for Malaria Vector Control

At a Glance

Key Highlights

• In the BOHEMIA trials, monthly mass drug administration with 400 µg/kg ivermectin for 3 consecutive months reduced malaria incidence by 26% versus an albendazole control in children aged 5–15 years.

• Model-based simulations showed ivermectin concentrations remained above the estimated Anopheles gambiae LC50 for 6.3 days after a single 400 µg/kg dose and 8.5 days after a 3-day regimen of 300 µg/kg.

• Dried blood spot ivermectin concentrations were strongly correlated with plasma concentrations (R² = 0.93), and agreement improved after correction for hematocrit and protein binding.

• The 3-day regimen produced a longer modeled duration above the LC50 but was sensitive to missed doses, while a single 400 µg/kg dose could simplify implementation and improve adherence in mass drug administration campaigns.

Guideline-Based Recommendations

Diagnosis

• The study did not evaluate diagnostic strategies or provide diagnostic recommendations for malaria.

Management

• The study did not establish a clinical treatment recommendation. It evaluated ivermectin dosing strategies to inform malaria vector-control trials and deployment planning.

• The authors concluded that a single 400 µg/kg dose could simplify implementation, reduce operational costs, and increase adherence compared with a multidose strategy.

Monitoring & Follow-up

• The study used pharmacokinetic assessment to characterize ivermectin exposure and the modeled duration that plasma concentrations remained above the estimated A gambiae LC50.

• Dried blood spot microsampling may provide a practical alternative to plasma sampling in field trials where venous blood collection is less practical.

Risks

• No severe adverse events were reported among the study volunteers.

• The 3-day regimen was sensitive to missed doses, which shortened the modeled duration above the LC50.

• The study did not evaluate ivermectin resistance in mosquito populations.

Patient & Prescribing Data

The pharmacokinetic model was based on 18 healthy Kenyan adults treated with ivermectin: 12 received a single 400 µg/kg dose and 6 received 300 µg/kg on 3 consecutive days. These data were used to characterize exposure and inform dose selection and deployment strategies for malaria vector control.

Clinical Best Practices

• The findings suggest considering the operational advantages of single-encounter dosing when designing ivermectin mass drug administration strategies.

• The sensitivity of multidose regimens to missed doses should be considered when planning future trials and deployment campaigns.

• Dried blood spot microsampling may be useful for pharmacokinetic field studies because it requires little blood, permits finger-prick collection, simplifies transport without a cold chain, and maintains sample stability under field conditions.

Related Resources & Content

1. Chaccour C, Maia M, Kariuki M, et al. Ivermectin to control malaria — a cluster-randomized trial. New England Journal of Medicine. 2025;393:362–375.

2. Kamau Y, Tuwei M, Wanjiku C, et al. Mosquitocidal efficacy and pharmacokinetics of single-dose ivermectin versus three-day dose regimen for malaria vector control compared with albendazole and no treatment: an open-label randomized controlled trial. International Journal of Infectious Diseases. 2024;148:107236.

3. Smit MR, Ochomo EO, Aljayyoussi G, et al. Safety and mosquitocidal efficacy of high-dose ivermectin when co-administered with dihydroartemisinin-piperaquine in Kenyan adults with uncomplicated malaria (IVERMAL): a randomised, double-blind, placebo-controlled trial. Lancet Infectious Diseases. 2018;18:615–626.

4. Smit MR, Ochomo EO, Waterhouse D, et al. Pharmacokinetics-pharmacodynamics of high-dose ivermectin with dihydroartemisinin-piperaquine on mosquitocidal activity and QT-prolongation (IVERMAL). Clinical Pharmacology & Therapeutics. 2019;105:388–401.

5. Duthaler U, Suenderhauf C, Karlsson MO, et al. Population pharmacokinetics of oral ivermectin in venous plasma and dried blood spots in healthy volunteers. British Journal of Clinical Pharmacology. 2019;85:626–633.

6. Kern C, Müller P, Chaccour C, et al. Pharmacokinetics of ivermectin metabolites and their activity against Anopheles stephensi mosquitoes. Malaria Journal. 2023;22:194.

7. Somé AF, Somé A, Sougué E, et al. Safety and efficacy of repeat ivermectin mass drug administrations for malaria control (RIMDAMAL II): a phase 3, double-blind, placebo-controlled, cluster-randomised, parallel-group trial. Lancet Infectious Diseases. 2025;25:737–750.