Methods and techniques for assessing exposure to antimalarial drugs in clinical field studies

Achieving adequate concentrations of antimalarial drugs in the blood is pivotal to curing malaria. Accurate measurement of drug concentrations is essential to ensure optimal dosing of the currently available and newly introduced antimalarial drugs and for differentiating inadequate exposure to a drug from true resistance to the drug. For each drug, answers are needed to two questions: ‘What exposure (concentration over time) is necessary to ensure the required therapeutic effect?’ and ‘Should the recommended dosage be modified for important target populations, such as infants, pregnant women and people with co-morbid conditions (especially HIV/AIDS and malnutrition), to ensure the required therapeutic effect?’ Lower concentrations of several antimalarial drugs have been found in pregnant women and young children than in non-pregnant adults.

This report is the result of an informal consultation organized by the WHO with technical support from the WorldWide Antimalarial Resistance Network in Bangkok, Thailand, from February 22 to 24, 2010.