Artemisinin combination therapy (ACT) has been widely adopted as first-line treatment for uncomplicated falciparum malaria [1–3]. Although these drug combinations appear to be safe and well-tolerated, experience with their use in Africa is still limited [4, 5]. Uganda recently adopted ACT, whereby artemether + lumefantrine (AL, Coartem®) was recommended as first-line regimen for treatment of falciparum malaria. AL, however, has several limitations including twice-daily dosing regimen and recommendation to administer the drug together with fatty food .
Amodiaquine (AQ) is a 4-aminoquinoline drug that has demonstrated sustainable efficacy compared to other anti-malarial drugs [7–9]. In view of low cost and high efficacy, AQ has been considered as a viable anti-malarial agent despite reported low risk of agranulocytosis during long term use [10–13]. Amodiaquine plus artesunate (AQ+AS), is recommended as an alternative first-line regimen to AL for the treatment of uncomplicated malaria in Uganda and many other African countries . Since AQ+AS combination is more affordable than AL, it will most likely find extensive use in the general population.
Generally, most of the malaria endemic areas are rural. These areas usually suffer from shortage of resources, for example electricity, which is required during collection of samples such as plasma. Furthermore, adsorption and drying of whole blood samples on filter paper is known to reduce the risk of exposure to HIV, hepatitis B and C virus, and other infectious agents , thus making sample collection and subsequent handling relatively safe.
Thus, in order perform clinical studies necessary for evaluation of AQ+AS impact in such areas, field-adapted sample collection and robust analytical techniques for monitoring AQ levels in blood and other body fluids are needed. Methods for determination of amodiaquine and its metabolite, desethylamodiaquine (DAQ) from plasma, whole blood and urine have been reported [16–18], but until recently there were none, where amodiaquine was dried on filter paper under field conditions, all previous attempts to store AQ on filter paper were futile [16, 17]. The other two filter paper methods reported for AQ [19, 20] were not suitable for field conditions and were expensive for resource-limited settings.
A new field-adapted filter paper method was recently developed for determination of amodiaquine from whole blood spotted on filter paper . The aims of this study were to explore the practical applicability of the developed analytical procedure for determination of amodiaquine from whole blood dried on filter paper in the field, and to verify whether the measured drug levels correlate to the parasite clearance in children on treatment with AQ+AS combination.