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■Bio-mathematics, Statistics and Nano-Technologies: Mosquito Control Strategies

A different ACT with known efficacy in the area can be used as the second line of

treatment when failure happens within 28 days. However, a treatment after 28 days of the

first treatment ought to be regarded as new diseases and should be treated using the first

line ACT, except for mefloquine that cannot be reused within 60 days of initial treatment,

as it is known to elevate the risk of neuropsychiatric reactions.

The antimalarial action of artemether is dependent on its peroxide bridge. When it in-

teracts with hemoglobin-iron in the food vacuole of the parasite, its endoperoxide bridge

rupture with resultant formation of free radicals. These free radicals will trigger delay of

protein growth throughout development of trophozoites [16]. Artemether also works by

disrupting the mitochondria in the parasite, hindering formation of new blood vessels, and

by modulating the immune role of the host [17, 18].

Lumefantrine acts by blocking the detoxification of hemoglobin, inside the parasite.

When that happens, toxic hemoglobin and free radicals will cause the parasite to die [17].

Patients who are unable to swallow or take oral ACTs are recommended to be given par-

enteral or rectal medication for 24 −48 h until they can swallow or take oral medicine.

10.3

RESISTANCE TO ANTIMALARIAL TREATMENT, A GLOBAL THREAT

Antimalarial drug resistance is defined as the ability of a parasite strain to survive

or multiply despite the proper administration and absorption of an antimalarial drug at the

recommended dose. Drug resistance to an antimalarial compound reflects a right-hand shift

in the concentration–effect (dose–response) relation Figure (10.1).

Resistance is a right-hand shift in the concentration–effect relation for a particular

malaria parasite population. It may be a parallel shift (red) from the “normal” profile

Figure 10.1: The concentration–effect relationship. Emax is the maximal effect of the drug,

where EC50 is the concentration required to induce 50% efficacy.