Drug therapy: Effectiveness of antimalarial drugs

A global public health threat due to the resurgence of malaria stems from a general collapse of vector-control operations and from resistance to chloroquine or sulfadoxine-pyrimethamine. Recent surveys show rates of treatment failure higher than 50 percent for chloroquine in most affected regions, as well as poor efficacy of sulfadoxine-pyrimethamine in sub-Saharan Africa and Southeast Asia. Quinine and mefloquine remain effective therapies everywhere except in some regions bordering Thailand. Resistance to primaquine-the only drug for preventing relapse-probably occurs but has not yet been confirmed. New drugs should be effective among the poor, self-treating rural populations in regions of endemic disease and should be provided through programs that address issues of availability and cost, convenience and adherence, safety and tolerability, and quality assurance. The combination therapies with artemisinin derivatives represent the present best efforts toward providing such therapeutic agents. These drugs deliver an inhibitory effect that substantially reduces the probability of selection for resistant parasites, as compared with traditional monotherapies. However, widespread distribution without complementary capabilities in the delivery of health care places the clinical usefulness of these critical drugs in doubt. Copyright © 2005 Massachusetts Medical Society.