Should chloroquine be laid to rest?

Chloroquine (CQ) has been the front line antimalarial drug due to its efficacy, low cost and scanty side effects, until resistance has evolved. Although its use has been officially discontinued in most malaria-affected countries, it is still widely used. Practical and pharmacological considerations indicate that it could be still used in semi-immune adults and that more efficient treatment protocols could be devised to treat even patients infected with CQ-resistant parasite strains. Since its antimalarial activity is pleiotropic, drug resistance may be due to different mechanisms, each amenable to reversal by drug combination.