Changing pattern of antimalarial drug resistance.

With the current increase of international travel and increasing drug resistance, United Kingdom residents stand a high risk of contracting malaria when they visit endemic countries. The development of anti-malarial agents from old traditional plant remedies to modern synthetic drugs is briefly reviewed. Resistance to the latter has spread rapidly since the 1950s, culminating in the widespread distribution of multiple drug-resistant strains of Plasmodium falciparum in most endemic areas. There is a danger that such parasites may rapidly develop resistance even to new compounds such as mefloquine, halofantrine or artemisinin unless the use of such compounds is carefully controlled. The few developments, including new drugs and ways of reversing existing resistance, are also briefly reviewed in this paper. Emphasis is laid on the need to revert to classical methods of protection against malaria vectors since it is unlikely that a protective vaccine will become available in the near future.