Several classes of antimalarial drugs are available (Table 52–1 and Figure 52–2). Drugs that eliminate developing or dormant liver forms are called tissue schizonticides; those that act on erythro-cytic parasites are blood schizonticides; and those that kill sexual stages and prevent transmission to mosquitoes are gametocides. No single available agent can reliably effect a radical cure, ie, eliminate both hepatic and erythrocytic stages. Few available agents are causal prophylactic drugs, ie, capable of preventing erythro-cytic infection. However, all effective chemoprophylactic agents kill erythrocytic parasites before they increase sufficiently in num-ber to cause clinical disease.