Which of the following antimalarial drugs is safe for use in pregnancy?

Proguanil (Chloroguanide) It is a slow-acting erythrocytic schizontocide which also ihibits the preerythrocytic stage of P. falciparum. Gametocytes exposed to proguanil are not killed but fail to develop properly in the mosquito. It is cyclized in the body to a triazine derivative (cycloguanil) which inhibits plasmodial DHFRase in preference to the mammalian enzyme. Resistance to proguanil develops rapidly due to mutational changes in the plasmodial DHFRase enzyme. Current use of proguanil is restricted to prophylaxis of malaria in combination with chloroquine in areas of low level chloroquineresistance among P. falciparum. It can be employed during pregnancy. Essentials of medical pharmacology K D Tripathi Sixth edition Pg no 789: