<prompt> All are true regarding chloroquine, EXCEPT :Acts only on exo erythrocytic cycleActs on DNA and RNA of parasiteCauses pigmentation of nail and mucosaInfected RBC has more drug  <response>: Ans. is a acts only on exoerythrocytic cycle.Reference KDT 5th p. 739 4th page 793Chloroquine is a rapidly acting erythrocytic schizonticide. It is active against all species of plasmodium.It has no effect on pre and exoerythrocytic phase of the parasite.Mechanism of action of chloroquine :First chloroquine is concentrated inside infected erythrocytes. Higher cone in infected RBC.Prevents the polymerization of heme into hemozoinHeme damages the plasmodium membrane.About choice B K.D.T. says - The earlier hypothesis that chloroquine acts by interfering with DNA function is now considered untenable 