CHLOROQUINE It is a rapidly acting erythrocytic schizontocide against all species of plasmodia; controls most clinical attacks in 1-2 days with disappearance of parasites from peripheral blood in 1-3 days. Therapeutic plasma concentrations are in the range of 15-30 ng/ml. However, it has no effect on pre- and exo-erythrocytic phases of the parasite-does not prevent relapses in vivax and ovale malaria. Resistance in P. falciparum is associated with a decreased ability of the parasite to accumulate chloroquine. Veraparnil, a Ca2+ channel blocker, has been found to restore both the chloroquine concentrating ability as well as sensitivity to this drug. For pediatric patients, the treatment options are the same as for adults except the drug dose is adjusted by patient weight. The pediatric dose should never exceed the recommended adult dose. Pediatric dosing may be difficult due to unavailability of non-capsule forms of quinine. If unable to provide pediatric doses of quinine, consider one of the other three options. If using a quinine-based regimen for children less than eight years old, doxycycline and tetracycline are generally not indicated; therefore, quinine can be given alone for a full 7 days regardless of where the infection was acquired or given in combination with clindamycin as recommended above. In rare instances, doxycycline or tetracycline can be used in combination with quinine in children less than 8 years old if other treatment options are not available or are not tolerated, and the benefit of adding doxycycline or tetracycline is judged to outweigh the risk. If infections initially attributed to "species not identified" are subsequently diagnosed as being due to P. vivax or P. ovale, additional treatment with primaquine should be administered. ESSENTIALS OF MEDICAL PHARMACOLOGY, www.cdc.gov/malaria/diagnosis_treatment K.D.TRIPATHI SIXTH EDITION PAGE NO:785