The development of an adequate technic for determining plasma quinacrine concentrations1 has facilitated the investigation of several important phases of therapy for soldiers evacuated from the South Pacific with chronic relapsing Plasmodium vivax malaria. The concentrations of quinacrine in plasma attained at selected intervals as the result of oral administration of known amounts of the drug have been determined for specific dosages. Determinations were made on 6,733 specimens from 291 patients during and after treatment for four hundred and twelve attacks of malaria at Harmon General Hospital.
The method of Brodie and Udenfriend1 was employed in the determination of the concentration of quinacrine in plasma. Plasma was used instead of whole blood because these investigators stated that variations in values in whole blood quinacrine concentrations are often reflections of changes in the number of leukocytes, since they contain a concentration several hundred times that of plasma. Shortly