A study of the distribution of methotrexate in human tissues and tumors.

Abstract

Summary Methotrexate (Mtx) is readily detectable in varying concentrations in many tissues and tumors assayed, regardless of the mode of administration. In general, tissue that is within an area of arterial infusion has a higher Mtx concentration than tissue obtained from outside the area of infusion. Higher and sustained Mtx tissue levels were achieved by prolonged and continuous administration of the drug as opposed to single dose administration. The higher dose resulted in higher but not directly proportional levels of Mtx in tissue. When Mtx is administered as a single injection either i.v. or by regional intraarterial administration at the same dosage, the intraarterial route results in higher tissue concentration of the drug. These results do not answer all questions pertaining to the distribution of Mtx in human tissues and tumors and are merely presented as preliminary data. Further studies in this area are currently in progress.