Pharmacokinetics of methotrexate administered via the hepatic artery

The pharmacokinetics of moderate doses of methotrexate administered via the hepatic artery were studied in ten patients with cancer metastatic to the liver. Intra-arterial methotrexate showed two-compartment characteristics with a clearance of 79 ml/min/m2 and an apparent volume of distribution of 21.2 l/m2 body surface area. The average half-life of the early phase was 1.9 h and the terminal half-life was 14.4 h. The data were not different from those observed in similar patients after IV administration of equivalent doses of methotrexate.