Clinical pharmacology of oral intermediate-dose methotrexate with or without probenecid

Cancer Chemother Pharmacol. 1985;15(3):220-2. doi: 10.1007/BF00263889.


Serum methotrexate (MTX) levels were measured in 20 patients who received an oral, intermediate-dose MTX regimen preceded by an IV loading dose, with or without probenecid. Plateau serum MTX levels were relatively modest (less than or equal to 2 X 10(-6)M) during the 24 h of treatment. Pretreatment with probenecid (PBC) led to a doubling of the serum MTX level and a significant increase in the area under the concentration-time curve. Nevertheless, oral therapy is not a suitable means of producing sustained, high (10(-5) molar) MTX levels, even with the addition of PBC.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Administration, Oral
  • Clinical Trials as Topic
  • Drug Administration Schedule
  • Humans
  • Methotrexate / administration & dosage
  • Methotrexate / blood*
  • Methotrexate / therapeutic use
  • Neoplasms / drug therapy
  • Probenecid / administration & dosage
  • Probenecid / therapeutic use*


  • Probenecid
  • Methotrexate