Methotrexate with thymidine, inosine, and allopurinol rescue: a phase I clinical study

Cancer Treat Rep. 1981;65 Suppl 1:37-43.


A phase I clinical study of a combination of thymidine (TdR), inosine (IR), and allopurinol used as rescue from 24-hour infusions of methotrexate (MTX) was undertaken following animal studies that had shown a better preservation of antitumor activity with this system than with folinic acid. TdR and IR were given in the dose ratio 5:1 by weight throughout. Rescue from MTX, 400 mg/m2, could be achieved with a TdR dose in the combination of 1 g/m2/24 hours. This same rescue was also effective when the MTX dose was increased to 800 mg/m2, but only partly effective at an MTX dose of 1.5 g/m2. It was not necessary to raise the levels of circulating nucleosides significantly above normal to achieve rescue. MTX-related skin lesions occurred more frequently than might be expected with the MTX dose used.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Aged
  • Allopurinol / administration & dosage
  • Drug Administration Schedule
  • Drug Evaluation
  • Drug Therapy, Combination
  • Female
  • Humans
  • Hypoxanthines / blood
  • Infusions, Parenteral
  • Inosine / administration & dosage
  • Male
  • Methotrexate / administration & dosage*
  • Methotrexate / adverse effects
  • Middle Aged
  • Thymidine / administration & dosage
  • Uric Acid / blood


  • Hypoxanthines
  • Uric Acid
  • Inosine
  • Allopurinol
  • Thymidine
  • Methotrexate