The pharmacokinetics of [3H]-vincristine in man

Clin Pharmacol Ther. 1977 Oct;22(4):430-5. doi: 10.1002/cpt1977224430.


The pharmacokinetics, metabolism, and excretion of aromatically labeled tritiated vincristine (VCR) was examined in 4 patients. Clearance of radioactivity from the blood was triphasic with half-life t1/2 values of 0.85, 7.4, and 164 min. The initial phases probably represent distribution and binding to formed blood elements which exceeded 50% of the administered dose by 20 min. Excretion of radioactivity was principally fecal, with 33% recovered in the feces by 24 hr and 69% by 72 hr. Considerably less radioactivity (12%) was excreted in the urine over the 72-hr period. Approximately 40% of fecally excreted and 46% of urinary excreted radiolabel represented metabolites, which suggests that at least 34% of the VCR dose was excreted as metabolies. Plasma metabolites represented from less than 1% to 30% or more of radioactivity in plasma. Ultraviolet spectral analysis of all metabolites revealed preservation of the intact VCR dimer, which suggests that metabolism involves alteration of side groups.

MeSH terms

  • Adult
  • Feces / analysis
  • Female
  • Half-Life
  • Humans
  • Kinetics
  • Lymphoma / metabolism
  • Male
  • Middle Aged
  • Tritium
  • Vincristine / blood
  • Vincristine / metabolism*
  • Vincristine / urine


  • Tritium
  • Vincristine