Metabolic studies of delta-9-tetrahydrocannabinol in cancer patients

Cancer Treat Rep. 1984 Dec;68(12):1427-31.


The metabolism of oral delta-9-tetrahydrocannabinol (THC) was studied in nine patients with gastrointestinal neoplasms receiving chemotherapy regimens containing 5-FU and semustine. Plasma levels of THC and its metabolites 11-OH-delta-9-THC (11-OH-THC) and 11-nor-9-carboxy-delta-9-THC (C-THC) were measured. Plasma levels of THC and its metabolites were quite variable among the patients studied. Plasma levels of THC and 11-OH-THC tended to peak at the same time; the C-THC levels peaked later and lasted much longer than the others. Mean half-lives of THC, 11-OH-THC, and C-THC were estimated to be 1.5, 2.1, and 4.4 hours, respectively. Multiple doses of THC did not produce a significant additive effect on the plasma concentrations of the biologically active metabolites THC and 11-OH-THC. No correlation between antiemetic effect or cannabinoid toxicity and plasma levels of the three metabolites could be made in this small number of patients.

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Dronabinol / analogs & derivatives
  • Dronabinol / blood
  • Dronabinol / metabolism*
  • Dronabinol / therapeutic use
  • Female
  • Fluorouracil / administration & dosage
  • Gastrointestinal Neoplasms / blood
  • Gastrointestinal Neoplasms / drug therapy*
  • Half-Life
  • Humans
  • Kinetics
  • Liver Neoplasms / blood
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / secondary
  • Male
  • Middle Aged
  • Semustine / administration & dosage


  • Semustine
  • 11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid
  • Dronabinol
  • Fluorouracil