Pharmacokinetics and biotransformation studies of terfenadine in man

Arzneimittelforschung. 1982;32(9a):1185-90.


Comparison of plasma level data obtained from a dose-response study to that of a 14C material balance study indicates that 99.48% of the alpha-[4-(1,1-dimethylethyl)phenyl] 4-(hydroxydiphenylmethyl)-1-piperidinebutanol (terfenadine, RMI 9918, Triludan, Teldane, resp.) related material absorbed undergoes biotransformation. From the balance study it has been determined that fecal excretion accounts for ca. 60% of the dose administered. Thin-layer chromatographic analysis of urine and feces revealed the presence of two major metabolic products. These compounds have been isolated and their structures determined by GC-MS. One of the metabolic products, a carboxylic acid analog of terfenadine has been shown to have antihistaminic activity and may play a role in the activity of the parent drug in vivo.

MeSH terms

  • Benzhydryl Compounds / metabolism*
  • Biological Availability
  • Biotransformation
  • Dose-Response Relationship, Drug
  • Feces / analysis
  • Gas Chromatography-Mass Spectrometry
  • Humans
  • Kinetics
  • Male
  • Radioimmunoassay
  • Terfenadine


  • Benzhydryl Compounds
  • Terfenadine