Use of thermospray liquid chromatography-mass spectrometry to aid in the identification of urinary metabolites of a novel antiepileptic drug, Lamotrigine

J Chromatogr. 1991 Aug 21;554(1-2):181-9. doi: 10.1016/s0021-9673(01)88448-x.


The use of thermospray liquid chromatography-mass spectrometry allowed the structural elucidation of a number of urinary metabolites of Lamotrigine, 3,5-diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine, formed after administering the drug to man, Cynomolgus monkey and rabbit. This data when combined with the data obtained from high-performance liquid chromatography with radiochemical detection enabled us to determine the types and amounts of unchanged drug and metabolites excreted in urine by man and a number of laboratory animal species. This technique was particularly useful as it highlighted a previously unknown fact that Lamotrigine is metabolised to form two different N-glucuronides, one of which is resistant to cleavage in vitro by a crude beta-glucuronidase preparation from Helix pomatia.

MeSH terms

  • Animals
  • Anticonvulsants / urine*
  • Carbon Radioisotopes
  • Chromatography, Liquid / methods*
  • Glucuronates / urine
  • Humans
  • Lamotrigine
  • Macaca fascicularis
  • Mass Spectrometry / methods*
  • Rabbits
  • Triazines / urine*


  • Anticonvulsants
  • Carbon Radioisotopes
  • Glucuronates
  • Triazines
  • Lamotrigine