Irreversible H2-antagonism of the four isomeric butyl analogues of mifentidine

Agents Actions. 1990 Apr;30(1-2):166-8. doi: 10.1007/BF01969028.


It has been hypothesized that bidentate hydrogen bonding plays an important role in the interaction of imidazolylphenylformamidines with the H2-receptor. The present study, in which the degree of pseudo-irreversible H2-antagonism of the four isomeric butyl substituted mifentidine analogues was determined on the spontaneously beating right atrium of the male guinea-pig, lends further support to this hypothesis. In solution the EE/EZ ratio is different for the four isomeric butylated mifentidine analogues. The rank order of the percentage of E,E conformation, which favors a bidentate interaction, of the formamidine moiety parallels the rank order of pseudo-irreversible H2-antagonism.

MeSH terms

  • Animals
  • Chemical Phenomena
  • Chemistry, Physical
  • Guinea Pigs
  • Heart / drug effects
  • Histamine H2 Antagonists / pharmacology*
  • Imidazoles / pharmacology*
  • In Vitro Techniques
  • Male
  • Molecular Conformation


  • Histamine H2 Antagonists
  • Imidazoles
  • mifentidine