Novel bioactive metabolites of dipyrone (metamizol)

Bioorg Med Chem. 2012 Jan 1;20(1):101-7. doi: 10.1016/j.bmc.2011.11.028. Epub 2011 Nov 25.

Abstract

Dipyrone is a common antipyretic drug and the most popular non-opioid analgesic in many countries. In spite of its long and widespread use, molecular details of its fate in the body are not fully known. We administered dipyrone orally to mice. Two unknown metabolites were found, viz. the arachidonoyl amides of the known major dipyrone metabolites, 4-methylaminoantipyrine (2) and 4-aminoantipyrine (3). They were identified by ESI-LC-MS/MS after extraction from the CNS, and comparison with reference substances prepared synthetically. The arachidonoyl amides were positively tested for cannabis receptor binding (CB(1) and CB(2)) and cyclooxygenase inhibition (COX-1 and COX-2 in tissues and as isolated enzymes), suggesting that the endogenous cannabinoid system may play a role in the effects of dipyrone against pain.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Aminopyridines / chemistry
  • Ampyrone / chemistry
  • Animals
  • Central Nervous System / chemistry
  • Chromatography, High Pressure Liquid / standards
  • Cyclooxygenase 1 / chemistry
  • Cyclooxygenase 1 / metabolism
  • Cyclooxygenase 2 / chemistry
  • Cyclooxygenase 2 / metabolism
  • Cyclooxygenase Inhibitors / chemistry
  • Cyclooxygenase Inhibitors / pharmacology
  • Dipyrone / metabolism*
  • Dipyrone / pharmacology
  • Enzyme Activation / drug effects
  • Mice
  • Mice, Inbred C57BL
  • Receptor, Cannabinoid, CB1 / metabolism
  • Receptor, Cannabinoid, CB2 / metabolism
  • Reference Standards
  • Spectrometry, Mass, Electrospray Ionization / standards

Substances

  • Aminopyridines
  • Cyclooxygenase Inhibitors
  • Receptor, Cannabinoid, CB1
  • Receptor, Cannabinoid, CB2
  • Ampyrone
  • 4-methylaminopyridine
  • Dipyrone
  • Cyclooxygenase 1
  • Cyclooxygenase 2