Selective induction of human hepatic cytochromes P450 2B6 and 3A4 by metamizole

Clin Pharmacol Ther. 2007 Sep;82(3):265-74. doi: 10.1038/sj.clpt.6100138. Epub 2007 Mar 7.

Abstract

The pyrazolone drug metamizole is a widely used analgesic. Analysis of liver microsomes from patients treated with metamizole revealed selectively higher expression of cytochromes P450, CYP2B6 and CYP3A4 (3.8- and 2.8-fold, respectively), and 2.9-fold higher bupropion hydroxylase activity compared with untreated subjects. Further investigation of metamizole and various derivatives on different potential target genes in human primary hepatocytes demonstrated time- and concentration-dependent induction by metamizole of CYP2B6 (7.8- and 3.1-fold for mRNA and protein, respectively, at 100 muM) and CYP3A4 (2.4- and 2.9-fold, respectively), whereas other genes (CYP2C9, CYP2C19, CYP2D6, NADPH:cytochrome P450 reductase, ABCB1, constitutive androstane receptor (CAR), pregnane X receptor (PXR)) were not substantially altered. Using reporter gene assays, we show that metamizole is not acting as a direct ligand to either PXR or CAR, suggesting a phenobarbital-like mechanism of induction. These data warrant further studies to elucidate the drug-interaction potential of metamizole, especially in patients with long-term treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Aryl Hydrocarbon Hydroxylases / biosynthesis*
  • Aryl Hydrocarbon Hydroxylases / genetics
  • Blotting, Western
  • Catalysis
  • Cells, Cultured
  • Constitutive Androstane Receptor
  • Cytochrome P-450 CYP2B6
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme System / biosynthesis*
  • Cytochrome P-450 Enzyme System / genetics
  • DNA / biosynthesis
  • DNA / genetics
  • Dipyrone / analogs & derivatives
  • Dipyrone / pharmacology*
  • Dose-Response Relationship, Drug
  • Enzyme Induction / drug effects
  • Female
  • Genotype
  • Hepatocytes / drug effects
  • Humans
  • In Vitro Techniques
  • Isoenzymes / metabolism
  • Liver / drug effects
  • Liver / enzymology
  • Male
  • Microsomes, Liver / drug effects
  • Microsomes, Liver / enzymology
  • Middle Aged
  • Oxidoreductases, N-Demethylating / biosynthesis*
  • Oxidoreductases, N-Demethylating / genetics
  • Plasmids
  • Pregnane X Receptor
  • RNA / biosynthesis
  • RNA / genetics
  • Receptors, Cytoplasmic and Nuclear / drug effects
  • Receptors, Steroid / drug effects
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcription Factors / drug effects

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Constitutive Androstane Receptor
  • Isoenzymes
  • Pregnane X Receptor
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Steroid
  • Transcription Factors
  • RNA
  • Dipyrone
  • DNA
  • Cytochrome P-450 Enzyme System
  • Aryl Hydrocarbon Hydroxylases
  • CYP2B6 protein, human
  • Cytochrome P-450 CYP2B6
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human
  • Oxidoreductases, N-Demethylating