Erythromycin breath test and clinical transplantation

Ther Drug Monit. 1996 Aug;18(4):368-71. doi: 10.1097/00007691-199608000-00009.


The intravenous 14C-erythromycin breath test (ERMBT) appears to be a convenient and reproducible means of measuring the activity of a major drug-metabolizing enzyme present in the liver, termed CYP3A4. Interpatient differences in liver CYP3A4 activity, as measured by the ERMBT, seem to account, for the most part, for interindividual differences in the kinetics of cyclosporin A and FK506. The predictability of the test may be improved as an oral form of the test and improved oral formulations of transplant medications are developed. Although the ERMBT is a promising research tool, its role in clinical transplantation has yet to be defined.

MeSH terms

  • Breath Tests / methods
  • Carbon Dioxide / metabolism
  • Carbon Radioisotopes
  • Cyclosporine / pharmacokinetics*
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme System / metabolism*
  • Erythromycin*
  • Genetic Variation
  • Humans
  • Liver / enzymology*
  • Liver / metabolism
  • Mixed Function Oxygenases / metabolism*
  • Organ Transplantation
  • Protein Synthesis Inhibitors*


  • Carbon Radioisotopes
  • Protein Synthesis Inhibitors
  • Carbon Dioxide
  • Erythromycin
  • Cyclosporine
  • Cytochrome P-450 Enzyme System
  • Mixed Function Oxygenases
  • CYP3A protein, human
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human