An unusual cause of growth failure in cystic fibrosis: A salutary reminder of the interaction between glucocorticoids and cytochrome P450 inhibiting medication

J Cyst Fibros. 2015 Jul;14(4):e9-11. doi: 10.1016/j.jcf.2014.09.007. Epub 2014 Oct 5.


A 12 ½ year old male with cystic fibrosis presented with growth failure after itraconazole was added to a treatment regimen including inhaled and intranasal glucocorticoids. Investigations showed severe adrenal suppression. This case demonstrates the potential for exogenous glucocorticoids to accumulate when their degradation is inhibited by a CYP3A4 inhibitor.

Keywords: Adrenal suppression; Cystic fibrosis; Glucocorticoid; Growth failure; Itraconazole.

Publication types

  • Case Reports

MeSH terms

  • Child
  • Cystic Fibrosis / drug therapy*
  • Cytochrome P-450 CYP3A Inhibitors / administration & dosage
  • Cytochrome P-450 CYP3A Inhibitors / adverse effects*
  • Drug Interactions
  • Glucocorticoids / administration & dosage
  • Glucocorticoids / adverse effects*
  • Growth Disorders / etiology*
  • Humans
  • Itraconazole / administration & dosage
  • Itraconazole / adverse effects*
  • Male


  • Cytochrome P-450 CYP3A Inhibitors
  • Glucocorticoids
  • Itraconazole