Acute hyperosmolar hyperglycaemic state in cystic fibrosis-related diabetes caused by glucocorticoid and itraconazole interaction.

Hyperosmolar hyperglycaemic state (HHS) has not previously been reported in cystic fibrosis-related diabetes (CFRD). We report the case of a 15-year old boy with stable CFRD who developed acute HHS after treatment with glucocorticoids and itraconazole for presumed allergic broncho-pulmonary aspergillosis (ABPA). This case highlights the dangerous and preventable combination of high glucose intake, glucocorticoids and itraconazole inhibition of CYP3A4 (with resultant glucocorticoid accumulation) that can result in a state of life- threatening HHS in an adolescent with previously stable CFRD.