Drug Interactions Newsletter

Volume 1, Issue 6, 02/24/2009

Question

How can the use of proton pump inhibitors (i.e., omeprazole, lansoprazole) significantly decrease the absorption of itraconazole (Sporanox) thereby increasing the risk of antifungal treatment failure?

Answer

The triazole antifungal medication, itraconazole (Sporanox®) is used for the treatment of both superficial and systemic fungal infections.  Successful treatment of systemic or invasive fungal infections is dependent on consistent plasma itraconazole levels.(1-3)  Unfortunately, the encapsulated formulation of itraconazole has been associated with wide variability in plasma concentrations due to variability in absorption in the gastrointestinal (GI) tract.  This variability can be exaggerated by coadministration with antacids or proton pump inhibitors (PPI; e.g.., omeprazole, lansoprazole, pantoprazole)(4) Fortunately, this is not the case with the oral solution or intravenous (IV) formulations of itraconazole.  So why is there such variability in  absorption with the encapsulated form of itraconazole?......To read the full answer please LOGIN or SUBSCRIBE NOW.