Identify a common drug interaction associated with fluconazole.

Fluconazole is known to interact with warfarin, a commonly used anticoagulant. The interaction occurs because fluconazole can inhibit the cytochrome P450 enzyme system, particularly CYP2C9, which is responsible for the metabolism of warfarin. When fluconazole is administered, it can increase the plasma concentration of warfarin, potentially leading to an elevated International Normalized Ratio (INR) and an increased risk of bleeding.

Monitoring INR levels is crucial when initiating or discontinuing fluconazole in patients who are also on warfarin therapy to prevent adverse effects associated with over-anticoagulation. This interaction highlights the importance of understanding the metabolic pathways of drugs and the potential implications for patient safety when managing combination therapy.