Which of the following is a potential drug interaction with azole antifungals?

Azole antifungals, such as fluconazole and itraconazole, are known to inhibit certain cytochrome P450 enzymes, particularly CYP2C19 and CYP3A4, which play a significant role in the metabolism of many medications. This inhibition can lead to increased plasma concentrations of co-administered drugs that are metabolized by these enzymes, potentially enhancing their effects or toxicity.

The interaction with warfarin is particularly important because azole antifungals can increase the anticoagulant effect of warfarin by inhibiting its metabolism. This results in an increased risk of bleeding, making monitoring of INR (International Normalized Ratio) essential in patients who are prescribed both warfarin and azole antifungals.

In contrast, while acetaminophen and opioids may have their own safety profiles, they do not interact directly with azole antifungals in a significant manner regarding metabolism through the same pathways. The efficacy of beta-blockers generally remains unaffected by azole antifungals in clinical practice, and the absorption of opioids is not decreased by these antifungals.

This makes the interaction between azole antifungals and warfarin a critical and clinically relevant consideration in pharmacotherapy.