Drug Interaction Report

GENERALLY AVOID: Patients exposed to photosensitizing agents around the same time as oral aminolevulinic acid may be at an increased risk of a phototoxic skin reaction (severe sunburn). These agents have each been individually associated with photosensitivity reactions and may have additive effects when used together. Medicinal products with known phototoxic or photoallergic potential include, but are not limited to, hypericin-containing products (e.g., St. John's Wort), griseofulvin, thiazide diuretics, sulfonylureas, phenothiazines, sulfonamides, quinolones, tetracyclines, and topical aminolevulinate preparations. There is one case report of a severe sunburn lasting for 5 days in a patient who used oral aminolevulinic acid concurrently with a hypericin extract.

MANAGEMENT: Photosensitizing agents (e.g., fluoroquinolones, phenothiazines, retinoids, sulfonamides, sulfonylureas, tetracyclines, thiazide diuretics, griseofulvin, St. John's wort) and topical preparations containing aminolevulinic acid should be avoided for 24 hours before and after oral administration of aminolevulinic acid. Some authorities recommend avoiding exposure to any photosensitizing agent for up to 2 weeks after oral administration of aminolevulinic acid. Patients should also avoid exposure of the eyes and skin to sunlight and bright indoor lights (e.g., examination lamps, operating room lamps, tanning beds, lights at close proximity) for 48 hours after treatment.

ADJUST DOSING INTERVAL: Food reduces the oral absorption and bioavailability of voriconazole. According to the product labeling, administration of multiple doses of voriconazole with high-fat meals decreased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) by 34% and 24%, respectively, when the drug is administered as a tablet, and by 58% and 37%, respectively, when administered as the oral suspension.

MANAGEMENT: To ensure maximal oral absorption, voriconazole tablets and oral suspension should be taken at least one hour before or after a meal.