Drug Interaction Report

MONITOR: Concomitant use of aminolevulinate topical preparations with other known photosensitizing agents may enhance the phototoxic reaction to photodynamic therapy. These agents have each been individually associated with photosensitivity reactions and may have additive effects if administered concurrently. Medicinal products with known phototoxic or photoallergic potential include fluoroquinolones, phenothiazines, retinoids, sulfonamides, sulfonylureas, tetracyclines, thiazide diuretics, griseofulvin, and hypericin extracts (e.g., St John's Wort).

MANAGEMENT: Caution is advised and pharmacologic response to photodynamic therapy should be carefully monitored if concomitant use of other photosensitizing agents cannot be avoided. Patients should be advised to avoid exposure of treated areas to sunlight or bright indoor lights (e.g., examination lamps, operating room lamps, tanning beds, lights at close proximity) during the period between application of aminolevulinic acid or methyl aminolevulinate and photoactivation, and for 48 hours post-illumination. As sunscreen is not effective in protecting treated areas of skin, patients should be counseled to wear protective apparel, such as a wide-brimmed hat, long sleeve shirt, and gloves to protect themselves. Concomitant use with other topical medicinal products should be avoided. Some authorities recommend avoiding use of hypericin-containing products for 2 weeks prior to treatment with topical aminolevulinic acid.

CONTRAINDICATED: Ethanol consumption with acitretin leads to the formation of etretinate, which has a much longer half-life than acitretin. Major human fetal abnormalities have been associated with the administration of acitretin, etretinate, and other retinoids. The longer elimination half-life of etretinate relative to acitretin increases the duration of teratogenic potential for female patients. In one case report of a patient with apparent sporadic ethanol intake, etretinate was present in plasma and fat for 52 months after acitretin was discontinued.

MANAGEMENT: Female patients should be warned that ethanol is contraindicated during active treatment with acitretin and for two months after cessation of therapy.