Aminolevulinic acid

U.S. BRAND NAMES — Levulan® Kerastick®

PHARMACOLOGIC CATEGORY
Photosensitizing Agent, Topical
Topical Skin Product

DOSING: ADULTS — Actinic keratoses: Topical: Apply to actinic keratoses (not perilesional skin) followed 14-18 hours later by blue light illumination. Application/treatment may be repeated at a treatment site after 8 weeks.

DOSING: ELDERLY — Refer to adult dosing.

DOSAGE FORMS — Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Powder for topical solution:
Levulan® Kerastick®: 20% (6s) [2-component system containing aminolevulinic acid hydrochloride 354 mg (powder) and diluent containing ethanol 48% (1.5 mL) packaged together in an applicator tube]

DOSAGE FORMS: CONCISE
Powder for topical solution:
Levulan® Kerastick®: 20% (6s)

GENERIC EQUIVALENT AVAILABLE — No

ADMINISTRATION — Dab lesion gently with wet applicator tip. Do not apply to periorbital area, ocular tissue, or mucosal surfaces. Allow to dry, then reapply to same lesion. Apply to either scalp or facial lesions, but not to both simultaneously. Follow application with blue light exposure in 14-18 hours.

USE — Treatment of minimally to moderately thick actinic keratoses (grade 1 or 2) of the face or scalp; to be used in conjunction with blue light illumination

ADVERSE REACTIONS SIGNIFICANT — Transient stinging, burning, itching, erythema, and edema result from the photosensitizing properties of this agent. Symptoms subside between 1 minute and 24 hours after turning off the blue light illuminator. Severe stinging or burning was reported in at least 50% of patients from at least 1 lesional site treatment.

>10%: Dermatologic: Severe stinging or burning (50%), scaling of the skin/crusted skin (64% to 71%), hyper-/hypopigmentation (22% to 36%), itching (14% to 25%), erosion (2% to 14%)

1% to 10%:
Central nervous system: Dysesthesia (up to 2%)
Dermatologic: Skin ulceration (2% to 4%), vesiculation (4% to 5%), pustular drug eruption (up to 4%), skin disorder (5% to 12%)
Hematologic: Bleeding/hemorrhage (2% to 4%)
Local: Wheal/flare (2% to 7%), local pain (1%), tenderness (1% to 2%), edema (1%), scabbing (up to 2%), ulceration (2% to 4%), excoriation (1%)

CONTRAINDICATIONS — Hypersensitivity to aminolevulinic acid or any component of the formulation; individuals with cutaneous photosensitivity at wavelengths of 400-450 nm; porphyria; allergy to porphyrins

WARNINGS / PRECAUTIONS — For external use only. Do not apply to eyes or mucous membranes. Treatment site will become photosensitive following application. Patients should be instructed to avoid exposure to sunlight, bright indoor lights, or tanning beds during the period prior to blue light treatment. Should be applied by a qualified health professional to avoid application to perilesional skin. Has not been tested in individuals with coagulation defects (acquired or inherited).

DRUG INTERACTIONS — Photosensitizing agents including griseofulvin, thiazide diuretics, sulfonamides, sulfonylureas, phenothiazines, and tetracyclines theoretically may increase the photosensitizing potential of aminolevulinic acid.

PREGNANCY RISK FACTOR — C (show table)

PREGNANCY IMPLICATIONS — Animal reproduction studies have not been conducted, and there are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if clearly needed.

LACTATION — Excretion in breast milk unknown/use caution

TOXICOLOGY / OVERDOSE COMPREHENSIVE — Monitoring and supportive care are recommended. Patients should be advised to avoid incidental exposure to intense light sources for at least 40 hours. Consequences of exceeding the recommended topical dosage are not known.

CANADIAN BRAND NAMES — Levulan®

INTERNATIONAL BRAND NAMES — Levulan (CA)

MECHANISM OF ACTION — Aminolevulinic acid is a metabolic precursor of protoporphyrin IX (PpIX), which is a photosensitizer. Photosensitization following application of aminolevulinic acid topical solution occurs through the metabolic conversion to PpIX. When exposed to light of appropriate wavelength and energy, accumulated PpIX produces a photodynamic reaction.

PHARMACODYNAMICS / KINETICS
PpIX:
Peak fluorescence intensity: 11 hours +/- 1 hour
Half-life, mean clearance for lesions: 30 +/- 10 hours

PATIENT INFORMATION — Solution will be applied by prescriber. Once solution is applied, affected skin will be sensitive to light. Wear protective clothing when exposed to light and avoid bright lights (including tanning beds) and sunlight. Sunscreens will not prevent phototoxic reactions. Solution will be applied directly to lesions; blue light exposure should follow 14-18 hours later. Do not wash solution off skin during this time. If you are not able to return for blue light therapy, avoid sunlight and other bright light for at least 40 hours following application of solution.