AMELUZ
Clinical safety rating: caution
Comprehensive clinical and safety monograph for AMELUZ (AMELUZ).
AMELUZ (aminolevulinic acid hydrochloride) is a photosensitizer that is converted to protoporphyrin IX (PpIX) in rapidly proliferating cells. Upon exposure to light of appropriate wavelength and intensity, PpIX generates reactive oxygen species, leading to phototoxicity and cell death in abnormal tissues.
| Metabolism | Aminolevulinic acid is metabolized intracellularly via the heme biosynthesis pathway to protoporphyrin IX (PpIX). It does not undergo significant hepatic metabolism; elimination occurs primarily via renal excretion. |
| Excretion | Primarily hepatic metabolism; <2% excreted unchanged in urine. Biliary/fecal excretion of metabolites accounts for the majority of elimination. |
| Half-life | Terminal elimination half-life is approximately 1-2 hours after topical application. Systemic exposure is minimal due to limited percutaneous absorption. |
| Protein binding | Primarily bound to albumin and α1-acid glycoprotein; binding is approximately 95%. |
| Volume of Distribution | Vd after topical application is not calculated due to negligible systemic absorption. Intravenous data in animal studies suggest a Vd of 0.5-1.0 L/kg, indicating distribution into total body water. |
| Bioavailability | Topical bioavailability is extremely low (<1%) due to minimal percutaneous absorption; systemic absorption is negligible. |
| Onset of Action | Clinical effect onset occurs within 2-4 weeks of daily topical application, as visible lesion clearance begins. |
| Duration of Action | Duration of action is not well-defined; treatment course is typically 4-6 weeks. Lesion clearance may continue for several weeks after treatment cessation. |
Apply one 30 g tube of AMELUZ (aminolevulinic acid hydrochloride) topical solution 10% to the lesion and surrounding 0.5 cm of normal skin once, followed by photodynamic therapy using red light (630 nm, 37 J/cm²) 14-18 hours later.
| Dosage form | GEL |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | No dose adjustment required for hepatic impairment. |
| Pediatric use | Safety and efficacy in pediatric patients have not been established; use is not recommended. |
| Geriatric use | No specific dose adjustment needed, but elderly patients may have increased photosensitivity; monitor for local skin reactions. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for AMELUZ (AMELUZ).
| Breastfeeding | Not known if aminolevulinic acid or its metabolites are excreted in human milk. Caution should be exercised when administered to a nursing woman. No M/P ratio available. Because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother. Topical use with minimal systemic absorption likely limits transfer. |
| Teratogenic Risk | FDA Pregnancy Category B. In animal studies, aminolevulinic acid (ALA) showed no evidence of teratogenicity in rats and rabbits at doses up to 6 times the human dose. There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, use during pregnancy only if clearly needed. However, ALA is a precursor of protoporphyrin IX (PpIX) and photosensitizer; theoretical risk of phototoxicity to fetus if uterus exposed to light. No specific first-trimester risks identified. |
■ FDA Black Box Warning
None
| Serious Effects |
["Cutaneous photosensitivity to porphyrins","Known hypersensitivity to aminolevulinic acid or any component of the formulation","Acute porphyria (including porphyria cutanea tarda)"]
| Precautions | ["Do not apply to open wounds or infected areas.","Avoid sunlight and bright indoor light for 48 hours after application.","Photosensitivity reactions including severe erythema, edema, and blistering may occur.","Use only under the supervision of a healthcare provider experienced in photodynamic therapy.","Not for ophthalmic, oral, or intravaginal use."] |
| Food/Dietary | No clinically significant food interactions. No dietary restrictions required. |
Loading safety data…
| Fetal Monitoring | No specific fetal monitoring recommended. Advise patients to avoid exposure of treated area to sunlight or bright indoor light (e.g., examination lamps, operating room lights, tanning beds) for at least 40 hours post-application. Monitor for local skin reactions: erythema, edema, burning, stinging, crusting, scaling, pruritus. No special maternal vital sign monitoring required. |
| Fertility Effects | No studies on fertility in humans. In animal studies, no effects on fertility or reproductive performance were observed in rats after oral administration of ALA at doses up to 6 times the human dose. Based on mechanism (photosensitization), no direct effect on gametes or reproductive organs expected with topical use. |
| Clinical Pearls |
| AMELUZ (aminolevulinic acid hydrochloride) is used for photodynamic therapy (PDT) of actinic keratoses. Apply evenly to lesions and surrounding 0.5 cm of normal skin. Avoid application to eyes or mucous membranes. Post-application, protect treated area from light (including sunlight, bright indoor lights) until after light treatment (16-18 hours later). The drug must be activated with blue light (BLU-U) for 16 minutes 40 seconds at the specified distance. Pain during light treatment is common; consider cooling, distraction, or topical anesthesia. Sunscreen and sun avoidance are critical post-treatment. |
| Patient Advice | Apply the solution to the skin lesions exactly as directed by your healthcare provider. · Avoid exposing the treated skin to sunlight, sunlamps, or bright indoor lights for 16-18 hours after application. · After the waiting period, you must return for a blue light treatment that will activate the medication. · You may experience stinging, burning, or redness during and after the light treatment; these effects are expected and temporary. · After treatment, the skin will be photosensitive for at least 40 hours; use sunscreen and protective clothing when going outdoors. · Do not apply the medication to broken skin, eyes, or mucous membranes. · Keep the medication away from children and pets. |