METVIXIA
Clinical safety rating: caution
Comprehensive clinical and safety monograph for METVIXIA (METVIXIA).
Metvixia (methyl aminolevulinate) is a photosensitizer. It is converted intracellularly into protoporphyrin IX (PpIX), which accumulates preferentially in neoplastic cells. Subsequent exposure to light (photodynamic therapy) activates PpIX, producing reactive oxygen species that cause cellular damage and apoptosis.
| Metabolism | Methyl aminolevulinate is metabolized intracellularly via the heme biosynthesis pathway to protoporphyrin IX; systemic metabolism is minimal. |
| Excretion | Primarily via hepatic metabolism; negligible renal excretion (<1%). Fecal elimination of unchanged drug is minimal. |
| Half-life | 20-30 minutes for plasma clearance; clinically, photosensitivity peaks at 2-4 hours and resolves within 24-48 hours. |
| Protein binding | Highly protein bound (>90%) to albumin and other plasma proteins. |
| Volume of Distribution | Apparent Vd ~5 L/kg, indicating extensive tissue distribution but limited clinical relevance due to topical use. |
| Bioavailability | Topical: negligible systemic absorption (<1% of applied dose); oral: not applicable. |
| Onset of Action | Topical application: skin fluorescence detectable within 1 hour; maximal photodynamic effect at 3-4 hours. |
| Duration of Action | Effective photosensitivity lasts up to 48 hours; treatment area should be protected from light for at least 48 hours. |
16.1% methyl aminolevulinate cream applied topically to lesion and surrounding 5 mm of normal skin, covered with occlusive dressing for 3 hours, then removed and lesion exposed to red light (570-670 nm, 37 J/cm², 8-10 minutes) after cleansing; repeat after 1 week. Maximum treated area: 2 lesions per session.
| Dosage form | CREAM |
| Renal impairment | No dose adjustment required as systemic absorption is negligible (<0.5% of applied dose) and no renal excretion of parent drug. |
| Liver impairment | No dose adjustment required due to negligible systemic absorption; photosensitizer is locally activated and virtually no hepatic metabolism occurs. |
| Pediatric use | Not recommended for use in pediatric patients due to lack of safety and efficacy data; contraindicated for treatment of actinic keratosis or basal cell carcinoma in children. |
| Geriatric use | No specific dose adjustment needed; same dosing as adults based on clinical studies including patients aged 65 and older with comparable safety and efficacy. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for METVIXIA (METVIXIA).
| Breastfeeding | Unknown if excreted in human milk. M/P ratio not established. Due to potential for phototoxicity, caution advised; consider discontinuing breastfeeding or avoiding use. |
| Teratogenic Risk | No evidence of teratogenicity in animal studies. In humans, no adequate studies; theoretical risk of fetal phototoxicity if systemic absorption occurs. Avoid in pregnancy unless benefit outweighs risk. |
| Fetal Monitoring |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
["Hypersensitivity to methyl aminolevulinate or any component of the formulation","Porphyria (due to accumulation of porphyrins)","Pregnancy (Category C; not recommended unless benefit outweighs risk)","Breastfeeding (not recommended)"]
| Precautions | ["Photosensitivity: avoid sun exposure and bright indoor light for 48 hours after application.","Local skin reactions: severe erythema, edema, or ulceration may occur; treat symptomatically.","Use only for lesions within the specified treatment area; do not apply to mucous membranes or eyes.","Not evaluated for lesions on the trunk or extremities.","Carcinogenicity: repeated use may increase risk of skin cancer; monitor patients long-term."] |
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| Monitor for local skin reactions, photosensitivity. No specific fetal monitoring required; routine prenatal care. |
| Fertility Effects | No known effects on fertility in animal studies. Human data lacking. |