Metvix (Methyl Aminolevulinate)

Metvix is a topical photosensitizer used in photodynamic therapy for precancerous and early skin cancers.

• Actinic keratosis: clears precancerous lesions by inducing selective cytotoxicity after red‑light activation, reducing progression to squamous cell carcinoma.
• Superficial basal cell carcinoma: eradicates superficial skin cancer cells through targeted photodynamic treatment, offering a non‑surgical alternative for eligible lesions.
• Photodynamic therapy of skin lesions: enables controlled destruction of abnormal skin tissue while preserving healthy surrounding skin, suitable for various dysplastic lesions.

• The methyl aminolevulinate in Metvix penetrates keratinocytes and is enzymatically converted to protoporphyrin IX, a potent photosensitizer. Upon exposure to red light of a specific wavelength, protoporphyrin IX generates reactive oxygen species that cause oxidative damage and selective cytotoxicity of abnormal or neoplastic skin cells, while sparing normal tissue.

The most frequently reported reactions to Metvix are related to local skin response and illumination.

Common Side Effects

• Erythema: redness at the application site.
• Edema: swelling of the treated area.
• Pain or burning sensation during or after illumination.
• Crusting or scaling of the skin.
• Itching or pruritus.
• Hyperemia.

Serious or Rare Side Effects

• Severe photosensitivity reactions extending beyond the treated field.
• Infection of the treated area requiring medical intervention.
• Allergic contact dermatitis.
• Persistent ulceration or scarring.
• Hyperpigmentation or hypopigmentation.
• Systemic phototoxicity in rare cases.

Before using Metvix, healthcare professionals should consider several safety measures to minimize adverse outcomes.

• Light exposure: avoid direct sunlight or strong artificial light on treated area for at least 48 hours after illumination.
• Application area: limit use to diagnosed lesions and follow prescribed treatment field dimensions.
• Patient selection: exercise caution in immunocompromised patients or those with extensive skin disease.
• Pregnancy and lactation: safety not established; avoid use unless benefit outweighs potential risk.
• Concomitant photosensitizing agents: review patient medications and discontinue or adjust as appropriate.
• Store at below 25°C: keep the cream in the original container, protect from moisture and light.

Metvix may interact with other agents that influence photosensitivity or skin healing.

Major Interactions (Avoid)

• Tetracycline antibiotics (e.g., doxycycline): increase risk of severe photosensitivity.
• Oral retinoids (e.g., isotretinoin): enhance skin irritation and phototoxic response.
• Phenothiazine antipsychotics (e.g., chlorpromazine): potentiate photosensitivity.
• Amiodarone: may cause exaggerated phototoxic reactions.
• St. John’s wort: can increase photosensitivity.

Moderate Interactions (Monitor Closely)

• Topical corticosteroids: may reduce efficacy of photodynamic treatment if applied immediately after therapy.
• Systemic chemotherapy agents: may impair wound healing and increase risk of infection at treatment sites.