Overview
DESCRIPTION Methoxsalen is a naturally occurring photoactive substance found in the seeds of the Ammi majus (Umbelliferae) plant. It belongs to a group of compounds known as psoralens or furocoumarins. The chemical name of methoxsalen is 9-methoxy-7H-furo[3,2-g][1]-benzopyran-7-one; it has the following structure: Each mL of UVADEX ® (methoxsalen, 8-methoxypsoralen) Sterile Solution contains...
Mechanism of Action
CLINICAL PHARMACOLOGY Mechanism of action The exact mechanism of action of methoxsalen is not known. The best-known biochemical reaction of methoxsalen is with DNA. Methoxsalen, upon photoactivation, conjugates and forms covalent bonds with DNA which leads to the formation of both monofunctional (addition to a single strand of DNA) and bifunctional adducts (crosslinking of psoralen to both strands of DNA). Reactions with proteins have also been described. The formation of photoadducts results in inhibition of DNA synthesis, cell division and epidermal turnover. For the palliative treatment of Cutaneous T-Cell Lymphoma, Photopheresis consists of removing a portion of the patient's blood and separating the red blood cells from the white cell layer (buffy coat) by centrifugation.
Indications
- INDICATIONS AND USAGE UVADEX ® (methoxsalen) Sterile Solution is indicated for extracorporeal administration with the THERAKOS ® CELLEX ® Photopheresis System in the palliative treatment of the skin manifestations of Cutaneous T-Cell Lymphoma (CTCL) that is unresponsive to other forms of treatment.
Common Doses
- 10 mL
- 200 mcg
- 20 mcg
- 240 mL
Dosage
DRUG DOSAGE AND ADMINISTRATION Each UVADEX ® treatment involves collection of leukocytes, photoactivation, and reinfusion of photoactivated cells. UVADEX ® (methoxsalen) Sterile Solution is supplied in 10 mL vials containing 200 mcg of methoxsalen (concentration of 20 mcg/mL). The THERAKOS ® CELLEX ® Photopheresis System Operator's Manual should be consulted before using this product. UVADEX ® should not be diluted. The contents of the vial should be injected into the THERAKOS ® CELLEX ® Photopheresis System immediately after being drawn up into a syringe. Do not inject directly into patients.
Black Box Warning
UVADEX ® (methoxsalen) Sterile Solution should be used only by physicians who have special competence in the diagnosis and treatment of cutaneous T-cell lymphoma and who have special training and experience in the THERAKOS ® CELLEX ® Photopheresis System. Please consult the CELLEX ® Operator's Manual before using this product.
Contraindications
- CONTRAINDICATIONS UVADEX ® (methoxsalen) Sterile Solution is contraindicated in patients exhibiting idiosyncratic or hypersensitivity reactions to methoxsalen, other psoralen compounds or any of the excipients. Patients possessing a specific history of a light sensitive disease state should not initiate methoxsalen therapy. Diseases associated with photosensitivity include lupus erythematosus, porphyria cutanea tarda, erythropoietic protoporphyria, variegate porphyria, xeroderma pigmentosum and albinism.
Side Effects
- ADVERSE REACTIONS Side effects of photopheresis (UVADEX ® used with THERAKOS ® Photopheresis Systems) were primarily related to hypotension secondary to changes in extracorporeal volume (>1%). In study CTCL 3 (UVADEX ® ), six serious cardiovascular adverse experiences were reported in five patients (5/51, 10%). Five of these six events were not related to photopheresis and did not interfere with the scheduled photopheresis treatments. One patient (1/51, 2%) with ischemic heart disease had an arrhythmia after the first day of photopheresis that was resolved the next day.
Interactions
- Drug Interactions See Warnings Section.