Generic name: methoxsalen
Drug class: Psoralens
Medically reviewed by A Ras MD.
What is Uvadex?
Uvadex is a prescription medicine that is used to treat a type of lymphoma that affects the skin.
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]-benzopyran-7-one; it has the following structure:
Each mL of UVADEX® (methoxsalen, 8-methoxypsoralen) Sterile Solution contains methoxsalen 20 mcg, propylene glycol 50 mg, sodium chloride 8 mg, sodium acetate 1.75 mg, ethanol 40.550 mg, glacial acetic acid 1.260 mg, and Water for Injection q.s. to 1.0 mL. Glacial acetic acid and sodium hydroxide are used to adjust the pH of the solution if necessary. UVADEX® is a clear, colorless to pale yellow liquid.
UVADEX® is used in combination with the THERAKOS® CELLEX® Photopheresis System to extracorporeally treat leukocyte enriched buffy coat.
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. The red cells are returned to the patient and the UVADEX® Sterile Solution is then injected into the instrument and mixed with the buffy coat. The instrument then irradiates this drug-cell mixture with ultraviolet light (UVA light, 320–400 nm) and returns the treated cells to the patient. See the appropriate Operator’s Manual for details of this process. Although extracorporeal phototherapy exposes less than 10% of the total body burden of malignant cells to methoxsalen plus light, some patients achieve a complete response. Animal studies suggest that the photopheresis may activate an immune-mediated response against the malignant T-cells.
Use of the THERAKOS® UVAR and UVAR XTS® Photopheresis Systems after oral administration of methoxsalen were previously approved for the treatment of Cutaneous T-Cell Lymphoma. Interpatient variability in peak plasma concentration after an oral dose of methoxsalen ranges from 6 to 15 fold. UVADEX® is injected directly into the separated buffy coat in the instrument in an attempt to diminish this interpatient variability and to improve the exposure of the cells to the drug.
Methoxsalen is reversibly bound to serum albumin and is also preferentially taken up by epidermal cells. Methoxsalen is rapidly metabolized in humans, with approximately 95% of the drug excreted as metabolites in the urine within 24 hours.
Systemic administration of methoxsalen followed by UVA exposure leads to cell injury. The most obvious manifestation of this injury after skin exposure is delayed erythema, which may not begin for several hours and peaks at 48–72 hours. The inflammation is followed over several days to weeks, by repair which is manifested by increased melanization of the epidermis and thickening of the stratum corneum.
The total dose of methoxsalen delivered in UVADEX® is substantially lower (approximately 200 times) than that used with oral administration. More than 80% of blood samples collected 30 minutes after reinfusion of the photoactivated buffy coat had methoxsalen levels below detection limits of the assay (<10 ng/ml), and the mean plasma methoxsalen concentration was approximately 25 ng/ml.
Before taking Uvadex, tell your doctor:
- If you are allergic to Uvadex; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
- If you have any of these health problems: Squamous cell cancer or if you do not have a lens in your eye (aphakia).
- If you have ever had melanoma.
- If light bothers your skin easily or you have a health problem that may lead to light bothering your skin. There are many health problems that can do this. Ask your doctor or pharmacist if you are not sure.
This is not a list of all drugs or health problems that interact with this medicine.
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Uvadex with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Uvadex?
- Tell all of your health care providers that you take Uvadex. This includes your doctors, nurses, pharmacists, and dentists.
- Have blood work checked as you have been told by the doctor. Talk with the doctor.
- Have an eye exam as you have been told by your doctor.
- Do not sunbathe within 24 hours before taking Uvadex and the light therapy. Talk with your doctor.
- You will need to wear special sunglasses during and for 24 hours after treatment. Protect lips with lipstick that has sunscreen.
- Do not take Uvadex for longer than you were told by your doctor.
- Sun or UV rays may age the skin and raise the chance of skin cancer.
- You may get sunburned more easily. Avoid sun, sunlamps, and tanning beds. Use sunscreen and wear clothing and eyewear that protects you from the sun. Keep protecting yourself from sunburn for as long as you were told by your doctor.
- Talk with your doctor before you use other drugs or products on your skin.
- Blood clots have happened with Uvadex when used to treat graft-versus-host disease. This medicine is not approved to treat graft-versus-host disease. If you have questions, talk with your doctor.
- If you are 65 or older, use Uvadex with care. You could have more side effects.
- This medicine may cause harm to an unborn baby. Women must use birth control while taking Uvadex. If you get pregnant, call your doctor right away.
- Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.
How is Uvadex best taken?
Use Uvadex as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- This medicine is used with a special system called a photophoresis system. This will be done by your doctor. Talk with your doctor if you have any questions.
What do I do if I miss a dose?
- Call your doctor to find out what to do.
What are the side effects of Uvadex that I need to call my doctor about immediately?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Change in color or size of a mole.
- Low mood (depression).
- A skin lump or growth.
- Very bad dizziness or passing out.
- Change in eyesight.
What are some other side effects of Uvadex?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Skin irritation.
- Upset stomach.
- Feeling nervous and excitable.
- Trouble sleeping.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
If overdose is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Uvadex?
- If you need to store Uvadex at home, talk with your doctor, nurse, or pharmacist about how to store it.
PRINCIPAL DISPLAY PANEL – 10 ML VIAL CARTON
- NDC 64067-216-01
(Methoxsalen) Sterile Solution 10 mL
SRC: NLM .