methoxsalen at a glance
Medicine class
Photosensitising psoralen with antineoplastic and immunomodulating effects
Licensed role
Specialist photopheresis for skin manifestations of advanced cutaneous T-cell lymphoma after inadequate response to other treatment
How it is given
Added outside the body to a separated white-cell-rich blood fraction; it must not be injected directly or taken at home
Light protection
Wrap-around UVA-blocking sunglasses are required during treatment and afterwards; avoid sunlight afterwards
What is methoxsalen used for?
The selected product is licensed only for specialist extracorporeal use.
Palliative treatment of patch, extensive plaque or erythrodermic skin manifestations of advanced cutaneous T-cell lymphoma when other treatments have not produced an adequate response.
Specialist services also use methoxsalen-containing extracorporeal photopheresis for graft-versus-host disease. This is outside the selected product's licensed indication.
How does methoxsalen work?
Methoxsalen enters separated white cells and becomes active when exposed to UVA light. It forms cross-links in cellular DNA, stopping affected lymphocytes from multiplying and promoting programmed cell death. Reinfusion of treated cells is also thought to modify immune responses, although the complete mechanism remains uncertain.
How to take methoxsalen
Methoxsalen is given only by a trained specialist team during extracorporeal photopheresis. Blood is separated, the white-cell-rich fraction is mixed with methoxsalen and exposed to UVA light, and the treated blood is returned. Follow the unit's instructions about food, fluids and regular medicines. Wear specified wrap-around UVA-blocking sunglasses and protect skin from sunlight afterwards. Do not drive or operate machinery immediately after treatment.
Bring an up-to-date list of medicines and approved protective sunglasses to appointments.
Tell staff promptly if you feel faint, dizzy, feverish or unwell during the procedure.
Do not attempt to inject, swallow or otherwise administer the solution yourself.
methoxsalen side effects
Common or expected effects
- Low blood pressure, which may cause dizziness or weakness
- Nausea or vomiting
- Temporary fever
- Infection
- Altered taste
- Bruising, vein damage or other vascular-access complications
Get urgent medical advice
- Allergic reaction, particularly swelling, breathing difficulty or collapse
- Severe or persistent low blood pressure or fainting
- Serious infection or sepsis
- Marked photosensitivity or a significant skin burn after light exposure
methoxsalen in pregnancy
The selected product is contraindicated during pregnancy because human experience is lacking and animal evidence suggests possible fetal harm. Tell the specialist team before treatment if you are pregnant, may be pregnant or are planning pregnancy. Effective contraception is required for treated men and women during treatment and afterwards; the specialist should advise on the method and period.
methoxsalen while breastfeeding
The selected product is contraindicated while breastfeeding. It is unknown whether methoxsalen enters human milk, so discuss feeding options with the specialist team before treatment.
methoxsalen interactions
Give the photopheresis team a complete list of prescribed, non-prescription and topical products. Interactions can affect methoxsalen metabolism or add to light sensitivity.
Phenytoin
May increase methoxsalen metabolism and reduce the effectiveness of photochemotherapy.
Tolbutamide
Can displace methoxsalen from protein binding and increase photosensitivity.
Photosensitising medicines
Fluoroquinolones, tetracyclines, sulfonamides, thiazides, furosemide, phenothiazines and retinoids may increase sensitivity to UVA or sunlight.
Common questions about methoxsalen
Answers are fully visible for fast scanning and source review.
What is methoxsalen used for in extracorporeal photopheresis?
It makes separated white blood cells sensitive to UVA light. The selected product is licensed to help relieve skin manifestations of advanced cutaneous T-cell lymphoma when other treatment has not worked adequately.
Is methoxsalen injected directly into my body?
No. This formulation is added to a separated white-cell-rich blood fraction outside the body; the treated blood is then returned.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.