What is methoxsalen? What is methoxsalen used for?
- Methoxsalen is a naturally occurring photoactive chemical found in the seeds
of the Ammi majus (Umbelliferae) plant and in the roots of Heraclem candicans.
It belongs to a group of compounds known as psoralens, or furocoumarins.
Methoxsalen lotion is used for treating vitiligo (leucoderma). The exact
mechanism of action of methoxsalen is not known. - Methoxsalen has several biological actions that may be responsible for its medical effects. Methoxsalen is a photosensitizer that increases the reaction of skin cells to UVA. Some experts suggest that methoxsalen improves vitiligo by stimulating melanocytes (melanin forming skin cells) to move up the hair follicle and to repopulate the epidermis. Methoxsalen also combines with DNA in skin cells, leading to inhibition of DNA synthesis, cell division, and reduced formation of new skin cells. Administration of methoxsalen combined with UVA exposure causes cellular damage, leading to skin inflammation and erythema. The damaged skin heals after several days to weeks.
- The FDA approved methoxsalen lotion in December 1954.
What brand names are available for methoxsalen?
Oxsoralen
Is methoxsalen available as a generic drug?
No
Do I need a prescription for methoxsalen?
Yes
What are the uses for methoxsalen?
- Methoxsalen lotion is a topical repigmenting agent for treating
vitiligo (leucoderma). It is used in conjunction with controlled doses of
ultraviolet A light (UVA, 320-400 nm) or sunlight.
What are the side effects of methoxsalen?
Common side effects include:
- Severe burns from over exposure to UVA or sunlight
- Blisters
- Sun sensitivity (photosensitivity)
What is the dosage for methoxsalen?
- Methoxsalen lotion should be applied to the affected area 2 hr. before UV
exposure every 3 to 7 days. - It takes a few weeks for pigmentation to begin.
- Significant repigmentation may take 6 to 9 months of treatment and re-treatment
may be necessary to retain the new pigment.
Which drugs or supplements interact with methoxsalen?
- Use of drugs that cause sun sensitivity will increase the risk of severe skin
burns when using methoxsalen lotion. Examples of such drugs include doxycycline
(Vibramycin), tetracycline, demeclocycline, methylene blue (Provayblue), and several other drugs.
Is methoxsalen safe to take if I’m pregnant or breastfeeding?
- Methoxsalen lotion has not been studied in pregnant women and it is not known
whether methoxsalen can harm the fetus when used by a pregnant woman. It is not
known whether methoxsalen is absorbed into the blood stream when it is applied
to the skin. Methoxsalen lotion should be used in pregnant women only when
clearly needed. - It is not known whether methoxsalen is excreted in
human milk
after it is applied to the skin.
What else should I know about methoxsalen?
What preparations of methoxsalen are available?
Lotion: 1%
How should I keep methoxsalen stored?
Methoxsalen lotion should be stored at 15 to 30 C (59 to 86 F)