Trioxasalen is used in the treatment of vitiligo and psoriasis.

Trioxasalen is used along with ultraviolet-A irradiation where it works by decreasing the number of cells the skin makes.

Redness of skin, Blisters on skin, Edema, Itching

• Trioxsalen is a very strong medicine that increases your skin sensitivity to sunlight. Do not use it for sun tanning or to increase tolerance to sunlight; if doing so, do not use trioxsalen for more than 14 days.
• Take this treatment (trioxsalen and UVA) two or three times a week with the treatment spaced at least forty-eight hours apart.  
• Take this medication by mouth with food or milk, usually 2 to 4 hours before your UVA light treatment.
• Do not sunbathe for 24 hours before taking trioxsalen.  Wear UVA-absorbing, wrap-around sunglasses and cover exposed skin or use a sunblock (SP 15 or higher) for the twenty-four (24) hour period following treatment with trioxsalen.
• Use extra caution for at least 48 hours following each treatment.  After each treatment, cover your skin for at least 8 hours by wearing protective clothing.
• Do not increase the amount of trioxsalen if you are taking or spend extra time in the sunlight or under an ultraviolet lamp.
• Do not drive or operate machinery as trioxsalen may cause dizziness.
• You will need to have an eye examination before starting trioxsalen and also once a year thereafter.
• Be careful before applying anything to your skin to treat dryness and itchiness caused by trioxsalen.
• Tell your doctor if you are or planning to become pregnant or are breastfeeding.