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Methoxsalen Topical Dosage

Applies to the following strengths: 1%

Usual Adult Dose for:

Additional dosage information:

Usual Adult Dose for Vitiligo

Methoxsalen lotion should be applied to a well-defined area of vitiligo by the physician, followed by exposure of the area to controlled doses of ultraviolet A (320 to 400 nm) or sunlight. Initial exposure time should be conservative and not exceed that which is predicted to be one-half the minimal erythema dose.

Treatment intervals should be regulated by the erythema response. Usually, once a week or less often is recommended depending upon results.

Treatment should be individualized, as repigmentation will vary in completeness, time of onset, and duration. Pigmentation may begin after a few weeks but significant repigmentation may require 6 to 9 months of treatment.

Periodic retreatment may be necessary to retain all of the new pigment.

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

Data not available


Methoxsalen is a potent drug capable of causing severe burns if used improperly. Methoxsalen lotion should be applied only by a physician under controlled conditions for light exposure and subsequent light shielding. It should never be dispensed to the patient.

Methoxsalen lotion should be applied only on small, well-defined lesions. The treated area may be highly photosensitive for several days, resulting in severe burn injury if exposed to additional UVA or sunlight. Patients should be instructed to protect all treated areas with protective covering and/or sunscreen after therapeutic UVA exposure.

The hands and fingers of the person applying methoxsalen lotion should be protected by gloves or finger cots to avoid photosensitization and possible burns.

Safety and effectiveness have not been established in pediatric patients less than 12 years of age. Use of methoxsalen lotion in this population is considered contraindicated by the manufacturer.


Data not available

Other Comments

Treatment must be individualized. Repigmentation will vary in completeness as well as time of onset and duration, occurring more rapidly in fleshy areas such as the face, abdomen, and buttocks and less rapidly in less fleshy areas such as the dorsum of the hands and feet.

The length of time the skin remains sensitized or when the maximum erythema will occur is quite variable from person to person.

Minor blistering in the treated areas of the skin is not a contraindication to further treatment and generally heals without incident.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.