Methoxsalen (5 brand names, 3 dosage forms, 3 routes)
Available dosage forms: INJECTABLE, LOTION, CAPSULE.
Routes of administration: INJECTION, TOPICAL, ORAL.
Brand Names
- 8-MOP
- METHOXSALEN
- OXSORALEN
- OXSORALEN-ULTRA
- UVADEX
Boxed Warning
Methoxsalen with ultraviolet (UV) radiation should be used only by physicians who have special competence in the diagnosis and treatment of psoriasis and who have special training and experience in photochemotherapy. The use of Psoralen and ultraviolet radiation therapy should be under constant supervision of such a physician. For the treatment of patients with psoriasis, photochemotherapy should be restricted to patients with severe, recalcitrant, disabling psoriasis which is not adequately responsive to other forms of therapy, and only when the diagnosis is certain. Because of the possibilities of ocular damage, aging of the skin, and skin cancer (including melanoma), the patient should be fully informed by the physician of the risks inherent in this therapy.
Indications and Usage
Photochemotherapy (Methoxsalen with long wave UVA radiation) is indicated for the symptomatic control of severe, recalcitrant, disabling psoriasis not adequately responsive to other forms of therapy and when the diagnosis has been supported by biopsy. Methoxsalen is intended to be administered only in conjunction with a schedule of controlled doses of long wave ultraviolet radiation.
Dosage and Administration
CAUTION: Methoxsalen Capsules, USP represents a new dose form of methoxsalen. This new dosage form of methoxsalen exhibits significantly greater bioavailability and earlier photosensitization onset time than previous methoxsalen dosage forms. Each patient should be evaluated by determining the minimum phototoxic dose (MPD) and phototoxic peak time after drug administration prior to onset of photochemotherapy with this dosage form. Human bioavailability studies have indicated the following drug dosage and administration directions are to be used as a guideline only.
Contraindications
A. Patients exhibiting idiosyncratic reactions to psoralen compounds. B. Patients possessing a specific history of light sensitive disease states should not initiate methoxsalen therapy except under special circumstances. Diseases associated with photosensitivity include lupus erythematosus, porphyria cutanea tarda, erythropoietic protoporphyria, variegate porphyria, xeroderma pigmentosum, and albinism. C. Patients with melanoma or with a history of melanoma. D. Patients with invasive squamous cell carcinomas. E. Patients with aphakia, because of the significantly increased risk of retinal damage due to the absence of lenses.
Drug Interactions
See WARNINGS – GENERAL.
Overdosage
In the event of methoxsalen overdosage, induce emesis and keep the patient in a darkened room for at least 24 hours. Emesis is most beneficial within the first 2 to 3 hours after ingestion of methoxsalen, since maximum blood levels are reached by this time.