8-MOP Dosage

Generic name: Methoxsalen 10mg
Dosage form: capsule, gelatin coated
Drug class: Psoralens

Medically reviewed by Drugs.com. Last updated on Jan 20, 2025.

A. VITILIGO THERAPY

DRUG DOSAGE

Two capsules (10 mg each) in one dose taken with milk or in food two to four hours before ultraviolet light exposure.

LIGHT EXPOSURE

The exposure time to sunlight should comply with the following guide:

	Basic Skin Color
	Light	Medium	Dark
Initial Exposure	15 min.	20 min.	25 min.
Second Exposure	20 min.	25 min.	30 min.
Third Exposure	25 min.	30 min.	35 min.
Fourth Exposure	30 min.	35 min.	40 min.

Subsequent Exposure

Gradually increase exposure based on erythema and tenderness of the amelanotic skin.

Therapy should be on alternate days and never two consecutive days.

B. PSORIASIS THERAPY

DRUG DOSAGE - INITIAL THERAPY

The methoxsalen capsules should be taken 2 hours before UVA exposure with some food or milk according to the following table:

Patient's Weight		Dose
(kg)	(lbs)	(mg)
<30	<66	10
30-50	66-110	20
51-65	112-143	30
66-80	146-176	40
81-90	179-198	50
91-115	201-254	60
>115	>254	70

Additional drug dosage directions are as follows:

a. Weight Change: In the event that the weight of a patient changes during treatment such that he/she falls into an adjacent weight range/dose category, no change in the dose of methoxsalen is usually required. If, in the physician's opinion, however, a weight change is sufficiently great to modify the drug dose, then an adjustment in the time of exposure to UVA should be made.

b. Dose/Week: The number of doses per week of methoxsalen capsules will be determined by the patient's schedule of UVA exposures. In no case should treatments be given more often than once every other day because the full extent of phototoxic reactions may not be evident until 48 hours after each exposure.

c. Dosage Increase: Dosage may be increased by 10 mg. after the fifteenth treatment under the conditions outlined in section XI.B.4.b.