Methoxsalen is used in combination with a specific kind of light therapy (controlled exposure to long wavelength ultraviolet radiation) to treat certain types of skin problems such as vitiligo (loss of skin colour in patches), and psoriasis (a type of skin disease that is caused by itchy patches of thick, red skin and silvery scales).
Take Methoxsalen exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
Take with meals or with a glass of milk before the light radiation therapy. Try to take it at the same time each day.
The dose of this medicine will be decided by your doctor. Your doctor will advise you on the course of the treatment depending on your condition and response to the medication.
Methoxsalen must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed to do so by the doctor.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Alert your doctor if you have the following conditions:
- current or history of skin cancer
- systemic lupus erythematosus (autoimmune disease that causes inflammation)
- albinism (lack of pigment in the skin, hair or eyes)
- an inherited disorder that may cause skin or nerve problems
- absence of lens in the eyes
as Methoxsalen may not be suitable for you.
Inform your doctor if you have the following conditions:
- liver disease
- heart disease
- previous x-ray therapy
- previous arsenic therapy
Let your doctor know if you are pregnant or breastfeeding.
Wear protective clothing and sunglass when going outdoors. Avoid direct or prolonged exposure to the sun and ultraviolet (UV) lamps like tanning beds.
Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly. Routine tests (e.g. complete blood count, liver and kidney function test, eye exam) while you are being treated with this medicine. Your doctor will advise you on how often you need to have these tests.
Methoxsalen may cause any of the following side effects: nausea, headache, dizziness, difficulty sleeping, nervousness, depression, skin irritation, itching, redness, tenderness, or blistering.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- severe skin irritation, sunburn
- skin growth
- problems with your eyesight such as vision changes
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Inform your doctor or pharmacist if you are taking any of these medicines:
- certain antibiotics e.g. sulfonamides, tetracyclines, fluoroquinolones
- medicines for high blood pressure or heart disease e.g. thiazide
- other medicines for psoriasis e.g. anthralin, coal tar or its derivatives
This list does not include all medicines that may interact with Methoxsalen.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Avoid furocoumarin containing foods e.g. limes, figs, parsley, celery, cloves, lemon, mustard, carrots.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.