Pronunciation: meth OX a len

Brand: 8-Mop, Oxsoralen-Ultra

What is the most important information I should know about methoxsalen?

You should not use methoxsalen if you have a condition that makes you more sensitive to light (lupus, porphyria, albinism, and others), or if you have a history of skin cancer or damage to the lenses of your eyes due to surgery, injury, or genetic condition.

Methoxsalen can cause harmful effects on your vision and on your skin (premature aging or skin cancer). This medicine is used only for severe psoriasis that has not improved with other treatments. You must remain under the care of a doctor while taking methoxsalen.

If your doctor changes your brand, strength, or type of methoxsalen, your dosage needs and UVA light therapy schedule may change. Oxsoralen-Ultra and 8-Mop are not equivalent medicines and may not have the same dose or schedule. Ask your pharmacist if you have any questions about the new kind of methoxsalen you receive at the pharmacy.

What is methoxsalen?

Methoxsalen is a naturally occurring substance that is reactive to light. It works by enhancing the body's sensitivity to ultraviolet light A (UVA).

Methoxsalen is used in combination with UVA light therapy to treat severe psoriasis. Methoxsalen is usually given after other psoriasis medicines have been tried without success.

Methoxsalen can cause harmful effects on your vision and on your skin (premature aging or skin cancer). This medicine is used only for severe psoriasis that has not improved with other treatments. You must remain under the care of a doctor while taking methoxsalen.

Methoxsalen may also be used for purposes not listed in this medication guide.

What should I discuss with my health care provider before taking methoxsalen?

You should not use this medicine if you are allergic to methoxsalen or similar "psoralen" medicines, or if you have:

  • a history of skin cancer;
  • lupus, porphyria, albinism, or other conditions that make you more sensitive to light; or
  • damage to the lenses of your eyes caused by surgery, injury, or genetic condition.

Before your UVA treatment: Do not expose your skin to sunlight for at least 24 hours before you take methoxsalen. Avoid applying sunscreen to areas of psoriasis that will be treated with UVA therapy.

You may need to have your eyes examined before you start taking methoxsalen.

To make sure methoxsalen is safe for you, tell your doctor if you have:

  • heart disease;
  • liver disease;
  • a skin pigment disorder;
  • a history of cataracts;
  • a history of basal cell carcinoma;
  • if you are extremely sensitive to sunlight;
  • if you have ever received radiation or x-ray therapy, or used arsenic trioxide (Trisenox); or
  • if you have recently gained or lost weight.

FDA pregnancy category C. It is not known whether methoxsalen will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

It is not known whether methoxsalen passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

How should I take methoxsalen?

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

You will take methoxsalen a certain number of hours before you are scheduled to receive UVA treatment. The soft gelatin capsule (Oxsoralen-Ultra) is more easily absorbed in the body than the hard gelatin capsule (8-Mop). The timing of your dose will depend on which type of capsule you are taking.

You may also need to keep taking methoxsalen after your UVA treatment, either for a short time or as needed. Follow your doctor's dosing instructions very carefully.

Take this medicine with low-fat food or milk if it upsets your stomach.

If your doctor changes your brand, strength, or type of methoxsalen, your dosage needs and UVA light therapy schedule may change. Oxsoralen-Ultra and 8-Mop are not equivalent medicines and may not have the same dose or schedule. Ask your pharmacist if you have any questions about the new kind of methoxsalen you receive at the pharmacy.

Methoxsalen will make your skin more sensitive to sunlight and sunburn may result, which could interfere with your psoriasis treatment.

For at least 8 hours after you take methoxsalen:

  • Avoid exposure to sunlight or tanning beds.
  • Even sunlight shining through clouds or through a glass window can expose you to harmful UV rays.
  • Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors or near a window.
  • Do not apply sunscreen to areas of active psoriasis that will be treated with UVA therapy.

For 24 to 48 hours after you receive UVA treatment:

  • You must protect your skin and eyes from natural sunlight (even sun shining through a window).
  • Wear sunglasses for at least 24 hours after treatment.
  • For utmost protection, wear a pair of wraparound UVA-absorbing sunglasses, even while you are indoors near a window.
  • Do not expose your skin to sunlight or tanning beds for at least 48 hours. Wear protective clothing including a hat and gloves. Use a sunscreen with a minimum SPF of 30, and apply it to all uncovered skin areas exposed to light.

You may develop cataracts if you do not properly protect your eyes after you are treated with methoxsalen and UVA treatment.

Follow your doctor's instructions about applying topical psoriasis medications or any moisturizing lotions after your methoxsalen and UVA treatment.

While taking methoxsalen, check your skin regularly for signs of skin cancer, such as a small growth or nodule, a scaly or crusted lesion, a brownish spot or speckles, or a change in the size, color, or feel of a mole. After receiving UVA treatments, you may need to check your skin for signs of cancer throughout the rest of your life.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Call your doctor for instructions if you miss your dose or forget to take the medicine within the proper amount of time before your scheduled UVA treatment. You may need to reschedule your light therapy appointment if you have not taken methoxsalen at the correct time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. You will be extremely sensitive to light after an overdose.

What should I avoid while taking methoxsalen?

Avoid exposure to sunlight or artificial UV rays other than your scheduled light therapy treatments.

What are the possible side effects of methoxsalen?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • severe skin redness within 24 hours after UVA treatment;
  • severe itching, swelling, or severe skin discomfort;
  • blisters, pimples, or skin rash;
  • blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • feeling like you might pass out; or
  • worsening of your psoriasis.

Mild skin redness may occur several hours after your UVA treatment and can last for 2 or 3 days. This is a normal effect of methoxsalen and UVA treatment, and may not be a sign of severe sunburn. Ask your doctor if you have concerns about any redness or swelling of your skin.

Common side effects may include:

  • itching;
  • nausea;
  • depression, feeling nervous; or
  • sleep problems (insomnia).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect methoxsalen?

Tell your doctor about all medicines you use, and those you start or stop using during your treatment with methoxsalen. Methoxsalen can make your skin even more sensitive to sunlight if you also use certain other medicines, especially:

  • griseofulvin;
  • nalidixic acid;
  • an antibiotic (such as ciprofloxacin (Cipro), doxycycline, levofloxacin (Levaquin), minocycline, ofloxacin, tetracycline), and others;
  • a bacteriostatic soap;
  • coal tar applied to the skin or scalp (Neutrogena T/Gel, Psoriasin, Tegrin Medicated, and others);
  • a diuretic or "water pill";
  • medicine to treat mental illness (such as chlorpromazine, fluphenazine, prochlorperazine, thioridazine, and others);
  • a staining dye such as methylene blue, toluene blue, rose bengal, or methyl orange; or
  • a sulfa drug (Bactrim, SMX-TMP or SMZ-TMP, and others).

This list is not complete. Other drugs may interact with methoxsalen, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Where can I get more information?

Your doctor or pharmacist can provide more information about methoxsalen.


Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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