Aug 3, 2022

Generic name:  methoxsalen  (oral) [ meth-OX-a-len ]
Brand names: 8-Mop,  Oxsoralen-Ultra
Drug class:  Psoralens

The 8-MOP brand name has been discontinued in the U.S. If generic versions of this product have been approved by the FDA, there may be  generic equivalents available .

What is 8-Mop?

8-Mop works by enhancing the body’s sensitivity to ultraviolet light A (UVA).

8-Mop is used in combination with UVA light therapy to treat severe  psoriasis .

8-Mop can cause harmful effects on your vision and on your skin (premature aging or skin cancer). 8-Mop is used only for severe psoriasis that has not improved with other treatments. You must remain under the care of a doctor while taking this medicine.

8-Mop may also be used for purposes not listed in this medication guide.


You should not use 8-Mop if you are sensitive to light, if you have lens damage in your eye, or if you have had skin cancer.

8-Mop can cause harmful effects on your vision and on your skin. You must avoid natural sunlight for up to 48 hours after UVA treatment.

Oxsoralen-Ultra and 8-Mop are not equivalent medicines and may not have the same dosing schedule.

Before taking this medicine

You should not use 8-Mop if you are allergic to 8-Mop or similar medicines, or if you have:

  • lupus ,  porphyria , albinism, or other conditions that make you more sensitive to light;
  • a history of skin cancer (melanoma or squamous cell carcinoma); 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 8-Mop. 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 8-Mop.

To make sure 8-Mop is safe for you, tell your doctor if you have ever had:

  • heart disease;
  • liver or kidney disease;
  • a  skin pigment disorder ;
  • cataracts;
  • basal cell carcinoma ;
  • extreme sensitivity to sunlight (if you sunburn easily); or
  • radiation or x-ray therapy, or treatment with  arsenic trioxide  (Trisenox).

It is not known whether 8-Mop taken orally will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It may not be safe to breast-feed a baby while you are using this medicine. Ask your doctor about any risks.

How should I take 8-Mop?

You may need to have your eyes examined first.

Follow all directions on your prescription label. Use the medicine exactly as directed.

8-Mop doses are based on weight. Tell your doctor if you gain or lose weight.

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

You may need to keep taking 8-Mop for a short time after UVA treatment. 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 dose needs and UVA light therapy schedule may change. Oxsoralen-Ultra and 8-Mop are not equivalent medicines and may not have the same dosing schedule.

8-Mop will make you more sensitive to sunlight, which can cause harmful effects on your vision and on your skin (premature aging or skin cancer).

For at least 8 hours after you take 8-Mop:

  • 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).
  • Do not expose your skin to any sunlight. 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.
  • 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.

You may develop cataracts if you do not properly protect your eyes after 8-Mop and UVA treatment.

Follow your doctor’s instructions about applying topical psoriasis medications or any moisturizing lotions after your 8-Mop and UVA treatment.

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. You may need to check your skin for signs of cancer throughout the rest of your life.

Store 8-Mop at room temperature away from moisture, heat, and light.

Detailed 8-MOP dosage information

What happens if I miss a dose?

Call your doctor for instructions if you did not take 8-Mop at the correct time before your scheduled UVA treatment. You may need to reschedule.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. You may be instructed to make yourself vomit and stay in a dark room for 24 hours. You will be extremely sensitive to light after an overdose.

What should I avoid while taking 8-Mop?

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

8-Mop side effects

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

8-Mop may cause serious side effects. Call your doctor at once if you have:

  • severe skin redness within 24 hours after UVA treatment;
  • swelling, severe itching, or severe skin discomfort;
  • skin redness and swelling with blisters;
  • worsening of your psoriasis;
  • a new skin lesion, or a mole that has changed in size or color; or
  • blurred vision, tunnel vision,  eye pain  or swelling, or seeing halos around lights.

Mild skin redness may occur and can last for 1 or 2 days. This is a normal side effect after UVA treatment and may not be a sign of severe sunburn. Ask your doctor if you have concerns about any redness or swelling.

Common side effects of 8-Mop may include:

  • itching, redness;
  • nausea ;
  • 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.

8-MOP side effects  (more detail)

What other drugs will affect 8-Mop?

Tell your doctor about all your current medicines and any you start or stop using. 8-Mop can make your skin even more sensitive to sunlight if you also use certain other medicines, especially:

  • anthralin;
  • an  antibiotic  or a sulfa drug;
  • certain antimicrobial soaps;
  • a diuretic or “water pill”;
  • coal tar  applied to the skin or scalp–such as  Neutrogena T/Gel ,  Psoriasin ,  Tegrin Medicated ;
  • medicine to treat mental illness– fluphenazine ,  prochlorperazine ,  thioridazine , and others; or
  • a staining dye–such as  methylene blue , toluidine blue, rose bengal, or methyl orange.

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.


source :: https://www.drugs.com/mtm/8-mop.html