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Trioxsalen (Oral)

Generic name: trioxsalen [ trye-OX-sa-len ]
Drug class: Psoralens

Medically reviewed by Last updated on Aug 30, 2022.

Uses for trioxsalen

Trioxsalen belongs to the group of medicines called psoralens. It is used along with ultraviolet light (found in sunlight and some special lamps) in a treatment called psoralen plus ultraviolet light A (PUVA) to treat vitiligo, a disease in which skin color is lost. Trioxsalen may also be used for other conditions as determined by your doctor.

Trioxsalen was available only with your doctor's prescription.

Trioxsalen was discontinued by the manufacturer in December 2002.

Before using trioxsalen

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Trioxsalen is a very strong medicine that increases the skin's sensitivity to sunlight. In addition to causing serious sunburns if not properly used, it has been reported to increase the chance of skin cancer and cataracts. Also, like too much sunlight, PUVA can cause premature aging of the skin. Therefore, trioxsalen should be used only as directed and it should not be used simply for suntanning. Before using this medicine, be sure that you have discussed its use with your doctor.


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Although there is no specific information comparing use of trioxsalen in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults.


Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of trioxsalen in the elderly with use in other age groups.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Allergy to sunlight (family history of) or
  • Lupus erythematosus or
  • Porphyria or
  • Other conditions that make you more sensitive to light—This medicine will make the condition worse.
  • Eye problems, such as cataracts or loss of the lens of the eyes—Use of this medicine may make your cataracts or other eye problems worse; having no lens in your eye may increase the side effects of this medicine.
  • Heart or blood vessel disease (severe)—The heat from the light treatment may make the condition worse.
  • Infection or
  • Stomach problems—Use of this medicine may make the condition worse.
  • Melanoma or other skin cancer (history of) or
  • Recent treatment with x-rays or cancer medicines or plans to have x-rays in the near future—May increase your chance of skin cancer.

Proper use of trioxsalen

This medicine may take several weeks or months to help your condition. Do not increase the amount of trioxsalen you are taking or spend extra time in the sunlight or under an ultraviolet lamp. This will not make the medicine act any more quickly and may result in a serious burn.

If this medicine upsets your stomach, it may be taken with meals or milk.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For vitiligo:
      • Adults and children 12 years of age and over—20 to 40 milligrams (mg) taken two to four hours before ultraviolet light A (UVA) exposure. This treatment (trioxsalen and UVA) is given two or three times a week with the treatments spaced at least forty-eight hours apart.
      • Children up to 12 years of age—Dose must be determined by your doctor.
    • For increasing tolerance to sunlight or increasing color of the skin:
      • Adults and children 12 years of age and over—20 to 40 mg taken two hours before ultraviolet light A (UVA) exposure. This treatment (trioxsalen and UVA) is given two or three times a week with the treatments spaced at least forty-eight hours apart.
      • Children up to 12 years of age—Dose must be determined by your doctor.

Missed Dose

Call your doctor or pharmacist for instructions.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Precautions while using trioxsalen

Your doctor should check your progress at regular visits to make sure this medicine is working and that it does not cause unwanted effects. Eye examinations should be included.

This medicine increases the sensitivity of your skin and lips to sunlight. Therefore, exposure to the sun, even through window glass or on a cloudy day, could cause a serious burn. If you must go out during the daylight hours:

  • Before each treatment, cover your skin for at least 24 hours by wearing protective clothing, such as long-sleeved shirts, full-length slacks, wide-brimmed hat, and gloves. In addition, protect your lips with a special sun block lipstick that has a skin protection factor of at least 15. Check with your doctor before using sun block products on other parts of your body before a treatment, since sun block products should not be used on the areas of your skin that are to be treated.
  • After each treatment, cover your skin for at least 8 hours by wearing protective clothing. In addition, use a sun block product that has a skin protection factor of at least 15 on your lips and on those areas of your body that cannot be covered.

If you have any questions about this, check with your health care professional.

Your skin may continue to be sensitive to sunlight for some time after treatment with this medicine. Use extra caution for at least 48 hours following each treatment if you plan to spend any time in the sun. Do not sunbathe during this time.

For 24 hours after you take each dose of trioxsalen, your eyes should be protected during daylight hours with special wraparound sunglasses that totally block or absorb ultraviolet light (ordinary sunglasses are not adequate). This is to prevent cataracts. Your doctor will tell you what kind of sunglasses to use. These glasses should be worn even in indirect light, such as light coming through window glass or on a cloudy day.

Eating certain foods while you are taking trioxsalen may increase your skin's sensitivity to sunlight. To help prevent this, avoid eating limes, figs, parsley, parsnips, mustard, carrots, and celery while you are being treated with this medicine.

This medicine may cause your skin to become dry or itchy. However, check with your doctor before applying anything to your skin to treat this problem.

Side Effects of trioxsalen

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

  • Blistering and peeling of skin
  • reddened, sore skin
  • swelling, especially of feet or lower legs

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Itching of skin
  • nausea

Less common

  • Dizziness
  • headache
  • mental depression
  • nervousness
  • trouble in sleeping

There is an increased risk of developing skin cancer after use of trioxsalen. You should check your body regularly and show your doctor any skin sores that do not heal, new skin growths, and skin growths that have changed in the way they look or feel.

Premature aging of the skin may occur as a result of prolonged trioxsalen therapy. This effect is permanent and is similar to what happens when a person sunbathes for long periods of time.

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.