Methoxsalen (Topical)

Methoxsalen is part of a group of medicines known as psoralens. It is used together with ultraviolet light (which comes from sunlight and certain special lamps) in a treatment called psoralen plus ultraviolet light A (PUVA) to treat vitiligo, a condition where skin color is lost. Methoxsalen may also be used for other conditions as decided by your doctor.

Methoxsalen is available only with a prescription and must be given by or under the direct supervision of your doctor.

It is important that you visit your doctor as directed for treatments and to have your progress checked.

This medicine increases how sensitive the treated areas of your skin are to sunlight. Therefore, being in the sun, even through window glass or on a cloudy day, could lead to a serious burn. After each light treatment, wash the treated areas of your skin thoroughly. Also, if you need to go out during daylight hours, cover the treated areas of your skin for at least 12 to 48 hours following treatment by wearing protective clothing or a sun block product with a skin protection factor (SPF) of at least 15. Some patients may need a product with a higher SPF number, especially if they have a fair complexion. If you have any questions about this, check with your health care professional.

The treated areas of your skin may remain sensitive to sunlight for some time after treatment with this medicine. Use extra caution for at least 72 hours following each treatment if you plan to spend any time in the sun. In addition, do not sunbathe at any time during your course of treatment with methoxsalen.

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 issue.

In deciding to use a medicine, you need to consider the risks of taking it against the benefits it will bring. This is a choice you will make with your doctor. For this medicine, keep the following in mind:

Methoxsalen is a very strong medicine that makes your skin more sensitive to sunlight. If not used correctly, it can lead to serious sunburns and may increase the risk of skin cancer. Like excessive sunlight, PUVA can also cause your skin to age prematurely. Therefore, methoxsalen should only be used as directed and should not be used just for tanning. Make sure you discuss its use with your doctor before starting this medicine.

Allergies

Tell your doctor if you have ever had any unusual or allergic reactions to this medicine or any other medicines. Also inform your healthcare professional if you have any other allergies, such as to foods, dyes, preservatives, or animals. For over-the-counter products, read the label or package ingredients carefully.

Pediatric

Studies on this medicine have only been conducted in adult patients, and there is no specific information comparing the use of methoxsalen in children up to 12 years of age with its use in other age groups.

Geriatric

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

Breast Feeding

There are no adequate studies in women to determine the risk to infants when using this medication during breastfeeding. Consider the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

While some medicines should never be used together, in other cases, two different medicines may be used together even if an interaction could occur. In these situations, your doctor may need to adjust the dose or take other precautions. When taking this medicine, it's especially important for your healthcare professional to know if you are taking any of the medicines listed below. The following interactions are highlighted for their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be necessary in some cases. If both medicines are prescribed together, your doctor may adjust the dose or the frequency of use for one or both medicines.

• Anagrelide
• Tegafur

Using this medicine with any of the following medicines may increase the risk of certain side effects, but using both drugs might be the best treatment for you. If both medicines are prescribed together, your doctor may adjust the dose or how often you use one or both medicines.

• Fosphenytoin
• Phenytoin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be taken at or around meal times, or with certain types of food, because interactions may happen. Using alcohol or tobacco with certain medicines may also cause interactions. Talk with your healthcare professional about how to use your medicine with food, alcohol, or tobacco.

Other Medical Problems

Having other medical problems may affect how you can use this medicine. Be sure to tell your doctor if you have any other medical issues, especially:

• Allergy to sunlight (or a family history of it) or
• Infection or
• Lupus erythematosus or
• Porphyria or
• Skin cancer (history of) or
• Other skin conditions—Using PUVA may worsen these conditions

• Severe heart or blood vessel disease—The heat or prolonged standing during each light treatment may worsen this condition.

Along with its necessary effects, a medicine may cause some unwanted effects. Not all of these side effects may happen, but if they do, they may require medical attention.

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

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

There is an increased risk of developing skin cancer after using methoxsalen. You should regularly check the treated areas of your body and show your doctor any skin sores that do not heal, new skin growths, and skin growths that have changed in appearance or feel.

Premature aging of the skin may happen due to long-term methoxsalen therapy. This effect is permanent and is similar to the results of sunbathing for extended periods.

Other side effects that are not listed may also happen 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.

In the U.S.

• Oxsoralen

In Canada

• Ultramop

Chemical Class: Psoralen

Eating certain foods while you are using methoxsalen 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.

Use this medicine only under the direct supervision of your doctor.

After UVA exposure, wash the treated area of skin with soap and water. Then use a sunscreen or wear protective clothing to protect the area.

Dosing

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 topical solution dosage form: For vitiligo: Adults and children 12 years of age and over—Apply to the affected area of the skin and allow to dry for one to two minutes, then apply again within two to two and one-half hours before UVA exposure. Children under 12 years of age—Use and dose must be determined by your doctor.