Methoxsalen (By mouth)
Treats the symptoms of psoriasis. Used before treatment with ultraviolet radiation (UV light) so your skin will respond better to the treatment.
When This Medicine Should Not Be Used
How to Use This Medicine
- Your doctor will tell you how much medicine to use. Do not use more than directed.
- Use only the brand of medicine your doctor prescribed. Other brands may not work the same way.
- Take this medicine about 1½ to 2 hours before you have your UV treatment.
- It is best to take this medicine with milk, or low-fat foods such as fresh fruit, crackers, toast or bagels. If this medicine upsets your stomach, ask your doctor or pharmacist if you can take your dose at two different times. You may be able to take half of the dose, and then take the other half about 30 minutes later.
If a dose is missed:
- If you do not take your medicine at the correct time, take it as soon as possible. Tell your health caregiver what time you took your medicine.
- Do not use extra medicine to make up for a missed dose.
How to Store and Dispose of This Medicine
- Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
- Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
- Keep all medicine out of the reach of children. Never share your medicine with anyone.
Drugs and Foods to Avoid
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
- Tell your doctor if you are using any other medicine that might also make your skin more sensitive to light. These medicines include anthralin (Psoriatec®), coal tar, griseofulvin (Grifulvin®, Gris-Peg®), nalidixic acid (NegGram®), and halogenated salicylanilides (bacteriostatic soaps). They also include thiazide diuretics ("water pills"), such as hydrochlorothiazide (HCTZ), or some staining dyes such as methylene blue, toluidine blue, rose bengal, or methyl orange.
- Make sure your doctor knows if you are using a sulfonamide medicine, such as trimethoprim/sulfamethoxazole, Bactrim®, Cotrim®, or Septra®, or if you are using a tetracycline medicine, such as doxycycline (Vibramycin®), or minocycline (Minocin®). Tell your doctor if you are using a phenothiazine medicine, such as prochlorperazine, Compazine®, Mellaril®, Phenergan®, or Thorazine®.
- Make sure your doctor knows if you have ever had radiation therapy or arsenic therapy.
Warnings While Using This Medicine
- Make sure your doctor knows if you are pregnant or breast feeding, or if you have basal cell carcinoma (a type of skin cancer). Make sure your doctor knows if you have liver disease or any heart problems.
- You could get a serious sunburn while using this medicine. Carefully follow all instructions from your doctor. The UV light treatment may also tan your skin or cause freckles.
- Do not sunbathe ("lay out") or tan in the 24 hours (1 day) before taking this medicine. Do not sunbathe for 48 hours (2 days) after your UV light treatment.
- Stay out of sunlight for at least 8 hours after you have taken this medicine. This includes avoiding sunlight that comes in from a window or when riding in a car. Also be aware that even when the sky is cloudy, the UV light can reach your skin. If you must be in the sun, wear clothing that covers all of your skin. This includes long sleeves, a hat, and gloves. You can also apply sunscreen that has an SPF (sun protection factor) of greater than 15. However, do not put the sunscreen on any areas of your skin where you have psoriasis until after you have had your UV light treatment.
- Wear wrap-around sunglasses that will protect your eyes from UV light for at least 24 hours (1 day) after taking this medicine. Show your sunglasses to health caregivers. Caregivers will make sure that your sunglasses protect your eyes from UV light.
- Your skin might turn red after your treatment. If your skin turns very red, or starts to blister or peel, call your doctor.
- If your skin itches because of this treatment, ask your health caregiver what kind of cream or lotion you can use to stop the itching. If the itching does not stop, call your doctor.
- Call your doctor if your symptoms do not improve or if they get worse.
- You should have your eyes checked before you start to use this medicine. Schedule eye check-ups every year after you stop using this medicine.
Possible Side Effects While Using This Medicine
Call your doctor right away if you notice any of these side effects:
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Trouble seeing or any vision changes.
If you notice these less serious side effects, talk with your doctor:
- Trouble sleeping.
- Unusual sadness or nervousness.
If you notice other side effects that you think are caused by this medicine, tell your doctor
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088
- Last reviewed on 1/27/2017
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