Fluorouracil (5-FU): How to Apply & Side Effects (2024)

Table of Contents

What is this medication? What should I tell my care team before I take this medication? How should I use this medication? What if I miss a dose? What may interact with this medication? What should I watch for while using this medication? What side effects may I notice from receiving this medication? Where should I keep my medication? FAQs References

What is this medication?

FLUOROURACIL, 5-FU (flure oh YOOR a sil) is a chemotherapy agent. It is used on the skin to treat skin cancer and certain types of skin conditions that could become cancer.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Carac, Efudex, Fluoroplex, Tolak

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What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

dihydropyrimidine dehydrogenase (DPD) deficiency
an unusual or allergic reaction to fluorouracil, other chemotherapy, other medicines, foods, dyes, or preservatives
pregnant or trying to get pregnant
breast-feeding

How should I use this medication?

This medicine is only for use on the skin. Follow the directions on the prescription label. Wash hands before and after use. Wash affected area and gently pat dry. To apply this medicine use a cotton-tipped applicator, or use gloves if applying with fingertips. If applied with unprotected fingertips, it is very important to wash your hands well after you apply this medicine. Avoid applying to the eyes, nose, or mouth. Apply enough medicine to cover the affected area. You can cover the area with a light gauze dressing, but do not use tight or air-tight dressings. Finish the full course prescribed by your doctor or health care professional, even if you think your condition is better. Do not stop taking except on the advice of your doctor or health care professional.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, apply it as soon as you can. If it is almost time for your next dose, only use that dose. Do not apply extra doses. Contact your doctor or health care professional if you miss more than one dose.

What may interact with this medication?

Interactions are not expected. Do not use any other skin products without telling your doctor or health care professional.

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Visit your doctor or health care professional for checks on your progress. You will need to use this medicine for 2 to 6 weeks. This may be longer depending on the condition being treated. You may not see full healing for another 1 to 2 months after you stop using the medicine.

Treated areas of skin can look unsightly during and for several weeks after treatment with this medicine.

Do not get this medicine in your eyes. If you do, rinse out with plenty of cool tap water.

This medicine can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps or tanning beds/booths.

Serious side effects or death can occur if a pet comes into contact with this drug. Contact a vet right away if a pet touches or licks the drug on your skin or comes into contact with the container. Throw away or wash any items used to apply this drug. Wash your hands after applying the drug. Make sure the drug does not get on clothing, carpet, or furniture. If you cannot avoid skin to skin contact with your pet, ask your health care provider if you can cover the area(s) where you apply this drug.

Do not become pregnant while taking this medicine or for 1 month after stopping it. Women should inform their doctor if they wish to become pregnant or think they might be pregnant. There is a potential for serious side effects to an unborn child. Talk to your health care professional or pharmacist for more information.

What side effects may I notice from receiving this medication?

Side effects that you should report to your doctor or health care professional as soon as possible:

allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
bloody diarrhea
fever or chills
stomach pain
vomiting

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

redness or dry skin
sensitivity to light

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

See product for storage instructions. Each product may have different instructions. Throw away any unused medicine after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

FAQs

Fluorouracil (5-FU): How to Apply & Side Effects? ›

Before you apply this medication to the skin, clean the affected area and dry well. Wait 10 minutes, then apply a small amount of medication to the affected skin, using just enough to cover the area with a thin film. Wash your hands immediately after applying this medication, even if you have used gloves.

What is the proper way to apply fluorouracil cream? ›

Wash the affected area and dry completely before applying fluorouracil cream. Apply fluorouracil cream in a thin layer over the entire affected area. It can be applied using a nonmetal applicator, a glove or your fingertips.

Keep Reading ›

How do you know when you have used fluorouracil cream long enough? ›

If you are using fluorouracil to treat actinic or solar keratoses, you should continue using it until the lesions start to peel off. This usually takes about 2 to 4 weeks. However, the lesions may not be completely healed until 1 or 2 months after you stop using fluorouracil.

How can I speed up healing after fluorouracil treatment? ›

After you have been instructed to stop using the fluorouracil cream, you may be prescribed a specific moisturiser or mild topical steroid< to help to heal the treated area. If you have been given no specific instructions, apply plain white petrolatum thinly to raw and crusted areas at bedtime.

Learn More Now ›

Is one week long enough to use fluorouracil? ›

One-week treatment with once-daily fluo- rouracil cream 0.5% is an effective well-tolerated therapy for AKs. Using this short treatment dura- tion period in combination with cryosurgery may prove beneficial in clinical practice. Extending treatment for up to 4 weeks will further improve AK lesion clearance rates.

Show Me More ›

Can you use too much fluorouracil cream? ›

It is very important that you use this medicine only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. To do so may cause your skin to become irritated.

Learn More ›

How do I know when to stop applying fluorouracil? ›

If you are using fluorouracil to treat actinic or solar keratoses, you should continue using it until the lesions start to scab, weep, or form open sores. This usually takes about 2-4 weeks.

Show Me More ›

What to avoid when using fluorouracil? ›

Avoid exposure to sunlight or tanning beds. Fluorouracil topical can make you sunburn more easily. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.