What Is It?
Fluorouracil cream is also known as “mean cream,” Efudex®, “chemo cream,” or 5-FU.
Topical fluorouracil (5-FU) is a medication commonly prescribed to treat actinic keratoses, which are precancerous lesions on the skin caused by sun exposure. The drug works by targeting only the precancerous cells that are trying to multiply faster than normal cells. Fluorouracil locks up the dividing process. Once the cell’s machinery is locked, it undergoes programmed cell death, and then your immune system comes by to clean up the locked cells. If you put it on skin that doesn’t have a lot of damage, it doesn’t do much, because those cells aren’t turning over as rapidly.
Fluorouracil comes in multiple strengths. They are all effective, so we try to pick the one we think your insurance is likely to cover. However, insurance rules change every 90 days, and sometimes what was covered gets deleted from formularies, or it is covered BUT the copay is unethically high. FOR THIS REASON, WE ASK THAT YOU NOT PAY MORE THAN $50 FOR THIS MEDICINE. PLEASE CALL US BACK AND WE WILL USE A COMPOUNDED OPTION THAT GETS SHIPPED (for free) TO YOUR HOME.
How Do I Use It?
Treatment with topical 5-FU usually consists of applying the medication once daily for one to four weeks. We usually recommend 1 week for the lip, 2 weeks for the face, and up to 4 weeks on the arms and hands. We may tell you to just put it on specific areas, or, if you have more precancers, we may suggest using it over broader areas of skin.
What Should I Expect?
EXPECT THINGS TO LOOK WORSE BEFORE THEY GET BETTER! Common side effects of topical 5-FU include redness, burning, stinging, and irritation at the application site. If these expected side effects get to be so bothersome that you can’t sleep, or if anything starts bleeding, stop the medication, even if you haven’t completed the prescribed number of applications. Let everything heal and then start again for the remaining number of days.
I do recommend always AVOIDING the creases of the nose, because it always gets very irritated in that area just because it is warm and a bit moist, NOT because you have damage right there. Make sure you DO get the tops of your ears and take it ALL the way into the hairline, as we see lots of skin cancers developing there.
Because you get flaky while using topical 5-FU, you are going to be more sensitive to the sun. This is ONLY while you are using the medication, and it only matters if you are putting it on large amounts of skin, like your whole face. Avoid direct sunlight or use a sunscreen with an SPF of at least 30 while using this medication. If you are simply applying it to one spot, you don’t need to be AS careful, although we always recommend sun protection. You wouldn’t be needing this medication if the sun wasn’t doing damage to your skin!
Pairing With Calcipotriene
Even better than plain fluorouracil is to use it with a vitamin D cream called calcipotriene. Calcipotriene is a cream used for psoriasis because it helps regulate cells turning over, helping decrease the thick scaly areas you see in that skin disease. When used with fluorouracil, it shortens the duration of treatment to 4 days (8 days for thick areas like the scalp). It won’t be covered by your insurance unless you also have psoriasis, so if you are willing to pay $45 for the compounded version, we send in a prescription for fluorouracil WITH calcipotriene so you get both medicines in one mix for $45.
These creams are not a cure for precancers, so you’ll continue to acquire them. It just reduces the number and, by extension, reduces their ability to convert into full-blown skin cancers.
Have questions about fluorouracil, or want me to take a look at a spot? You can book online or call the office at 423-528-8833. This page is for general education, not a substitute for a personal exam.