How To Use Fluorouracil (5-FU) Eyedrops

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This information explains how to use fluorouracil (FLOOR-oh-YOOR-uh-sil) eyedrops. Fluorouracil eyedrops are often called 5-FU eyedrops.

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About 5-FU eyedrops

5-FU eyedrops are a chemotherapy (chemo) medicine used to treat neoplasias (NEE-oh-PLAY-zhuhs). Neoplasias are abnormal (not normal) cells in the eye. 5-FU eyedrops can also be used to heal scar tissue around the eye.

Your healthcare provider will prescribe 5-FU eyedrops and erythromycin (uh-rith-row-MY-sin) ointment. The ointment protects your skin from the 5-FU drops and is safe for your eyes.

Some people are allergic to erythromycin ointment. Instead, your healthcare provider will prescribe TobraDex® (tobramycin and dexamethasone mixture) ointment.

You can pick them up at:

Rockefeller Pavilion at 53rd Street
160 E. 53rd St., 3rd Floor Pharmacy
New York, NY 10022
Monday to Friday, to
646-888-0731

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Steps for using 5-FU eyedrops

  1. Clean your hands. Make sure they’re dry before using the ointment.
  2. Put a thin layer of ointment on the skin under the eye you’re getting treated (see Figure 1). Do not put it into your eye.
  3. Place one 5-FU drop in the affected eye.
  4. Wipe away any extra drops with a clean tissue. Then throw the tissue away.
  5. Clean your hands again.
Figure 1. Where to put ointment

Use the 5-FU eyedrops and erythromycin or TobraDex 4 times a day. Try to space these out evenly. For example, you can use them at breakfast, lunch, dinner, and before you go to bed.

At the end of each day, throw away the old 5-FU eyedrop bottle you used. Use a new bottle every day for 7 days.

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Side effects of 5-FU eyedrops

Your eye may feel irritated (for example, red, itchy, or burning) or dry after you use the 5-FU eyedrops. If it does, use over-the-counter lubricating (re-wetting) eye drops, such as Refresh®, Genteal®, or Systane®. You do not need a prescription to buy them.

Use the lubricating eye drops 10 minutes after putting the 5-FU drop into your eye. The 5-FU drops will not work as well if you put the lubricating drops in sooner.

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When to call your healthcare provider

Call your healthcare provider if you:

  • Get a rash around your eyes.
  • Have severe (very bad) pain or burning in your eyes.
  • Have blurry vision.

Go to the nearest emergency room if you:

  • Have trouble breathing.
  • Have severe swelling around your eyes.
  • Have severe vision changes.
  • Feel like your heart is beating very fast. This is rare.
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If you have questions or concerns, contact your healthcare provider. A member of your care team will answer Monday through Friday from to Outside those hours, you can leave a message or talk with another MSK provider. There is always a doctor or nurse on call. If you’re not sure how to reach your healthcare provider, call 212-639-2000.
If you have questions or concerns, contact your healthcare provider. A member of your care team will answer Monday through Friday from to Outside those hours, you can leave a message or talk with another MSK provider. There is always a doctor or nurse on call. If you’re not sure how to reach your healthcare provider, call 212-639-2000.

For more resources, visit www.mskcc.org/pe to search our virtual library.

How To Use Fluorouracil (5-FU) Eyedrops - Last updated on
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