Canada – PrTolak® Fluorouracil Cream 4%(w/w) fluorouracil (as fluorouracil sodium)

DIN 02485346

PrTolak ®
Fluorouracil Cream

4%(w/w) fluorouracil (as fluorouracil sodium)

What is Tolak® used for?

Tolak® is used in adults to treat actinic keratosis (AK) on the face, ears, or scalp. AK is a rough, crusty or scaly patch on the top layer of skin that is made up of fast growing precancerous cells.

It is not known if Tolak® is safe and effective in children.

How does Tolak® work?

Tolak® works by destroying the AK cells. The active ingredient in Tolak®, fluorouracil, enters the AK cells. This interrupts the function of the cell causing it to die.

As Tolak® destroys abnormal AK cells, the skin becomes irritated. The skin will return to normal within 4 weeks after stopping treatment.

What are the ingredients in Tolak®?

Medicinal ingredients: fluorouracil (as fluorouracil sodium)

Non-medicinal ingredients: arlacel-165, butylated hydroxytoluene, cetyl alcohol, anhydrous citric acid, glycerin, isopropyl myristate, methyl gluceth-10, methylparaben, peanut oil, propylparaben, purified water, sodium hydroxide, stearic acid, and stearyl alcohol.

Tolak® comes in the following dosage forms:

Cream, 4% (w/w)

Do not use Tolak® if:

  • You are pregnant or may become pregnant.
  • Females who are pregnant or plan to get pregnant:
    • Tolak® may harm your unborn child or may make you lose the pregnancy.
    • Before you start using Tolak®, a pregnancy test should be performed on all women who can get pregnant.
    • You should use effective methods of birth control while taking Tolak®. Keep using birth control for 1 month after the last time you use Tolak®.
    • Talk to your healthcare professional about methods of birth control that may be right for you during your treatment with Tolak®.
    • If you do become pregnant while taking Tolak®, stop using it and tell your healthcare professional right away.
  • Your body does not make enough of (you are deficient in) the enzyme called dihydropyrimidine dehydrogenase (DPD). If you do not have enough of this enzyme, you may get serious side effects if you use Tolak®. If you have stomach-area abdominal pain, bloody diarrhea, vomiting, fever, and chills, contact your healthcare professional right away. These may be signs that you are experiencing serious side effect of Tolak® use called systemic toxicity.
  • You are allergic to fluorouracil or any of other ingredients in this medicine. Tolak® contains peanut oil.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you use Tolak®. Talk about any health conditions or problems you may have, including if you:

  • Are breastfeeding or plan to breastfeed. It is not known if Tolak® passes into breast milk. You and your healthcare professional should decide if you will use Tolak® or breastfeed.
  • Are going to be exposed to sunlight, sun lamps, and tanning beds. Exposure to ultraviolet light immediately following application of Tolak® may cause severe sunburn.

Other warnings you should know about:

Avoid applying Tolak® in your eyes, mouth, lips, nostrils or other mucous membranes like the vagina. Irritation, inflammation and ulcers can occur in these areas after applying Tolak®.

Severe skin reactions may occur when using Tolak®. If you experience severe itching or eczema at the spot where you have applied Tolak® or somewhere else on your body, stop using Tolak®. Contact your healthcare professional right away.

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

The following may interact with Tolak®:

  • Medicines that affect how well the enzyme DPD works, like capecitabine, brivudine, sorivudine and interferon-α
  • A medicine called warfarin, which is used to prevent blood clots. You may experience bleeding complications if Tolak® is used with warfarin.
  • A medicine called phenytoin, which is used to treat seizures.
  • A medicine called leucovorin, which may be used in the treatment of some cancers. Leucovorin can increase the action and the side effects of Tolak®.

How to use Tolak®:

Always use Tolak® exactly as your doctor, pharmacist or nurse has told you. Check with your doctor, nurse or pharmacist if you are not sure.

  • Before applying Tolak®, gently wash, rinse and pat dry the skin areas to be treated.
  • Apply a thin layer of Tolak® to affected areas.
  • Gently massage evenly into your skin.
  • Use only on affected areas and not on skin that does not have actinic keratosis. Avoid transfer of Tolak® from your body to other people.
  • After applying Tolak®, wash your hands well.
  • Tolak® is for topical use only. Avoid use in your eyes, mouth, lips, nostrils or vagina.
  • Do not cover the treated areas with an airtight dressing after applying Tolak®.
  • Avoid sunlight. Tolak® can make your skin sensitive to the sun. You could get severe
    sunburn. Limit your time in the sun during treatment with Tolak®.

Usual dose:

Apply Tolak® to affected areas of skin once a day for 4 weeks.


In case of accidental ingestion, contact your health care professional, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.

Missed Dose:

If an application (dose) of this medication is missed, it is not necessary to make up the missed dose. Skip the missed dose and continue with the next scheduled dose.

What are possible side effects from using Tolak®?

These are not all the possible side effects you may feel when using Tolak®. If you experience any side effects not listed here, contact your healthcare professional.

  • Reactions at the application site (redness, scaling/dryness, swelling, crusting, breakdown of skin, stinging/burning, and itching).
  • Allergic contact dermatitis (severe itching or red rash at treated areas or other areas away from the treatment site).
  • Eye irritation
  • Eye swelling
  • Trouble sleeping

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, talk to your healthcare professional.

Reporting Side Effects

You can report any suspected side effects associated with the use of health products to Health Canada by:

  • Visit Adverse Reaction Reporting for information on how to report online, by mail or by fax; or
  • Calling toll-free at 1-866-234-2345.

NOTE: Contact your health professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.


Store Tolak® at 20°C to 25°C.

  • Do not freeze Tolak®.
  • Do not use Tolak® after the expiration date printed on the tube.

Keep out of reach and sight of children.

Medicines should not be disposed of down the drain or in household garbage. Ask your pharmacist how to dispose of medicines no longer required. These measures will help to protect the environment.

If you want more information about Tolak®:

  • Talk to your healthcare professional
  • Find the full product monograph that is prepared for healthcare professionals and includes the Patient Medication Information in the link below.

 Full Product Monograph