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5-Fluorouracil Treatment: What To Know

Updated: Aug 20, 2023

5FU Treatment
5FU Treatment

5-fluorouracil (FU) is a widely used topical medication that inhibits the growth of abnormal cells, making it a go-to option for actinic keratosis (pre-cancerous lesions) and certain types of skin cancer. Available in cream form, FU treatment offers easy application directly to the affected areas.

As a chemotherapy drug, FU therapy falls under the category of anti-metabolites. It works by interfering with the DNA synthesis process in rapidly dividing cells, ultimately leading to their destruction. When using this medicine, proper dosing and medical attention are crucial to ensure optimal care and minimize potential side effects.

At Mid-County Dermatology, a St. Louis Dermatology Center, we frequently recommend 5-fluorouracil cream to our patients, however, we educate and counsel them on the potential side effects they may experience during use. This article discusses some of the highlights that we bring up during a patient’s dermatology visit with us.

Uses of Fluorouracil Cream

Fluorouracil cream, also known as 5-fluorouracil treatment or topical fluorouracil, is a versatile medication used for various skin conditions. It is primarily prescribed to treat actinic keratosis, a precancerous skin condition caused by sun damage. It can be effective in treating basal cell carcinoma, squamous cell carcinoma, and other types of skin cancer.

One of the key advantages of fluorouracil cream is its application versatility. It can be used on different areas of the body such as the face, scalp, hands, arms, and other affected areas. This makes it an ideal treatment option for patients with multiple areas affected by these skin conditions.

The primary goal of using fluorouracil cream is to eliminate abnormal cells and promote healthy skin regeneration. When applied topically, the cream targets and destroys precancerous or cancerous cells on the surface of the skin. By doing so, it helps prevent further progression of these conditions and facilitates the growth of new healthy tissue.

Actinic keratosis is a common dermatologic condition that affects individuals who have been exposed to excessive sunlight over time. These rough patches often appear on sun-exposed areas such as the face and hands. Topical fluorouracil cream effectively treats actinic keratosis by targeting these abnormal cells and causing them to die off. Over time, new healthy skin replaces the damaged cells, providing relief from facial irritation caused by this dermatologic condition.

In addition to actinic keratosis treatment, fluorouracil cream has proven effective in managing basal cell carcinoma and squamous cell carcinoma - two common forms of skin cancer. When applied directly to cancerous lesions under medical supervision, this topical treatment can help destroy cancer cells without invasive procedures like surgery or radiation therapy.

It's important to note that fluorouracil cream should only be used under dermatologic guidance due to potential side effects such as redness, swelling, and skin irritation. The treatment duration can vary depending on the severity of the condition being treated. Patients should closely follow their dermatologist’s instructions regarding application frequency and duration.

Clinical Features of Actinic Keratosis (AK)

Actinic keratosis, also known as solar keratoses, is a common skin condition characterized by rough, scaly patches that typically appear on sun-exposed areas such as the face and scalp. These patches may manifest as red or brown spots with a sandpaper-like texture.

One of the prominent clinical features of actinic keratosis is the potential for irritation and discomfort in the affected areas. Individuals with AK lesions often experience itching, a burning sensation, or tenderness. This can be particularly bothersome when the lesions are located on sensitive regions like the eyelids.

While actinic keratosis itself is not considered a form of skin cancer, it is crucial to recognize its significance about more severe dermatologic conditions. If left untreated, actinic keratosis has the potential to progress into invasive squamous cell carcinoma (SCC), a type of skin cancer.

The progression from actinic keratosis to squamous cell carcinoma underscores the importance of early detection and treatment. Regular monitoring and evaluation by a dermatologist can help identify any changes in AK lesions that may indicate malignant transformation into SCC.

To mitigate the risk associated with actinic keratosis and prevent its progression into skin cancer, various treatment options are available. One commonly used treatment method involves using topical creams containing 5-fluorouracil (5-FU). This cream works by selectively targeting abnormal cells within AK lesions while sparing healthy surrounding tissue.

When applied to affected areas, 5-fluorouracil cream induces an inflammatory response that leads to the destruction of precancerous cells within actinic keratoses. Over time, this process results in the elimination of these unsightly and potentially harmful lesions.

It is important to note that during 5-fluorouracil treatment, some individuals may experience temporary side effects such as redness, swelling, and crusting of the skin. These reactions are typically transient and indicate that the medication is effectively targeting the abnormal cells.

In addition to 5-fluorouracil cream, other treatment options for actinic keratosis include cryotherapy (freezing), photodynamic therapy (light-based treatment), chemical peels, and laser therapy. The choice of treatment depends on factors such as lesion size, location, and individual patient characteristics.

How to Apply Fluorouracil Cream

To effectively apply 5-fluorouracil cream for treatment, it is crucial to follow a few simple steps. By properly cleansing the affected area and using an appropriate applicator, you can ensure that the cream is applied evenly and absorbed into the skin for optimal results.

Cleanse the affected area thoroughly before application

Before applying fluorouracil cream, it is essential to cleanse the affected area thoroughly. Gently wash the area with mild soap and water, ensuring that any dirt or debris is removed. Pat dry with a clean towel to avoid any irritation caused by rubbing.

Use fingertips or a non-metal applicator to apply a thin layer of cream onto the lesion(s)

Once the area is cleansed and dry, it's time to apply the 5-fluorouracil cream. You can use your fingertips or a non-metal applicator for this step. It's important not to use metal applicators as they may react with the medication.

Take a small amount of cream and gently apply it in a thin layer over the lesion(s) you are treating. Make sure to cover all areas evenly, but avoid applying excessive amounts of cream as it may lead to unnecessary irritation.

Gently rub the cream until it disappears into the skin

After applying the fluorouracil cream, gently rub it into your skin using circular motions until it disappears completely. This ensures that the medication is absorbed properly and penetrates deep into the affected cells.

By massaging in this way, you enhance its effectiveness while also promoting better absorption without leaving any residue on your skin surface.

Wash hands immediately after applying unless treating hand lesions

It's crucial to wash your hands immediately after applying 5-fluorouracil cream unless you are specifically treating hand lesions. This prevents unintentional transfer of medication to other areas of your body or contact with sensitive areas such as your eyes or mouth.

Remember to use soap and water when washing your hands thoroughly, ensuring that any residue is removed. This step helps minimize the risk of accidental exposure to the medication.

Side Effects of Fluorouracil Treatment

Fluorouracil is a commonly used medication for various skin conditions, such as actinic keratosis and certain types of skin cancer. While it can be highly effective in treating these conditions, it is important to be aware of the potential side effects that may occur during treatment. Here are some key points to keep in mind:

  • Common side effects: When undergoing fluorouracil treatment, it is not uncommon to experience redness, swelling, crusting, and peeling at the application site(s). These are typically temporary and subside once the treatment is completed. It's important to note that these side effects indicate that the medication is working as intended.

  • Temporary discomfort: Along with visible changes at the application site(s), some individuals may also experience temporary discomfort during treatment. This can manifest as a burning or stinging sensation on the skin. While this sensation can be unpleasant, it usually resolves within a short period.

  • Rare but possible side effects: Although rare, there are potential side effects associated with fluorouracil treatment that require attention. Allergic reactions may occur in some individuals, leading to symptoms such as itching, rash, or hives. Infection at the treated area(s) is another rare but possible complication that should be monitored closely.

  • Reporting severe or persistent side effects: It is crucial to inform your healthcare provider about any severe or persistent side effects you may experience during fluorouracil treatment. While most side effects are mild and transient, there could be instances where they become more severe or prolonged. By communicating openly with your healthcare provider, they can provide appropriate guidance and support.

When considering potential adverse effects from fluorouracil treatment, it's essential to understand that individual experiences may vary. The majority of patients tolerate the medication well without significant issues; however, being aware of possible side effects empowers you to take appropriate action if needed.

Managing Side Effects of Fluorouracil

Fluorouracil is a commonly used chemotherapy medication for treating various types of cancer. While it can be highly effective in fighting cancer cells, it may also cause side effects that can impact the patient's quality of life. To ensure a smoother treatment experience, it is important to manage these side effects effectively. Here are some practical tips for managing the side effects of fluorouracil treatment:

Alleviating Dryness and Minimizing Discomfort

One common side effect of fluorouracil treatment is dryness of the skin, particularly in the treated areas. This can lead to itching, redness, and discomfort. To alleviate dryness and minimize discomfort, it is recommended to apply a moisturizer or emollient cream regularly. These products help hydrate the skin and create a protective barrier against further moisture loss.

Sun Protection during Treatment

Excessive sun exposure can worsen the side effects of fluorouracil treatment, including increased sensitivity to sunlight and heightened risk of sunburns. It is crucial to avoid prolonged sun exposure and protect your skin with sunscreen that has a high SPF (Sun Protection Factor). Apply sunscreen generously before going outdoors, even on cloudy days, and reapply as needed throughout the day.

Temporary Discontinuation for Severe Side Effects

In some cases, severe side effects may occur during fluorouracil treatment that significantly affects a patient's well-being. If you experience severe symptoms such as persistent nausea or vomiting, severe diarrhea, unexplained bleeding or bruising, or any other concerning signs, consult your healthcare provider immediately. They may recommend temporary discontinuation of the treatment until your body recovers from these adverse reactions.

Consult Your Dermatologist for Guidance

Each individual may react differently to fluorouracil treatment due to variations in factors such as overall health condition and tolerability. Therefore, it is essential to maintain open communication with your dermatologist throughout the treatment process. They can provide personalized guidance on managing specific side effects and offer recommendations tailored to your needs.

Monitoring and Regular Dosing Schedule

To ensure the best possible outcome from fluorouracil treatment, it is crucial to follow a regular dosing schedule as prescribed by your dermatologist. This ensures that the medication remains effective in targeting cancer cells while minimizing potential side effects.

Precautions and Guidelines for Fluorouracil Cream

Before starting your 5-fluorouracil treatment, it is essential to be aware of certain precautions and guidelines. By following these recommendations, you can ensure the safe and effective use of fluorouracil cream.

Inform your dermatologist about any allergies or medical conditions before starting treatment. It is crucial to disclose any known allergies, especially if you have experienced a reaction to medications in the past. Inform your healthcare provider about any existing medical conditions you may have, as this information will help them determine if fluorouracil cream is suitable for you.

Pregnant or breastfeeding individuals should consult their doctor before using fluorouracil cream. The effects of this medication on unborn babies or infants through breast milk are not yet fully understood. Therefore, it is essential to discuss the potential risks and benefits with your healthcare provider before initiating treatment.

When applying the cream, avoid contact with eyes, mouth, nose, and other mucous membranes. Fluorouracil cream is intended for external use only and should not come into contact with sensitive areas such as the eyes or mucous membranes. If accidental contact occurs, rinse thoroughly with water and seek medical attention if necessary.

Do not cover the treated area(s) with bandages unless instructed by your healthcare provider. While using fluorouracil cream, it is generally recommended to leave the treated areas uncovered. However, in some cases where directed by your healthcare provider, they may advise covering the area(s) with bandages for enhanced efficacy or protection.

If you experience severe skin irritation or adverse reactions during treatment, contact your dermatologist immediately. While mild skin reactions are common when using fluorouracil cream—such as redness, dryness, and itching—it is important to monitor your skin closely throughout treatment. If you notice severe discomfort or unexpected side effects like blistering or excessive pain, seek medical advice promptly.

In case of accidental ingestion, contact a poison control center or the advice line provided by your healthcare provider. Although fluorouracil cream is not meant to be ingested, accidents can happen. If you accidentally swallow the cream, it is crucial to seek immediate assistance from a poison control center or call the advice line provided by your healthcare provider.

By adhering to these precautions and guidelines, you can minimize potential risks and ensure a safe experience with 5-fluorouracil treatment. Remember to consult your dermatologist provider for personalized advice based on your specific circumstances and follow their instructions diligently throughout your treatment journey.

Storage and Disposal of Fluorouracil Cream

There are a few important guidelines to keep in mind. Proper storage ensures the effectiveness of the medication, while appropriate disposal prevents any potential harm to others or the environment.

Store at Room Temperature

To maintain the potency of your fluorouracil cream, it is crucial to store it correctly. Keep the cream at room temperature, away from heat sources and direct sunlight. Extreme temperatures can alter its composition and reduce its effectiveness. Therefore, avoid storing it in places like bathrooms or near windows where temperature fluctuations may occur.

Keep Out of Reach

Fluorouracil cream should always be kept out of reach of children and pets. Accidental ingestion can have serious consequences, so make sure to store it in a secure location where they cannot access it. If accidental ingestion does occur, seek immediate medical attention.

Follow Local Guidelines for Disposal

Proper disposal of unused or expired medication is essential for both safety and environmental reasons. Different regions may have specific guidelines regarding medication disposal, so it is important to follow local regulations.

Consult your pharmacist or dermatologist for guidance on how to dispose of fluorouracil cream correctly. They will provide you with information specific to your area that ensures compliance with local regulations.

Do Not Flush Down the Toilet or Pour into Drains

Under no circumstances should you flush fluorouracil cream down the toilet or pour it into drains unless explicitly instructed otherwise by your healthcare professional or pharmacist. Flushing medications down the toilet can contaminate water sources and harm aquatic life.

Instead, consider these options for proper disposal:

  • Take-back programs: Many communities organize take-back programs where you can safely dispose of unused medications.

  • Medication drop-off sites: Some pharmacies or healthcare facilities have designated collection points for safe medication disposal.

  • Household trash: If no other options are available, mix the cream with an undesirable substance like coffee grounds or cat litter before sealing it in a plastic bag and disposing of it in the regular household trash.

Conclusion: 5-Fluorouracil Treatment

In conclusion, 5-fluorouracil treatment is a powerful option for addressing various skin conditions such as actinic keratosis. This topical cream offers several benefits, including its effectiveness in treating pre-cancerous lesions and reducing the risk of skin cancer development. By following proper application techniques and adhering to precautions, you can maximize the benefits of 5-fluorouracil treatment while managing potential side effects.

To begin with, understanding the uses of fluorouracil cream is essential. It is primarily employed in treating actinic keratosis (AK), a common condition caused by excessive sun exposure that can progress to skin cancer if left untreated. Fluorouracil cream effectively targets these precancerous lesions, helping to prevent their progression and reduce the risk of developing more severe forms of skin cancer.

Knowing how to apply fluorouracil cream correctly is crucial for achieving optimal results. Applying a thin layer of the cream to clean, dry skin twice daily ensures proper absorption and efficacy. It's important to follow your healthcare provider's instructions regarding treatment duration and frequency.

While undergoing fluorouracil treatment, it's essential to be aware of potential side effects. These can include redness, swelling, crusting, or even temporary discoloration of the treated area. However, by managing these side effects with appropriate care and monitoring your skin's response throughout the treatment process, you can minimize discomfort and achieve successful outcomes.

To manage side effects effectively, consider employing simple strategies such as applying a moisturizer or sunscreen during treatment or using cold compresses to alleviate any discomfort or inflammation. Consulting with your healthcare provider about any concerns or unexpected reactions will also ensure that you receive appropriate guidance tailored to your specific needs.

It is vital to adhere to precautions and guidelines when using fluorouracil cream. Avoiding contact with eyes, nose, mouth, and open wounds is crucial to prevent irritation or adverse effects. Ensuring proper storage and disposal of the cream according to the instructions provided helps maintain its potency and prevents any accidental misuse.

In conclusion, 5-fluorouracil treatment offers an effective solution for addressing actinic keratosis and reducing the risk of skin cancer development. By understanding its uses, applying it correctly, managing side effects, and following precautions diligently, you can make the most out of this treatment option. Remember to consult with your healthcare provider for personalized advice and guidance throughout your treatment journey.


Can I use fluorouracil cream for other skin conditions?

Fluorouracil cream is specifically formulated for treating actinic keratosis (AK) and should only be used as directed by your healthcare provider. It may not be suitable or effective for other skin conditions.

How long does it take to see results from fluorouracil treatment?

The time taken to observe visible results can vary depending on individual factors such as the severity of the condition being treated. Typically, improvement in AK lesions can be observed within a few weeks of starting fluorouracil treatment.

Can I apply makeup while using fluorouracil cream?

It is generally recommended to avoid applying makeup over areas where you have applied fluorouracil cream. Makeup may interfere with the absorption and effectiveness of the medication.

Is it normal for my skin to become red and irritated during treatment?

Yes, mild to moderate redness and irritation are common side effects of fluorouracil treatment. However, if you experience severe or prolonged discomfort or notice any concerning changes in your skin's appearance during treatment, it is essential to contact your healthcare provider.

Will my insurance cover the cost of fluorouracil cream?

Coverage varies depending on your insurance plan. It is advisable to check with your insurance provider regarding coverage details and any potential out-of-pocket expenses associated with fluorouracil treatment.

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