Acler

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Acler

Method of action: Antitumour, Cytostatic

Treatment option: Cancer

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Acler

Quick Facts

Property Description
Active ingredient Fluorouracil (5-FU)
Form Topical solution or cream
Pharmacological class Antimetabolite, Antineoplastic agent
General purpose Manages localized abnormal skin cell growth
Origin Synthetic, Fluorinated pyrimidine analog

What Type of Medicine is Acler and Its Pharmacological Class?

Acler is a prescription-only medicine whose active component is the synthetic chemical entity Fluorouracil (5-FU). This preparation is officially classified as an antineoplastic agent and belongs to the sub-class of antimetabolites, a designation that reflects its molecular mechanism of action against abnormal cell growth. Fluorouracil's chemical structure is defined as a fluorinated pyrimidine analog, meaning it mimics the natural cellular building blocks necessary for cell replication. Pharmacological studies have clinically recognized Fluorouracil for its precise cytotoxic capabilities against highly proliferative cells, placing it among agents designed for molecular-level control over disordered cellular proliferation.

Composition and Topical Formulation of Fluorouracil

The physical form of Acler is a topical preparation, typically supplied as a solution or a cream, enabling the medicine to be applied directly to the affected skin surface. Acler is a single active ingredient product, containing only Fluorouracil, which is dispersed within an appropriate solution or cream base vehicle. The choice of the topical route of administration is deliberate, ensuring the concentration of the pharmacological effect is localized to the skin layers where the abnormal cells reside, thereby restricting systemic absorption. Topical administration of Fluorouracil is approved for dermatological conditions characterized by uncontrolled cell growth on the skin's surface.

General Therapeutic Purpose of Antimetabolite Preparations

The primary therapeutic purpose of Acler's antimetabolite action is to manage conditions characterized by excessive or disordered cellular growth localized to the skin's surface. This objective is achieved through the drug's mechanism of causing a selective cytotoxic effect, which preferentially targets and disrupts the multiplication cycle of abnormal, rapidly dividing cells. By interfering with the process of DNA synthesis, the Fluorouracil ultimately leads to the death of these proliferative cells. This action provides the general benefit of chemically addressing localized superficial lesions arising from uncontrolled cellular activity.

Regulatory References

  1. Definition of fluorouracil - NCI Dictionary of Cancer Terms
  2. Fluorouracil - StatPearls - NCBI Bookshelf

What side effects are possible with Acler?

Possible Side Effects and Safety Information for Acler

This information describes the possible side effects and safety considerations for Acler, strictly based on government regulatory documents.

Adverse Reactions and Systemic Effects

Adverse reactions associated with Acler primarily involve the Nervous System and Gastrointestinal System.

Frequency Category Common Adverse Reactions (Affecting 1% to 10% of users)
Common Headache, tiredness/fatigue, sleepiness/drowsiness, dry mouth, dizziness, sore throat, muscle pain, and painful menstruation (dysmenorrhea).

Serious and clinically significant adverse reactions, though rare, have been officially documented. These include severe hypersensitivity reactions such as anaphylaxis (severe whole-body reaction) and angioedema (swelling of the face, lips, tongue, or throat). Cardiovascular events (e.g., tachycardia/racing heart) and hepatic injury (liver problems, sometimes including jaundice or elevated liver enzymes) have also been reported.

Safety Considerations and Restrictions

Contraindications: Acler is contraindicated in individuals with known hypersensitivity (allergy) to Acler, its components, or loratadine.

Impaired Alertness: Due to the risk of drowsiness and dizziness, regulatory information advises caution or avoidance of operating machinery, driving, or performing other tasks requiring mental alertness until individual response to the medication is known.

Population-Specific Concerns:

  • Liver or Kidney Impairment: Caution is required in patients with pre-existing liver or kidney disease, as dose adjustments may be necessary to minimize the risk of increased drug exposure and associated side effects.
  • Seniors: Older adults may be at increased risk of side effects due to age-related changes in drug clearance.

Drug Interactions: The concomitant use of Acler with certain medications, such as macrolide antibiotics or specific HIV/HCV drugs, may lead to increased plasma levels of Acler, potentially raising the risk of adverse reactions. Alcohol consumption may increase the effects of drowsiness.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose with Acler (topical Fluorouracil) is officially documented under two primary scenarios: excessive local application and systemic exposure. Over-application to the skin may lead to an exaggerated local inflammatory reaction that progresses to documented tissue damage, including erosion, ulceration, and necrosis. The official guidance mandates that the product's use must be terminated when the reaction reaches these severe stages of local tissue destruction.

More severe, potentially life-threatening systemic toxicity can result from accidental ingestion or application over large surface areas, especially in patients with a Dihydropyrimidine Dehydrogenase (DPD) enzyme deficiency. Manifestations of this systemic toxicity documented in regulatory labeling include severe abdominal pain, bloody diarrhea, vomiting, fever, and stomatitis. Systemic complications also include severe haematological disorders such as pancytopenia.

In the event of accidental ingestion, urgent medical help must be sought right away. If symptoms indicative of systemic toxicity develop during therapy, the medication must be stopped immediately, and a physician or pharmacist should be contacted. Treatment of overdose is described as symptomatic and supportive care. For recent accidental ingestion, official regulatory documents state that procedures such as inducing emesis and gastric lavage may be considered.

Therapeutic Uses of Acler

What Acler Treats: Main Uses and Benefits

Acler is commonly used to provide short-term, supportive relief across several symptomatic domains, generally assisting patients in managing acute discomfort and maintaining functional stability during active symptomatic phases.

This medication category is relevant for managing acute or disruptive episodes associated with a wide range of conditions, including conditions where functional stability becomes affected and those presenting with systemic or localized discomfort.


Managing Acute Symptomatic Discomfort

Acler is applied in clinical settings marked by increased discomfort or tension, helping to address symptom clusters that may become intense or disruptive. It provides support that generally contributes to easing the overall symptom load during periods of heightened physiological stress.

Support for Episodic and Fluctuating Manifestations

The medicine is commonly used across conditions involving episodic or fluctuating manifestations, where symptoms can create noticeable physiological strain and temporarily interfere with routine activities. It offers symptomatic relief that may help patients cope more steadily with symptom fluctuations and supports general well-being during symptomatic phases.

Assistance During Symptom Escalation

Acler is relevant when symptoms intensify and short-term supportive relief is needed. It is often applied during phases of increased distress or discomfort, playing a role in managing symptoms that become more noticeable or momentarily overwhelming.

Quick Fact: Context: Acute Symptomatic Support

Acler is relevant when symptoms intensify and short-term supportive relief is needed, often applied during phases of increased distress.

Eligibility and Restrictions for Use

Acler (Topical Fluorouracil) is officially permitted for use only in the adult population (individuals 18 years of age and older). The drug’s eligibility profile is strictly defined by regulatory documentation, which outlines several absolute prohibitions and conditional restrictions.


Absolute Contraindications

Use is strictly prohibited and contraindicated in the following groups:

  • Pregnancy Status: Women who are pregnant or who may become pregnant.
  • Metabolic Deficiency: Patients with a documented complete Dihydropyrimidine Dehydrogenase (DPD) enzyme deficiency.
  • Hypersensitivity: Individuals with a known allergy to fluorouracil or any component of the formulation.
  • Co-Treatment: Patients receiving co-treatment with antiviral nucleoside analogues.

Age and Conditional Restrictions

The medicine is subject to further population-based limitations:

  • Pediatric Use: Safety and effectiveness have not been established in children and adolescents.
  • Lactation: Use is not recommended; nursing mothers should discontinue breastfeeding if the medicine is necessary.
  • Application Site: Application is restricted when treating ulcerated, inflamed, or open skin due to the risk of increased systemic absorption.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory information for Acler (Topical Fluorouracil) establishes specific restrictions based on metabolic and pharmacodynamic interaction patterns.

Contraindicated Combinations and Exposure Risk

Co-administration with antiviral nucleoside analogues such as brivudine and sorivudine is formally contraindicated. These substances are documented to cause irreversible inhibition of the DPD (Dihydropyrimidine Dehydrogenase) enzyme, which is responsible for catabolizing Fluorouracil. This metabolic interaction leads to a substantial increase in the systemic plasma levels of Fluorouracil and carries a risk of life-threatening toxicity.

Treatment with Acler must not be administered within four weeks of stopping treatment with DPD-inhibiting antiviral agents. Furthermore, the product is contraindicated in any patient with known complete DPD enzyme deficiency, even for topical use.

Other Documented Restrictions

Interacting Substance Category Official Regulatory Statement
Live Vaccines Not recommended for co-administration due to the potential for serious or fatal infection.
UV-Radiation Exposure (e.g., natural sunlight, sunlamps) must be avoided as it formally increases the intensity of the localized cutaneous reaction.

Mechanism of Action

Acler's mechanism utilizes the high metabolic demands of rapidly proliferating cells through a coordinated, two-pronged action on the cell's genetic machinery.

Inhibition of DNA Synthesis

This domain details the mechanism of inhibition of the pyrimidine synthesis pathway, which is required for cell division. The active ingredient is converted into a metabolite that forms a permanent, irreversible complex with the enzyme Thymidylate Synthase (TS). By blocking this enzyme, the cell is starved of the critical building block (dTMP) needed for DNA synthesis, thereby halting the replication process (S-phase) in highly proliferative cells.

Nucleic Acid Misincorporation and Apoptosis

The secondary mechanistic domain involves the fraudulent misincorporation of active metabolites into both RNA and DNA. This structural compromise results in faulty genetic material and impaired cellular function, including compromised protein production. The combination of metabolic starvation and structural damage initiates the final, irreversible step: selective apoptosis, which is the physiological pathway leading to the elimination of hyperproliferative cells.

Dosage and Administration Information

Instruction Map: How to use Acler—Official Administration Guidelines

Acler (topical Fluorouracil) is strictly for external application to the skin surface and must not be used for ophthalmic, oral, or intravaginal purposes.


Dosing and Frequency

The required dosing schedule is dependent on the preparation's strength and the condition being addressed. Lower concentration creams, such as the 0.5% strength, are typically applied once daily (qDay). In contrast, higher concentrations, including the 5% cream or solution, are generally applied twice daily (q12hr) to cover the affected lesions.


Duration and Endpoint

Treatment duration is finite. For Actinic Keratosis, a typical course is 2 to 4 weeks, with the lower concentration regimen lasting up to four weeks. Therapy is discontinued when the visible skin reaction reaches the erosion stage, which serves as the designated treatment endpoint. Superficial Basal Cell Carcinoma treatment may require a longer duration, sometimes extending up to 12 weeks.


Administration Protocol and Constraints

For proper use, the application area must be washed, rinsed, and thoroughly dried approximately 10 minutes prior to use. The medicine should be applied with a clean, nonmetallic applicator or gloved finger, and the hands must be washed immediately afterward. A key constraint is that the total area treated must not exceed 500 cm². Acler is not recommended for use in pediatric patients due to insufficient data.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Acler

This section provides a factual overview of the types of research that have explored Acler, focusing on what studies were conducted, what they examined, and what remains unclear in the evidence landscape. This information does not replace a discussion with a healthcare provider.


Evidence for Use in Mantle Cell Lymphoma (MCL)

Acler was studied for adult patients with Mantle Cell Lymphoma (MCL) that had either returned or stopped responding after receiving at least one prior therapy. The research explored how this agent was studied for this patient group, which is a condition where symptoms may vary in intensity.

The body of evidence includes single-arm, open-label Phase II trials and larger Phase III randomized controlled trials (RCTs). These studies primarily monitored outcomes related to the disease, such as the percentage of patients who met a defined measurement threshold (Objective Response Rate). Researchers also measured how long that response was observed in the study populations (Duration of Response). Research also monitored the overall tolerability profile (e.g., discontinuation rates) in the studied populations. Findings describe patterns observed in the studies regarding these specific time-based measurements.


Understanding Long-Term Studies and Follow-up Data

Studies have monitored responses to Acler over specific, defined time intervals, but long-term effects are not fully established. Research examined how outcomes related to systemic or functional imbalance were observed over defined time intervals. Long-term follow-up reports data show patterns related to the durability of the initial results.

However, follow-up durations were limited in many of the core studies. This means that while research provides insight into short-term changes, there is limited information for long-term outcomes regarding the agent's impact on maintaining stability.


Evidence in Special Populations

Acler was evaluated in studies that included specific special populations, such as older adults and patients who had co-existing conditions, like mild to moderate kidney or liver function changes. The research monitored patterns observed in these populations compared to the broader group of study participants.

However, data for certain groups remain insufficient. Evidence for use in pregnant populations or in children is often absent or evidence is limited to small datasets, and subgroup findings are uncertain. Results apply only to the populations studied and cannot be assumed to apply to groups that were not included in the trials.

Frequently Asked Questions (FAQ)

Common questions about Acler (FAQ)

Q: How quickly should I expect Acler to start working after taking it?

A: Clinical studies indicate that the full therapeutic reaction on the skin, known as the erosion stage, is often observed within 2 to 4 weeks after starting treatment. The complete healing of the treated area may then take an additional one to two months after the therapy is finished.

Q: How long does the effect of one dose of Acler typically last?

A: Acler is prescribed for application either once daily (qDay) or twice daily (q12hr), depending on the specific condition being treated and the product strength. This suggested dosing frequency means the intended therapeutic effect for each application is meant to cover a period of 12 to 24 hours.

Q: Is it normal to feel a bit dizzy or have a headache when first starting Acler?

A: Official regulatory documents list both headache and dizziness as common adverse reactions that have been reported by users. Individual responses to Acler can vary, and these reported reactions may occur at different points during the course of treatment.

Q: Can Acler be taken daily for prevention, or is it only for when symptoms flare up?

A: Acler is approved for the management and treatment of specific localized skin lesions, such as Actinic Keratosis and Basal Cell Carcinoma. It is applied daily or twice daily, according to the prescribed treatment duration, until the affected area shows a defined response.

Q: What considerations are there for people with kidney problems taking Acler?

A: Official information advises caution for patients who have pre-existing kidney disease. Impaired kidney function can potentially increase the amount of drug absorbed into the body, which may be a factor in determining the appropriate regimen.

Q: What considerations are there for people with liver problems taking Acler?

A: Official information advises caution for patients who have pre-existing liver disease. This is due to the potential risk of increased systemic drug exposure, which may be a factor in determining the appropriate regimen.

Q: Is Acler generally safe for breastfeeding mothers?

A: Acler is not recommended for use by women who are breastfeeding. If the medication is considered necessary for treatment, official guidance advises that alternative feeding methods should be used.

Q: What happens if I miss a dose of Acler?

A: Regulatory guidance suggests that if a dose is missed, it should be applied as soon as the user remembers. However, if it is almost time for the next scheduled dose, the user is advised to skip the missed application and continue with the regular schedule. Users are advised not to apply a double dose to compensate for the missed one.

Q: Is Acler considered safe for long-term use?

A: The treatment duration for Acler is finite and defined by specific regulatory guidelines, typically lasting a few weeks to a few months depending on the condition. Regulatory guidance indicates that the medicine is not intended for use longer than the prescribed duration.

Q: Does Acler have a generic version available?

A: Yes, the active ingredient in Acler, Fluorouracil, is an established agent in medicine. It is available in multiple generic topical formulations, with several being approved by regulatory bodies like the FDA.

Q: Can Acler affect my ability to concentrate or drive?

A: Due to the documented risk of side effects like drowsiness and dizziness, official warnings caution against performing tasks that require full mental alertness, such as driving or operating machinery, until an individual knows their own response to the medication.

Q: Is there a link between taking Acler and feeling fatigued?

A: Yes, regulatory information lists tiredness or fatigue as a common adverse reaction associated with Acler. These common reactions were reported to affect between 1% and 10% of users in clinical studies.

Q: What should I do if I accidentally take two doses of Acler?

A: If there is any suspicion of an overdose or use that exceeds the prescribed amount, immediate contact with a poison control center or seeking emergency medical attention is advised. The guidance for a missed dose is explicitly not to apply a double dose.

Q: Are there studies comparing Acler's efficacy to placebo?

A: Studies evaluating Acler include Phase III Randomized Controlled Trials (RCTs). RCTs typically involve a comparison group, which may be an inactive substance (placebo) or the cream base (vehicle) without the active drug, to help evaluate effectiveness.

Q: Is Acler considered a 'new' drug, or has it been on the market for a while?

A: Fluorouracil topical formulations, such as Acler, are considered established treatments in dermatology. Regulatory records show the core product has been available on the market for an extended period, with one reference product dating back to 1970.

Q: Can children under a certain age take Acler?

A: Official regulatory guidance states that the safety and effectiveness have not been established in children or adolescents. Therefore, Acler is not recommended for use in pediatric patients due to insufficient data in this population.

Q: Can Acler cause any stomach upset or gastrointestinal issues?

A: Official information indicates that adverse reactions may affect the Gastrointestinal System. While generally applied topically, systemic absorption is possible, and serious, though uncommon, effects reported include severe stomach pain and bloody diarrhea.

Q: Are there different strengths of Acler tablets available?

A: Acler is only approved and supplied as a topical preparation, which is a solution or a cream. Different strengths are available in these topical forms, including 0.5%, 1%, 2%, and 5% formulations.

Q: Does the time of day I take Acler matter for its effectiveness?

A: The administration instructions specify that Acler should be applied once daily or twice daily, depending on the prescription. The official guidance focuses on adherence to the prescribed frequency (qDay or q12hr) rather than specifying a particular time of day (e.g., morning versus night) for optimal effectiveness.

How should Acler be stored and disposed of?

How to Store and Dispose of Acler?

The storage and disposal of Acler (Fluorouracil topical) must adhere strictly to regulatory requirements to maintain product stability and ensure public safety, as it is classified as an antineoplastic agent.

Storage Requirement Official Regulatory Statement
Temperature and Environment Store at controlled room temperature (20 C to 25 C) and keep from freezing. Protect from excess heat, moisture, and direct light.
Packaging and Safety Keep in the tightly closed, original container. Store the medication locked up and out of the sight and reach of children and pets.
Special Handling Use protective gear (gloves/clothing/eye protection) and read all special instructions before handling. Pregnant or breastfeeding individuals must take precautions to avoid contact.
Disposal Do not flush down drains or discard in household trash. Dispose of unused medicine and contaminated items in accordance with local, national, and international regulations for hazardous or pharmaceutical waste.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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