Fimer

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Fimer

Treatment option: Colorectal Cancer, Cancer

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Fimer

Fimer is a synthetic antineoplastic agent and fixed-dose combination product used in supportive strategies to interfere with the rapid division of specific cells. It is administered orally and consists of two active ingredients, Tegafur and Uracil, which work together to maximize the availability of the active chemotherapy agent, 5-Fluorouracil (5-FU), within the body.

Quick Facts Description
Active Ingredients Tegafur and Uracil
Form Oral Capsule
Pharmacological Class Antineoplastic Agent, Antimetabolite
Origin Synthetic Pyrimidine Analogue

What Type of Drug is Fimer (Tegafur-Uracil)?

Fimer belongs to the pharmacological class of Antimetabolites and is specifically categorized as a synthetic pyrimidine analogue. It is one of the second-generation oral fluoropyrimidines, representing an advancement from older intravenous treatments by providing a convenient method for systemic drug delivery. This oral formulation simplifies administration and helps maintain a sustained level of the active component in the body. The general therapeutic purpose of this medication is to support established medical approaches that target and inhibit the uncontrolled proliferation of cells, a strategy commonly recognized in oncology.


The Components and Form of Fimer

The composition of Fimer is a specialized two-part system featuring the active ingredients Tegafur and Uracil, typically provided as a capsule for oral administration. Tegafur is included as a prodrug that requires bioactivation to generate the potent chemotherapy agent, 5-Fluorouracil (5-FU). Uracil acts as an enzymatic inhibitor by suppressing the natural enzyme, dihydropyrimidine dehydrogenase (DPD), which normally degrades 5-FU. The inclusion of Uracil ensures that a higher, more consistent concentration of the active agent remains available to reach its targets.


How Does Fimer Function at a High Level?

Fimer achieves its effect through a protected dual-action mechanism that controls the release and breakdown of the active component. The combined action of Tegafur and Uracil ensures that 5-FU is not rapidly neutralized, thereby allowing the active agent to perform its function. The final effect involves the 5-FU component interfering with the synthesis of genetic materials (DNA and RNA) in quickly multiplying cells. This interference is crucial for disrupting the abnormal growth and reproduction cycle, serving the overall therapeutic intent of the antineoplastic agent.

What side effects are possible with Fimer?

Fimer: Possible Side Effects and Safety Information

The safety profile of Fimer (Tegafur-Uracil) is officially documented by regulatory authorities, classifying adverse reactions according to their frequency and the physiological systems affected. Adverse events are primarily related to the cytotoxic effects of the active component, 5-Fluorouracil, on rapidly dividing cells.

Adverse Reaction Classification

Official labeling describes reactions across several System-Organ Classes, including Blood and Lymphatic System Disorders (myelosuppression), Gastrointestinal Disorders, Skin and Subcutaneous Tissue Disorders, and Nervous System Disorders.

Frequency Category Examples of Officially Listed Reactions
Very Common / Common Neutropenia (low white cell count), Diarrhoea, Nausea, Vomiting, Stomatitis (mouth sores), Fatigue, and Anaemia.
Uncommon / Rare Pancytopenia, Febrile neutropenia, Alopecia, and serious reactions involving Cardiotoxicity (e.g., myocardial infarction, arrhythmias).

Serious Safety Constraints and Special Populations

Specific regulatory constraints exist regarding the use of Fimer. The medication is contraindicated (must not be used) in individuals with a complete deficiency of the enzyme Dihydropyrimidine Dehydrogenase (DPD), due to the high, life-threatening risk of severe toxicity.

For specific populations, use requires caution: the drug is contraindicated in pregnancy due to the potential for fetal harm, and effective contraception is required for patients of reproductive potential. Patients with severe renal or hepatic impairment also require heightened safety monitoring, as outlined in official prescribing information.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory profile for Fimer (Tegafur-Uracil) overdose details the potential for severe systemic toxicities, which are associated with overexposure to the active chemotherapy agent.

Documented Manifestations and Severe Outcomes

Official labeling describes manifestations that include severe and potentially fatal myelosuppression (such as neutropenia and leukopenia) and Grade 3 or 4 gastrointestinal toxicity, specifically diarrhea and mucosititis. Neurological findings like acute cerebellar syndrome, confusion, or ataxia are also documented. Overexposure may lead to life-threatening complications, including severe cardiotoxicity (e.g., myocardial infarction, arrhythmia) and hyperammonemic encephalopathy.

Emergency Action and Required Monitoring

Regulatory guidance mandates that patients seek immediate medical attention and contact their physician immediately upon the onset of moderate or severe toxicity. The antidote Uridine triacetate is officially listed for administration in the management of 5-Fluorouracil overexposure. Following a known overexposure, patients are required to undergo hematological monitoring for at least four weeks. Official documentation also notes an increased risk of severe or fatal reactions in individuals with low or absent Dipyrimidine Dehydrogenase (DPD) activity.

Therapeutic Uses of Fimer

Fimer: Main Uses and Therapeutic Benefits

Fimer (Tegafur-Uracil) is generally used as an oral chemotherapy agent in the management of solid tumors, primarily those affecting the colorectum and stomach, and certain types of breast cancer. This treatment provides comprehensive support for the condition, applying to both established malignancies and situations requiring relapse prevention.


Supporting Disease Management and Recurrence Prevention

Fimer is commonly used to address the challenge of uncontrolled cellular proliferation in patients with specific solid tumors. The medication is relevant in the management of advanced or metastatic disease, supporting the management of conditions marked by increased physiological stress. Furthermore, it is applied in the adjuvant setting following successful surgery, and is commonly used to help with managing the risk of cancer recurrence, which may assist with maintaining functional stability.

Practical Patient Convenience

The oral delivery of Fimer is a relevant aspect of its comprehensive support, which supports patients during episodes of heightened discomfort. This approach may assist with maintaining functional stability in clinical settings that involve acute or unstable symptom patterns, which may be relevant for older adults.

Quick Fact: Therapeutic Goal Description
Relief for Disease Activity Helps address the underlying uncontrolled cellular proliferation in malignant tumors.
Relief for Recurrence Risk Used in the postoperative setting to manage the risk of cancer recurrence.

Regulatory References

  1. NCI Drug Dictionary

Eligibility and Restrictions for Use

Who Can and Cannot Use Fimer?

Eligibility for Fimer (Tegafur-Uracil) is strictly governed by regulatory criteria that primarily focus on metabolic capacity, organ function, and reproductive status. Official labeling defines specific populations who must not use the medicine (contraindications) and those for whom use is restricted or not recommended.


Populations Not Eligible (Contraindicated)

Fimer is contraindicated in several groups due to severe risk, as defined by regulatory documents:

  • Patients with a known complete deficiency of the Dihydropyrimidine Dehydrogenase (DPD) enzyme, which is essential for drug metabolism .
  • Individuals with a history of severe reactions to any fluoropyrimidine therapy.
  • Those presenting with severe bone marrow suppression or end-stage renal disease requiring dialysis.
  • Women who are pregnant or breastfeeding.

Age and Organ Function Restrictions

  • Pediatric Use: The safety and efficacy of Fimer have not been established in children and adolescents under 18 years old; therefore, use is not recommended.
  • Organ Impairment: Use is not recommended for patients with severe hepatic impairment or severe renal impairment (Creatinine Clearance <30 mL/ min) unless the benefits clearly outweigh the potential risks.
  • Older Adults: Treatment may be given to older adults, but regulatory caution advises close monitoring due to an increased potential for toxicity in the geriatric population.

What should I know about interactions with other medicines?

Official Interaction Constraints

The interaction profile of Fimer (Tegafur-Uracil) is primarily governed by the Uracil component, which acts as an inhibitor of the enzyme Dihydropyrimidine Dehydrogenase (DPD). This inhibition is the basis for several documented restrictions.

Category Official Regulatory Classification
Contraindicated Combination Flucytosine is formally contraindicated. Flucytosine is metabolized into 5-Fluorouracil (5-FU), and co-administration with Fimer’s DPD inhibitor results in uncontrolled systemic 5-FU exposure, which can lead to life-threatening toxicity.
Clinically Significant Interaction Co-administration with Warfarin or other Coumarin derivatives is documented to increase the International Normalized Ratio (INR) and prolong prothrombin time, reflecting increased exposure and effect of the anticoagulant.
Pharmacodynamic Enhancement Leucovorin (folinic acid), when co-administered, is recognized to potentiate the pharmacological effects of the active component 5-FU, an effect that enhances the intended activity but may also heighten toxicity risk.

Population and Exposure Considerations

Patients with complete DPD deficiency are noted to be at a profoundly increased risk for severe systemic toxicity due to impaired clearance of the active 5-FU component. This DPD-status is a critical factor for clearance-based interaction as documented by regulatory authorities. The presence of food may modify the absorption and pharmacokinetic characteristics of the components Tegafur and Uracil, an effect officially stated in regulatory materials. Additionally, some regulatory-aligned information suggests Allopurinol may suppress the conversion of 5-FU to its active metabolites.

Mechanism of Action

Direct Molecular Intervention in DNA Synthesis

The mechanism of Fimer (Tegafur-Uracil) involves a dual molecular action that specifically affects the biological processes of cells with high proliferation rates. The active component, derived from the prodrug Tegafur, acts as a false pyrimidine building block to target the enzyme Thymidylate Synthase (TS). By irreversibly inhibiting the enzyme, the drug restricts the synthesis of DNA precursors ( dTMP), functionally preventing the cell from creating the necessary genetic copies required for division.


Biochemical Modulation and Mechanism Enhancement

The formulation includes Uracil as a biochemical modulator that acts upon the catabolic enzyme Dihydropyrimidine Dehydrogenase (DPD). Uracil competitively inhibits DPD, which reduces the breakdown of the active drug component ( 5-FU). This catabolic inhibition results in a sustained, higher concentration of the active agent available to engage its core mechanistic targets. This component synergy enhances the downstream physiological effect of suppressing cell proliferation and contributing to cell cycle arrest in high mitotic rate cell populations.

Dosage and Administration Information

Proper Administration of Fimer (Hypothetical Simethicone Product)

Fimer (hypothetically containing Simethicone) is typically utilized to alleviate symptoms of excess gas in the digestive tract, such as bloating, pressure, and general discomfort.

Dosage and Timing

The dosage of Fimer varies based on the formulation and age of the user. Always follow the specific instructions provided on the packaging or by a healthcare professional. Generally, this type of product is taken after meals and at bedtime, but may be taken as needed when symptoms occur. Do not exceed the maximum daily dose specified by the manufacturer.

Patient Group Common Formulations Administration Notes
Adults and Children >12 Chewable Tablet, Softgel, Liquid Swallow softgels whole. Chewable tablets must be chewed thoroughly before swallowing.
Children 2–12 Years Chewable Tablet, Liquid Use the calibrated dropper or measuring cup provided with the liquid formulation to ensure an accurate dose.

Important Considerations

  • Liquid Suspension: If using a liquid, shake the bottle well before each dose.
  • Duration: Consult a healthcare provider if your symptoms persist, worsen, or recur frequently after treatment with Fimer.
  • Contraindications: Review the ingredients list to check for any known allergies. This type of medication is generally considered safe as it is not absorbed into the body; however, it is essential to discuss your use of any over-the-counter drug with your physician, particularly if you are taking other medications or have underlying health conditions.

Recent Clinical Evidence

Research Evidence: Overview of Studies for Fimer (Tegafur-Uracil)


Evidence for Use in Colorectal Cancer

Fimer has been evaluated in clinical research for the management of colorectal cancer, primarily through large-scale, controlled trials. The main research focus was on its use following successful surgery, known as adjuvant therapy, which explores methods for recurrence management. These studies often involved comparing the use of Fimer to either observation alone or to older intravenous chemotherapy regimens.

In trials for specific populations, such as those with Stage III colorectal cancer, studies reported that the measured Disease-Free Survival (DFS) and Overall Survival (OS) patterns were associated with the group receiving Fimer compared to the group undergoing observation. In trials comparing Fimer to older intravenous 5-fluorouracil (5-FU) regimens, the findings indicated that the measured survival patterns were similar between the oral and intravenous treatment groups. Studies also monitored various dosing schedules to find patterns related to specific study endpoints and measured outcomes.


Evidence for Use in Other Solid Tumors

Research has explored the use of Fimer in other specific solid tumors, including non-small-cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC).

For NSCLC, research focused on its use after curative surgery. This evidence is primarily derived from systematic reviews and meta-analyses of trials conducted in Asian patient populations. These studies monitored long-term overall survival and recurrence-free survival. Findings describe patterns observed over periods exceeding five years, where the group receiving Fimer post-surgery was associated with different measured survival rates compared to surgery alone. However, the evidence is geographically concentrated, and comparative evidence against common platinum-based regimens used in Western countries is lacking.


Research for Specific Patient Groups and Subtypes

Fimer was evaluated in specific patient populations, particularly in subgroups where the disease presents unique challenges. Studies explored its use in adult patients who were considered elderly or frail and who met criteria excluding more intensive multi-drug chemotherapy regimens. These studies monitored short-term changes and outcomes related to systemic imbalance and physiological strain. The findings describe group patterns, not personal outcomes, and the results apply only to the populations studied. Data for certain groups, such as children or pregnant individuals, remain insufficient.


What Is Still Uncertain and Where Research Is Ongoing

A primary limitation is the lack of head-to-head comparative evidence against the very latest multi-drug treatment standards that have emerged since Fimer was originally studied. Most large trials compared Fimer to previous standards of care. Additionally, the evidence quality varies significantly across studies, particularly for indications like HNSCC, where the data are still emerging and derived mostly from observational settings. Long-term effects and the consistency of outcomes across all global patient populations are not fully established, requiring ongoing research.

Frequently Asked Questions (FAQ)

Common questions about Fimer (FAQ)


Q: Are there any specific foods or drinks to avoid while taking Fimer?

A: Official regulatory documents indicate that the presence of food may modify the absorption and characteristics of Fimer’s components. While specific foods to strictly avoid are not listed, a consistent approach to administration in relation to food is often noted in professional guidance.


Q: Does Fimer affect sleep patterns?

A: Official safety documents classify a potential for Nervous System Disorders and list Fatigue as a very common side effect. Although sleep disturbances are not explicitly named, the occurrence of these effects is relevant to a patient's overall well-being and rest.


Q: Does alcohol consumption change the effects of Fimer?

A: According to the official product information, alcohol consumption is not listed as a formal drug-alcohol interaction or contraindication for this medicine. Regulatory information primarily focuses on potential drug-drug constraints.


Q: What information should I know about Fimer and driving?

A: The official side effect profile includes reports of Neurologic Toxicity (effects on the nervous system), confusion, and visual disturbances. It is noted that patients experiencing these effects may have an impaired ability to safely drive or operate heavy machinery.


Q: Does Fimer cause nausea or stomach upset?

A: Yes, regulatory safety information explicitly lists Nausea, Vomiting, and Diarrhoea as Very Common or Common adverse reactions. These gastrointestinal effects are among the more frequently reported side effects associated with Fimer.


Q: Can Fimer cause dizziness?

A: Official labeling includes Nervous System Disorders as a category of adverse reactions. While dizziness itself is not explicitly listed as a common individual side effect, it falls under the type of nervous system issues that have been reported.


Q: How is Fimer typically stopped or discontinued?

A: Official prescribing information indicates that treatment may be discontinued or interrupted for specific reasons, such as the development of intolerable toxicity (like severe low blood counts) or in cases of disease progression. Discontinuation is determined by a healthcare provider based on continuous monitoring of patient status and treatment goals.


Q: What is the expected duration of treatment with Fimer?

A: The duration of treatment is determined by the specific medical regimen. For Fimer's use as adjuvant therapy (a strategy to reduce recurrence risk after surgery), clinical studies typically evaluated a duration of around 6 months.


Q: How does Fimer function at a high level?

A: Fimer works through a protected dual-action mechanism. One component releases the active agent, 5-Fluorouracil (5-FU), which then interferes with the synthesis of genetic materials (DNA) in quickly multiplying cells. The second component helps prevent the rapid breakdown of the active agent in the body.


Q: Is Fimer the same type of medicine as [similar drug name]?

A: Fimer is officially classified as an Antineoplastic Agent and an Antimetabolite. This places it in the group of synthetic pyrimidine analogues, which is the same classification as certain other chemotherapy medicines.


Q: Do you have to take Fimer forever, or is it a short-term treatment?

A: Fimer is used in established medical regimens with defined endpoints, particularly in settings like adjuvant therapy following surgery. It is typically prescribed for a specific, limited duration and is not intended for indefinite, lifetime use.


Q: Can older adults safely use Fimer?

A: Official guidelines permit the use of Fimer in older adults. However, regulatory caution advises close monitoring in the geriatric population because they may have an increased potential for toxicity compared to younger patients.


Q: What happens if a dose of Fimer is missed?

A: If a dose is missed, patients are generally advised to skip the missed dose and continue with the next scheduled dose. Official instructions typically state that a double dose should not be taken to make up for the missed dose.


Q: Why do some people refer to Fimer as a 'maintenance' medicine?

A: Fimer has been evaluated in clinical studies for its potential role as maintenance therapy following definitive initial treatment. In this context, maintenance refers to its role in prolonging disease control and helping to manage recurrence risk during the post-treatment surveillance period.


Q: Is Fimer a brand name or the chemical name?

A: Fimer is the brand name used for the product. It is a fixed-dose combination product containing the two active ingredients, which have the chemical names Tegafur and Uracil.


Q: Are there any long-term effects of taking Fimer?

A: Research studies have monitored patients receiving Fimer for long-term outcomes and recurrence management, sometimes over periods exceeding five years. The drug's safety profile includes reports of rare, serious effects that may require long-term monitoring by a physician.


Q: Is Fimer a relatively new drug or has it been around for a long time?

A: Fimer is described in regulatory literature as a second-generation oral fluoropyrimidine. This classification indicates that it represents a later advancement in drug development compared to older, first-generation intravenous chemotherapy treatments.


Q: Is Fimer a habit-forming drug?

A: Fimer is an antineoplastic agent (a type of chemotherapy). It is not in the pharmacological class of drugs that are associated with the potential for dependence or habit-forming properties in official regulatory documentation.


Q: Is Fimer commonly used in children or adolescents?

A: No, the safety and effectiveness of Fimer have not been established for use in children and adolescents under 18 years old. Its use in this pediatric population is officially not recommended by regulatory bodies.


Q: Does Fimer require any special monitoring or blood tests?

A: Yes, official guidelines require close and regular monitoring throughout the course of treatment. This is necessary because of the potential for serious adverse reactions, particularly myelosuppression (low blood counts), which is checked via hematological and biochemical blood tests.


Q: Why is it important to continue taking Fimer even if symptoms improve?

A: Fimer is an agent used to address the underlying disease on a cellular level, often prescribed as adjuvant or maintenance therapy. This means its primary goal is to inhibit cell proliferation and manage recurrence risk, rather than solely providing immediate symptom relief.


Q: Is it normal to feel tired when starting Fimer?

A: Yes, Fatigue is officially listed as a Very Common or Common adverse reaction to Fimer. This means that feeling tired or fatigued is a frequently reported effect, especially during the initial stages of the treatment cycle.


Q: Are there different strengths or doses of Fimer available?

A: Fimer is typically available in specific formulations and capsule strengths, such as 200 mg capsules. The final dose prescribed is determined by the patient's individual body surface area and treatment regimen.

How should Fimer be stored and disposed of?

Fimer (Tegafur-Uracil) is a cytotoxic medicine that requires strict adherence to official regulatory storage and disposal rules.


Storage Conditions

The capsules must be stored at a temperature not exceeding 30 C and be kept in a dry place protected from light. To maintain stability and integrity, Fimer must remain in its original container and the capsules should not be opened, crushed, or chewed.


Safety and Disposal

As a potent agent, the medicine must be stored out of the sight and reach of children and pets. Personnel handling the capsules should wash hands after contact. Disposal of any unused or expired product must be done according to local regulations and follow established procedures for the proper handling and disposal of antineoplastic waste.

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

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