Repso

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Repso

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Medically reviewed

Marina Burgos

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 Repso

Quick Facts

Property Description
Active ingredient Leflunomide
Form Film-coated tablets
Pharmacological class Disease-Modifying Antirheumatic Drug (DMARD); Immunosuppressive Agent
Common purpose Long-term control of chronic autoimmune diseases
Origin Synthetic, conventional (non-biologic)

What Type of Medicine is Repso?

Repso is a synthetic, oral medicine containing the active ingredient Leflunomide. It is classified as a conventional Disease-Modifying Antirheumatic Drug (DMARD), which also functions as an immunosuppressive agent. This classification distinguishes it from simple pain relievers, confirming its role is to actively modify the underlying course of chronic inflammatory diseases. Leflunomide is an immunosuppressant indicated for rheumatoid arthritis and psoriatic arthritis. This agent slows the progression of joint damage associated with these conditions, supporting its use in long-term treatment plans. As a single-ingredient product, Repso is supplied in the form of film-coated tablets for oral administration, delivering systemic therapeutic effects.


Repso's Purpose and Composition

The primary purpose of Repso is the long-term management and control of underlying disease activity in chronic autoimmune conditions. The core component is the active chemical compound Leflunomide. This substance is a prodrug, meaning it must first be metabolized in the body into its active form, teriflunomide. Leflunomide works by inhibiting the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH). This action limits the growth of immune cells responsible for inflammation. This specific mechanism results in the desired immunosuppressive effect, helping to control inflammation and suppress the aggressive activity of the immune system over the long term, offering a method to sustain disease remission.

Regulatory References

  1. European Medicines Agency

What side effects are possible with Repso?

Possible Side Effects and Safety Information

This information describes the documented safety profile of Repso, based strictly on official government regulatory documents. It outlines the types of adverse reactions, critical safety warnings, and required monitoring.

Frequency-Classified Adverse Reactions

Clinical trial data categorizes adverse reactions based on their frequency of occurrence, often grouped by System Organ Class (SOC) as defined by regulatory standards (e.g., MedDRA). Reactions are typically listed as very common, common, uncommon, or rare.

  • Common Adverse Reactions: Events reported frequently in clinical trials may include symptoms such as fatigue, dizziness, gastrointestinal disturbances (e.g., constipation), and certain nervous system effects. The reporting rates are used to communicate the expected risk profile.

Serious and Clinically Significant Risks

Official regulatory information highlights serious or clinically significant adverse reactions that warrant specific attention and monitoring. These are reactions that may be life-threatening, result in hospitalization, or cause significant disability. They require defined management plans, including potential dose modifications.

  • Key Warnings and Precautions: Official labeling mandates monitoring for critical risks such as Interstitial Lung Disease (ILD)/Pneumonitis, severe Hepatotoxicity (liver damage), and certain adverse effects on the Central Nervous System (CNS).
  • Dose Modifications: Regulatory documents specify that Repso should be withheld or permanently discontinued if specific severe adverse reactions reach defined severity grades, particularly for confirmed ILD/Pneumonitis or recurrent high-grade hepatotoxicity.

Population-Specific Safety Considerations

Specific safety requirements are documented for certain populations:

  • Embryo-Fetal Toxicity: Repso carries a risk of harm to the fetus. Females of reproductive potential are required to use non-hormonal contraception during treatment and for a specific period after the last dose.
  • Lactation: It is advised that women should not breastfeed during treatment due to potential risk of adverse reactions in the breastfed child.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory description of a Repso (Leflunomide) overdose focuses on specific clinical signs and the management of severe systemic toxicity. The primary concern is the potential for severe liver injury (hepatotoxicity), including the risk of fatal liver failure, which is highlighted in official warnings. Risk is heightened for patients with pre-existing liver disease or those taking other hepatotoxic drugs.

Overdose presentations documented in regulatory labeling may include symptoms such as diarrhea, stomach pain, extreme tiredness, pale skin, fast heartbeat (tachycardia), and shortness of breath.

Immediate Actions Mandated by Regulators
Call emergency services (e.g., 911) immediately if signs of life-threatening toxicity occur, such as collapse, seizure, or severe trouble breathing (respiratory distress).
Call poison control immediately for any suspected overdose event.

There is no specific antidote known for Repso. Management of overdose or severe toxicity centers on an accelerated drug elimination procedure, which involves the administration of substances like cholestyramine or activated charcoal to hasten the removal of the active metabolite. Following this intervention, mandatory weekly monitoring of liver function tests is required until enzyme levels have normalized.

Therapeutic Uses of Repso

Therapeutic Indications

Repso is primarily utilized in the management of specific chronic inflammatory conditions. Its active mechanism is designed to modulate the immune response, particularly in cases where the body's natural defenses inadvertently target healthy tissues.

Rheumatoid Arthritis

In the context of rheumatoid arthritis, this medication is used to address systemic inflammation within the joints. It is typically indicated for patients who have experienced an inadequate response to first-line disease-modifying antirheumatic drugs. The primary objectives of treatment in this area include:

  • Reduction of Inflammation: Lowering the activity level of inflammatory markers to decrease joint swelling and tenderness.
  • Prevention of Structural Damage: Helping to slow the progression of joint destruction and bone erosion.
  • Improvement of Physical Function: Enhancing the patient's ability to perform daily activities by maintaining joint mobility.

Psoriatic Arthritis

For individuals with psoriatic arthritis, the treatment addresses both the joint manifestations and the associated skin involvement. By targeting specific pathways in the immune system, it helps manage the multi-faceted nature of this condition.

Plaque Psoriasis

This medication is also used for the treatment of moderate-to-severe plaque psoriasis. It is indicated for patients who are candidates for systemic therapy or phototherapy. The clinical focus is on:

  • Skin Clearance: Reducing the thickness, redness, and scaling of psoriatic plaques.
  • Symptom Management: Alleviating the physical discomfort often associated with extensive skin lesions.

Axial Spondyloarthritis

Repso is employed in cases of axial spondyloarthritis, including ankylosing spondylitis. It focuses on reducing inflammation in the spine and pelvic joints, which is the hallmark of these conditions. Treatment aims to reduce stiffness and maintain spinal flexibility over the long term.

Regulatory References

  1. NIH MedlinePlus information

Eligibility and Restrictions for Use

Repso is strictly authorized for use only in adult patients 18 years of age and older. The official regulatory labeling contains multiple absolute contraindications that prohibit its use in certain populations.

Contraindicated Populations (Must Not Use) Official Eligibility Status
Patients with known Hypersensitivity (severe allergic reaction) to the drug, its active metabolite (teriflunomide), or any excipients. Contraindicated
Pregnant women or women of childbearing potential not using reliable contraception. Contraindicated
Patients with impairment of liver function. Contraindicated
Patients with severe immunodeficiency states (e.g., AIDS) or serious infections. Contraindicated
Patients with significantly impaired bone marrow function or severe anaemia, leucopenia, neutropenia, or thrombocytopenia not caused by their condition. Contraindicated
Patients with moderate to severe renal insufficiency (due to insufficient clinical experience). Contraindicated
Patients with severe hypoproteinaemia (e.g., in nephrotic syndrome). Contraindicated

Age and Usage Restrictions

The drug is not recommended for use in patients below 18 years of age because its safety and efficacy in the pediatric population have not been established. Use is also restricted by pre-existing physiological conditions, as the official documentation explicitly prohibits treatment for patients with certain severe blood, liver, and kidney disorders.

What should I know about interactions with other medicines?

Interactions with Other Medicines and Products

The interaction profile for Repso is officially defined by its active metabolite, teriflunomide, which is the basis for several regulatory constraints. The co-administration of Teriflunomide (a separate pharmaceutical product containing the same metabolite) is formally contraindicated by regulatory bodies, and treatment is also contraindicated in individuals with severe hepatic impairment due to the critical role of liver clearance pathways.

The active metabolite is documented as a modulator of drug disposition: it is an inhibitor of CYP2C8, OAT3, BCRP, and OATP1B1/B3 transporters/enzymes, which may increase the systemic exposure of certain co-administered medicinal products. For example, a mandatory dose restriction applies to Rosuvastatin when co-administered. Conversely, the metabolite acts as an inducer of CYP1A2, potentially reducing the exposure of its substrates, including components of oral contraceptives.

A pharmacodynamic risk also exists: the co-administration of alcohol or other hepatotoxic agents (like Methotrexate) is noted to potentiate the risk of severe liver injury. Due to the metabolite’s long half-life, a mandatory accelerated drug elimination procedure is required upon discontinuation in specific high-risk scenarios, such as prior to pregnancy or switching to other highly hepatotoxic therapies, to reduce the metabolite's concentration below a defined threshold.

Mechanism of Action

The mechanism of Repso (Leflunomide) is centered on modulating the proliferation of rapidly dividing immune cells by inhibiting a crucial metabolic pathway required for cellular multiplication.

Targeted Metabolic Blockade of DHODH

This domain covers the medicine's interaction with its primary biological target, the mitochondrial enzyme Dihydroorotate Dehydrogenase (DHODH). The active metabolite, Teriflunomide, acts as a specific inhibitor of DHODH, which stops a rate-limiting step in the De novo Pyrimidine Synthesis Pathway. This action creates a controlled metabolic deficiency necessary for the next step in the cascade.


Cytostatic Suppression of Lymphocyte Expansion

By blocking pyrimidine synthesis, this mechanism selectively causes highly active T and B lymphocytes to enter G1 cell cycle arrest. Because these specific cells require high levels of pyrimidines to proliferate, the resulting cytostatic effect limits their population size. This functional consequence attenuates the systemic activity of proliferating auto-reactive lymphocytes, contributing to system-level immunomodulation.


Mechanistic Selectivity via Pathway Dependence

The mechanism's selectivity is due to its effect on cells that are heavily reliant on the De novo pathway for multiplication. Resting cells, which primarily use the alternative salvage pathway, are largely unaffected. This ensures that the drug's effect is focused on the proliferating auto-reactive lymphocyte population, limiting the impact on non-proliferating cells.

Dosage and Administration Information

How to Use Repso: Official Administration Guidelines

Repso (leflunomide) is an oral medication prescribed for long-term management of chronic autoimmune conditions. Treatment must be initiated and supervised by specialists experienced in treating the relevant types of arthritis, ensuring proper clinical oversight of the administration protocol.


Standard Dosing Regimens

The approved dosage of Repso involves a structured approach, typically starting with an initial high dose to rapidly achieve therapeutic concentration, followed by a consistent maintenance regimen:

Regimen Phase Dose and Frequency (Adults) Notes
Loading Dose (Optional) 100 mg once daily for 3 days Used to expedite therapeutic levels; may be omitted based on clinical factors.
Maintenance Dose 10 mg or 20 mg once daily The maximum recommended daily dose is 20 mg.

Administration and Timing

Repso is administered as a film-coated tablet that should be swallowed whole with sufficient liquid. The timing of administration is flexible; the medicine may be taken with or without food as the absorption of leflunomide is not significantly affected by meals.

For flexibility in dosing, the 20 mg tablet is scored and may be divided to allow for the 10 mg maintenance dose when prescribed. The duration of use is typically long-term, consistent with its role as a Disease-Modifying Antirheumatic Drug (DMARD); the onset of a full therapeutic effect may take four to six weeks.


Population-Specific Rules

Official labeling addresses use in specific populations. No specific dosage adjustment is required for older adults (age 65 and over) or for patients with mild renal impairment. However, the use of Repso is not recommended for the pediatric population (patients under 18 years old) because the safety and efficacy of the drug have not been sufficiently established in this age group.

Recent Clinical Evidence

Research Evidence Overview of Studies for Repso (Leflunomide)

Research Evidence for Active Rheumatoid Arthritis (RA)

Repso was studied for the long-term management of active rheumatoid arthritis (RA) primarily through numerous large Randomized Controlled Trials (RCTs). These short- and intermediate-term trials included adult participants and examined outcomes related to physical discomfort and disease activity (like the ACR criteria). Researchers also examined outcomes reflecting daily functioning or activity level and monitored for changes in the radiographic evidence of joint damage. Studies reported measurements using standardized scales over periods typically ranging from six months to two years, comparing observed patterns to those seen in a placebo group. Long-term effects are not fully established by controlled trials, relying mainly on observational settings.

Research Evidence for Active Psoriatic Arthritis (PsA)

Evidence for Repso's use in active psoriatic arthritis (PsA) was evaluated in a pivotal, multinational, controlled trial. This study enrolled adult participants and examined outcomes linked to inflammatory or irritative states using specific response criteria (PsARC) and measures of skin involvement (PASI scores). Studies explored how symptoms evolved over a short-term duration, typically around six months. The core study data are derived from studies with limited follow-up duration, and data for certain subgroups remain insufficient compared to the evidence base for RA.

Evidence Gaps and Long-Term Uncertainty

Long-term outcomes and the consistency of any observed patterns are primarily characterized by less controlled observational cohort studies. Research highlights changes measured during the study period, but long-term effects are not fully established by evidence with the highest level of certainty. Comparative research is limited regarding Repso and newer treatments across all patient subgroups. Findings from RCTs results apply only to the populations studied, meaning the patterns observed in patient groups with complex coexisting health issues remain uncertain.

Frequently Asked Questions (FAQ)

Common questions about Repso (FAQ)

Q: What should I do if I miss a dose of Repso?

Regulatory guidelines state that if a dose is missed, it is usually taken as soon as it is remembered, unless it is near the time of the next scheduled dose, in which case the missed dose is skipped. Doubling doses is not the recommended procedure, according to official patient information.

Q: Can I take Repso if I am already taking over-the-counter pain relievers?

Official information advises caution when taking Repso alongside common over-the-counter pain relievers, specifically those containing acetaminophen. This is because combining these substances may increase the potential risk of developing liver problems. Full disclosure of all medications to your prescribing specialist is necessary to evaluate potential risks.

Q: What are the most commonly reported side effects of Repso?

Clinical trial data lists several common adverse reactions. These include gastrointestinal disturbances like diarrhea and nausea, as well as general symptoms such as headache, rash, and respiratory infection. Abnormal liver enzyme test results are also frequently reported.

Q: Can Repso cause drowsiness or affect my ability to drive?

Adverse reactions such as dizziness and somnolence (drowsiness) have been reported in some patients. The label contains a caution regarding operating machinery or driving until it is known how the medication affects the individual.

Q: Is Repso a type of antibiotic or a steroid?

Repso is classified as a conventional Disease-Modifying Antirheumatic Drug (DMARD), which is also an immunosuppressive agent. Its role is to modify the disease course, and it is chemically neither a steroid nor an antibiotic.

Q: What happens if I suddenly stop taking Repso?

Because the drug's active metabolite stays in the body for a long time, stopping treatment suddenly due to severe side effects or before a planned pregnancy may necessitate a special accelerated elimination procedure, often called a 'washout.' This procedure is required in specific high-risk scenarios to quickly lower the drug concentration.

Q: What types of allergic reactions are possible with Repso?

Severe hypersensitivity reactions are possible and documented in regulatory documents. These include life-threatening reactions such as anaphylaxis, as well as severe skin disorders like Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN).

Q: Is it normal to feel a change in appetite after starting Repso?

Loss of appetite, clinically referred to as anorexia, is noted in the official regulatory documentation as a reported side effect of this medication.

Q: Is it possible for a side effect of Repso to disappear over time?

Patient counseling derived from clinical experience indicates that certain common adverse effects frequently improve over time with continued treatment. For instance, some patients find that diarrhea, a commonly reported side effect, lessens in severity over the duration of use.

Q: Is it important to take Repso at the exact same time every day?

Repso is generally prescribed for once-daily use, and maintaining a consistent schedule helps ensure the active drug concentration in the body remains steady. Taking it at a similar time each day helps maintain the intended therapeutic concentration.

Q: What should be done if I experience a severe stomach upset from Repso?

Severe symptoms necessitate immediate medical evaluation; the label specifies potential discontinuation if severe adverse events occur that may be related to the drug, such as those indicating liver injury. If severe symptoms are confirmed to be drug-related, a drug elimination ('washout') procedure may be initiated.

Q: Is Repso considered a controlled substance?

The medication is classified as a conventional Disease-Modifying Antirheumatic Drug (DMARD). According to regulatory records, Repso is not scheduled or listed under the Controlled Substances Act.

Q: Are there special precautions for older adults taking Repso?

Official posology information states that no specific dose adjustment is required for patients over 65 years of age. However, caution is generally advised for older adults, and rigorous monitoring of safety parameters is documented as required due to the potential for adverse reactions.

Q: How often do people need follow-up appointments when taking Repso?

Regulatory requirements indicate that Liver enzyme levels (ALT) are monitored at least monthly for the first six months of treatment, and every six to eight weeks thereafter. This monitoring dictates the frequency of necessary follow-up appointments.

Q: Can Repso make me more sensitive to the sun?

Regulatory adverse reaction lists include photosensitivity, which means an increased sensitivity or severe reaction to sunlight exposure. Patients are cautioned to take precautions when exposed to UV light.

Q: Why do official documents mention specific populations when describing Repso use?

Specific populations (such as pregnant, pediatric, or liver-impaired patients) are mentioned in official documents to highlight established contraindications and safety risks. This is based on documented gaps in efficacy data or known potential for harm in these groups.

Q: Can Repso affect blood pressure or heart rate?

Official regulatory information indicates that hypertension, or high blood pressure, is one of the commonly reported adverse reactions associated with Repso. Clinical guidelines indicate that patients who have pre-existing heart conditions or develop elevated blood pressure while on treatment undergo ongoing clinical monitoring.

Q: Does Repso interact with common supplements like vitamins or herbal remedies?

The official product label advises caution regarding the co-administration of Repso with any substance known to cause liver damage. This principle applies to certain herbal remedies and supplements. Full disclosure of all supplements to your prescribing specialist is necessary to evaluate potential risks.

Q: Does alcohol consumption change the effect of Repso?

Official warnings state that alcohol is contraindicated or prohibited while using this medication. Combining Repso with alcohol significantly increases the risk of severe liver damage and potential liver failure.

Q: Are there known long-term effects of taking Repso?

Studies and official information indicate that the efficacy and safety profile of Repso are generally maintained over long-term administration. However, the potential for known severe adverse events remains constant, and continuous and rigorous patient monitoring is documented as necessary throughout the course of treatment.

Q: Does Repso interact with birth control pills?

The active metabolite of Repso may affect the levels of certain components in oral contraceptive pills. For this reason, official prescribing information requires effective, reliable non-hormonal contraception for women of childbearing potential during and for a required period after treatment.

Q: What should I tell my doctor before starting Repso?

Official prescribing information highlights several conditions for necessary disclosure before starting Repso treatment. These include pregnancy status or plans, any pre-existing liver disease, severe infections, or a known hypersensitivity (allergic reaction) to the drug itself.

Q: What is the purpose of the boxed warning (if applicable) mentioned for Repso?

The U.S. regulatory Boxed Warning serves to alert prescribers and patients to the most serious potential risks of the drug. These primary risks involve Embryo-Fetal Toxicity, meaning harm to an unborn fetus, and severe Hepatotoxicity, which is serious liver injury or failure.

Q: Why is the mechanism of action of Repso important for its use?

Repso is classified as a disease-modifying antirheumatic drug (DMARD) because its action targets the underlying disease process. The mechanism involves suppressing the proliferation of highly active immune cells (lymphocytes), which is how the drug helps to control chronic inflammation associated with conditions like RA and PsA.

Q: Do studies suggest that Repso is effective in all patients who take it?

Studies and clinical trial results officially apply only to the specific populations that were studied. Regulatory documents indicate that the efficacy and safety patterns observed in patient groups with complex coexisting health issues often remain uncertain.

How should Repso be stored and disposed of?

How to Store and Dispose of Repso

This information is based strictly on official regulatory labeling for the safe handling and disposal of Repso.


Official Storage Requirements

Temperature and Environment: Repso must be stored at controlled room temperature, generally defined as 20 C to 25 C (68 F to 77 F). Do not store the medicine above 30 C. It is mandatory to protect Repso from moisture and direct sunlight.

Handling and Stability: Do not freeze the product. Keep the medicine in its original container, and ensure the container is tightly closed. Any opened multi-dose container must be used within 28 days and then discarded.

Child Safety: Repso must be stored out of the sight and reach of children to prevent accidental ingestion.


Official Disposal Requirements

Disposal Method: Do not dispose of unused or expired Repso by flushing it down the toilet or placing it in household trash. Return the medicine to an authorized drug take-back location or pharmacy. Disposal must comply with local and national regulations for pharmaceutical waste.

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

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