Trexan

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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 Trexan

Property Description
Active ingredient Methotrexate (MTX)
Form Oral tablet, Injectable solution
Pharmacological class Disease-Modifying Anti-Rheumatic Drug (DMARD), Immunosuppressant
General Purpose Modifying chronic inflammatory disease course
Origin Synthetic, Folic acid antagonist

What is Trexan and Its Active Ingredient?

Trexan is the trade name for a prescription-only medicine whose active substance is Methotrexate (MTX), a synthetic compound classified as a powerful Disease-Modifying Anti-Rheumatic Drug (DMARD). The active ingredient, Methotrexate, is chemically categorized as an Antimetabolite and is widely recognized for its potent Immunosuppressant properties. Methotrexate is designated as a cytotoxic antimetabolite. This widely held consensus means the medicine works by targeting and slowing down fast-growing cells in the body.

Methotrexate is structurally defined as a Folic acid antagonist, a type of compound that interferes with the body's utilization of folic acid. This established mechanism of action supports its role as a cornerstone of systemic treatment for chronic inflammatory conditions. Methotrexate is the conventional DMARD used in the management of autoimmune diseases. This robust clinical recognition indicates that the medication is a standard foundation for controlling the underlying cause of long-term inflammatory conditions.

Trexan's Composition, Form, and General Purpose

Trexan is a single active ingredient product consisting of only Methotrexate and the necessary non-active excipients required for its final preparation. It is commonly supplied in two primary dosage forms: the oral tablet and a sterile injectable solution. The availability of both the oral and parenteral (injection) routes of administration ensures flexible and efficient delivery for this systemic treatment.

Methotrexate works by exerting an anti-inflammatory action and functioning as an immunosuppressant, which means it helps to calm the body's overactive immune responses that are responsible for chronic inflammation. The general therapeutic goal of Trexan is to modify the course of the inflammatory disease, thereby helping to reduce the progression of associated tissue damage in a way that is clinically recognized as disease-modifying, not merely symptomatic.

Regulatory References

  1. U.S. National Library of Medicine (MedlinePlus)

What side effects are possible with Trexan?

Possible Side Effects and Safety Information

Trexan (Methotrexate) is associated with a range of possible adverse reactions, which are formally classified by frequency and grouped by the System-Organ Class affected, according to official regulatory documentation.

Adverse reactions that are frequently documented (very common or common in official SmPC/FDA labeling) include stomatitis (sore mouth), nausea, abdominal distress, and elevated transaminases (liver enzymes). Other common effects involve the blood system, such as leukopenia (low white blood cell count), and dermatological effects like alopecia (hair loss).


Serious Safety Concerns

Regulatory documents highlight the risk of severe, potentially fatal toxicities. These include profound bone marrow suppression, interstitial pneumonitis (a serious lung disease), and significant hepatotoxicity, which can progress to hepatic fibrosis and cirrhosis. The risk of fatal infections and severe dermatological reactions, such as Stevens-Johnson syndrome, are also explicitly documented safety concerns. Certain toxicities, such as liver fibrosis, are generally associated with prolonged use, while others, like pulmonary symptoms, may occur acutely at any time during therapy.


Population-Specific Safety Constraints

The medicine is officially contraindicated in pregnancy for non-oncological uses due to a documented risk of embryo-fetal toxicity. Safety statements also note that individuals with significant renal or hepatic impairment are at an increased risk of toxicity, requiring particular caution. Furthermore, the label notes the potential for fertility impairment in both male and female patients.

Overdose and Emergency Response

Methotrexate overdose is officially defined by its severe cytotoxic effects and the risk of delayed systemic elimination. Regulatory documents state that overdosage is associated with potentially fatal bone marrow suppression (e.g., Pancytopenia, Leukopenia, Thrombocytopenia) and gastrointestinal toxicity, including severe Ulcerative Stomatitis and Hemorrhagic Enteritis. The highest-risk overdose scenario explicitly reported by regulators is fatal toxicity resulting from the accidental daily administration of the intended weekly dose.

Urgent Action Required

Seek immediate medical attention for any suspected overdose. Official labeling mandates that therapy must be interrupted immediately upon the appearance of severe GI manifestations (such as diarrhea or ulcerative stomatitis) to avert life-threatening complications like intestinal perforation.

Antidote and Management

The primary rescue protocol documented is the prompt administration of the specific antidote, Leucovorin Calcium (folinic acid). Supportive procedures described in official labeling include urinary alkalinization and adequate hydration to promote drug clearance. Continuous monitoring of serum methotrexate levels and blood counts is required throughout toxicity management. Patients with existing renal impairment or third-space fluid accumulation (e.g., ascites) are noted to have an increased risk of toxicity due to compromised drug elimination.

Therapeutic Uses of Trexan

What Trexan Treats: Main Uses and Benefits

Trexan (Methotrexate) is used across therapeutic domains involving symptoms related to systemic imbalance or heightened physiological activity. The primary objective of therapy involves long-term management, focusing on disease course stabilization. The medication is utilized across multiple therapeutic areas, most commonly in rheumatology and oncology.


Key Therapeutic Applications

This medication is generally used as a foundational therapy for systemic, inflammatory conditions like Rheumatoid Arthritis (RA), Psoriatic Arthritis (PsA), and Polyarticular Juvenile Idiopathic Arthritis (pJIA). It is applied in addressing the persistent, disruptive symptoms that interfere with daily functioning, including chronic joint swelling, tenderness, and severe morning stiffness. The core therapeutic benefit contributes to the stabilization of the underlying autoimmune disease, which assists with maintaining functional stability.

Trexan is considered relevant for patients with severe, extensive Psoriasis that requires systemic intervention, and is commonly used in the treatment of various oncological diseases, including specific leukemias and lymphomas, where its benefit contributes to managing the malignant disease manifestations.

“This systemic therapy may assist with managing the course of chronic disease, supporting the patient during difficult episodes by easing distress.”

Quick Fact: Relief for Joint Symptoms The therapy is considered relevant for easing the overall symptom burden in chronic inflammatory arthritis, specifically for easing symptoms related to physical discomfort and the prolonged morning stiffness that interferes with daily functioning.

Eligibility and Restrictions for Use

The official eligibility profile for Trexan (Methotrexate) is strictly defined by regulatory authorities based on age, organ function, and pre-existing medical conditions.

Populations for Whom Use is Allowed

Use is approved for adults with labeled indications like Rheumatoid Arthritis or Psoriatic Arthritis, and for pediatric patients specifically with Polyarticular Juvenile Idiopathic Arthritis (pJIA).

Populations for Whom Use is Contraindicated

Trexan is absolutely contraindicated in patients with a history of severe hypersensitivity to the drug, or who are pregnant or breastfeeding due to teratogenic risk. Use is also prohibited in patients with severe hepatic impairment (severe liver disease), severe renal impairment (severe kidney dysfunction), alcoholism, active peptic ulcer disease, active infectious disease, or pre-existing severe blood disorders.

Restricted and Age-Related Use

Conditional use is necessary for patients with mild to moderate renal or hepatic impairment, often requiring close monitoring. While use is approved for adults, it should be approached with caution in older adults due to potential reduced organ function. Use in pediatric groups outside of pJIA is generally not recommended or not established.

What should I know about interactions with other medicines?

The official regulatory profile for Trexan (Methotrexate) specifies several critical interactions that may modify drug exposure or increase the risk of toxicity. These statements are derived from authoritative government documents.

Contraindicated Combinations

Co-administration with Live Vaccines is explicitly prohibited due to the risk of disseminated infection in immunosuppressed patients. The concurrent use of other Antifolates (e.g., Co-trimoxazole) is also prohibited due to the potential for severe additive toxicity.

Interactions Affecting Drug Exposure

Several medications are documented to reduce Methotrexate clearance, which increases its concentration in the plasma and raises the risk of toxicity:

  • Nonsteroidal Anti-inflammatory Drugs (NSAIDs) and Salicylates reduce the renal elimination of Methotrexate via competitive inhibition.
  • Proton Pump Inhibitors (PPIs) (e.g., Omeprazole, Lansoprazole) can increase Methotrexate plasma concentrations, particularly when Methotrexate is used at higher doses.
  • Certain Penicillins and Antiseizure Medicines (e.g., Phenytoin, Levetiracetam) are also noted to reduce Methotrexate clearance.

Additive Toxicity and Other Products

  • Alcohol (Ethanol) should be strictly avoided or limited, as its concurrent use potentiates the risk of liver toxicity, which is a known effect of Methotrexate.
  • Co-administration with other Hepatotoxic Drugs (e.g., Isotretinoin) or Haematotoxic Medicinal Products also increases the risk of combined organ or blood system damage.
  • Administration of Radiotherapy alongside Methotrexate is documented to increase the risk of soft tissue necrosis and osteonecrosis.
  • The use of Folic Acid/Folinic Acid may reduce the effectiveness of Methotrexate in certain therapeutic contexts.

Mechanism of Action

Blocking the Folate Pathway and Cellular Replication

This mechanism focuses on MTX's role as a structural analog of folic acid and its direct inhibitory effect on the enzyme dihydrofolate reductase (DHFR). By acting as a competitive inhibitor, the drug blocks the synthesis of essential purine and pyrimidine nucleotides, which are the building blocks of DNA and RNA. The resulting systemic effect is the cytostatic slowing of cell division, which affects the proliferation of highly activated cell populations, including lymphocytes.


Enhancing Endogenous Anti-inflammatory Signaling

This distinct, low-dose mechanism targets the inflammation process via an endogenous mediator, adenosine. MTX is converted intracellularly into polyglutamates that inhibit the enzyme AICART, leading to the accumulation and release of high levels of adenosine outside the cell. This adenosine acts as an agonist on A2a and A3 receptors on immune cells, which modulates the release of pro-inflammatory cytokines and affects the adherence of immune cells, resulting in an immunosuppressive physiological state.

Dosage and Administration Information

How Trexan is Used: Administration Guidelines

Trexan (methotrexate) is administered via various routes and strictly controlled schedules. The specific dosing and frequency differ significantly between its use for chronic inflammatory diseases and oncological conditions.

Available Routes and Dosage Forms

Methotrexate is available in multiple forms to allow for flexible systemic treatment. Routes of administration include Oral (tablet or solution), Subcutaneous (SC), Intramuscular (IM), and Intravenous (IV) injection. The Intrathecal (IT) route is also used for specific oncological indications, strictly requiring a preservative-free formulation.


Standard Dosing and Frequency

For chronic inflammatory conditions, Trexan is taken only once weekly. This strict 7-day frequency is critical, and the prescribing physician specifies the exact day of the week for intake.

Indication Standard Starting Dose (Adult) Maximum Weekly Dose (Adult)
Rheumatoid Arthritis (RA) 7.5 mg once weekly (Oral, IM, or SC) 20 to 25 mg once weekly
Psoriasis (Severe) 10 mg to 25 mg once weekly Up to 30 mg per week

Administration Requirements and Adjustments

Treatment begins with a low starting dose which is gradually adjusted by the physician until the lowest effective maintenance dose is reached. Oral tablets can be taken with or without food. For pediatric patients with Polyarticular Juvenile Idiopathic Arthritis (pJIA), the dose is typically calculated based on body surface area, at 10 mg/m^2 once weekly. Caution and dose reduction are relevant for older adults and those with renal or hepatic impairment.

Recent Clinical Evidence

Research evidence / Overview of studies for Trexan (Methotrexate)

Evidence for Use in Rheumatoid Arthritis (RA)

Research has extensively explored Trexan in the context of Rheumatoid Arthritis (RA), a condition marked by functional limitations and periods of heightened symptom activity. Studies have involved numerous large-scale Randomized Controlled Trials (RCTs), systematic reviews, and meta-analyses. Researchers examined outcomes related to physical discomfort, such as measuring changes in disease activity scores and counting joint changes. Trials also focused on patient-reported outcomes describing perceived discomfort and functional ability.

Findings describe patterns observed in these studies, reporting changes measured in the core disease activity endpoints and joint counts across the study duration. Long-term observational data also show patterns related to the duration of treatment and observed follow-up. However, what remains unclear is why some study participants did not register a measurable change; the underlying physiological reasons for this variability in reported outcomes are not fully established. The evidence highlights what is known, but the results reflect specific group patterns and do not determine whether an individual will respond similarly.


Evidence for Use in Psoriatic Arthritis (PsA)

Trexan was evaluated in studies for Psoriatic Arthritis (PsA), a condition characterized by fluctuating manifestations affecting both the joints and the skin. The research includes a combination of Randomized Controlled Trials (RCTs) and observational settings. Trials measured numeric changes in specialized criteria for PsA, peripheral joint counts, and the severity of the skin component. Findings were mixed or showed considerable variability across studies concerning the measured outcomes for specific features like inflammation in tendons (enthesitis) and digit swelling (dactylitis).

Evidence is limited in the form of historical, large-scale, modern RCTs dedicated solely to PsA outcomes. The measurement protocol for achieving the greatest reported change across all PsA manifestations is not uniformly established across all research protocols. Research exploring the drug's effect on axial involvement (the spine and pelvis) and the long-term measurement of structural change over time in PsA remains an ongoing area of research.


What Is Still Uncertain About Trexan Research

This concluding section synthesizes the main areas where more research is needed. The evidence quality varies across studies, and findings were mixed in certain areas, such as the full set of symptoms related to PsA. Sample sizes were modest in some trials, meaning results apply only to the populations studied. Research is ongoing to establish more definitive comparative data, and there is limited information for long-term outcomes, especially regarding the sustained, individual response over many years.

Key Studies & References Methotrexate once-weekly for autoimmune diseases: new measures to reduce risk of fatal overdose due to inadvertent daily instead of weekly dosing - EMA/MHRA Safety Alert

Frequently Asked Questions (FAQ)

Common questions about Trexan (FAQ)

Q: Is Trexan a type of opioid or narcotic?

According to official documents, Trexan (methotrexate) is classified as an antimetabolite and an immunosuppressant. These drug classes work by affecting cell growth or suppressing the activity of the immune system. Trexan is not an opioid or a narcotic.

Q: Is there a generic version of Trexan available?

Yes, the medicine is available under its generic name (methotrexate). It is also sold under various brand names, such as Trexall, Otrexup, Rasuvo, Xatmep, and Jylamvo.

Q: How long does it usually take to feel the effects of Trexan?

Studies and official information indicate that for some chronic inflammatory conditions, initial effects may be observed within 6 to 8 weeks of starting treatment. In research, patterns indicate that a full response may require a longer period of time, sometimes extending to 5 or 6 months of continued therapy.

Q: Does using Trexan require regular blood tests?

Yes, regulatory documents require close monitoring with regular laboratory tests. These typically include tests for complete blood counts (CBC), renal function (kidney), and liver function tests due to the risk of serious toxic reactions to these organs.

Q: How long does Trexan stay in your system after stopping it?

Official pharmacokinetic data estimates that for the low-dose use prescribed for inflammatory conditions, the majority of the medicine is removed from the system relatively quickly. The time it takes ranges from approximately 16.5 hours to 55 hours.

Q: Is Trexan considered a high-risk medication?

Official product information and regulatory labeling include Boxed Warnings (the highest level of warning) that reference the possibility of serious or life-threatening toxic reactions. Therefore, close monitoring is required for toxicities affecting the bone marrow, liver, lungs, and kidneys.

Q: Can Trexan be used during pregnancy or while breastfeeding?

For non-cancer uses, the medicine is contraindicated in pregnancy due to the documented risk of embryo-fetal toxicity (harm to the fetus). Additionally, official patient information includes constraints against breastfeeding while using the medication.

Q: What are the long-term effects of taking Trexan?

Official documents note that prolonged use is specifically associated with a risk of significant hepatotoxicity, which means liver damage, including the development of hepatic fibrosis and cirrhosis. Due to this risk, patients are closely monitored throughout therapy.

Q: Does Trexan interact with common vitamins or supplements?

Yes, the medicine is known to interact with folic acid and other vitamin preparations that contain it. Official information states the importance of reviewing all vitamins or supplements with a healthcare provider, as some may interfere with how Trexan works or how the body handles it.

Q: Does Trexan interact with birth control pills?

The medicine is generally not known to affect the function of oral contraceptive pills. However, official patient information notes that if severe vomiting or diarrhea occurs, the contraceptive pill's protection may be compromised.

Q: Does Trexan interact with herbal teas?

While specific herbal teas are not listed on regulatory labels, official patient information emphasizes the need to review all substances, including vitamins, supplements, and items from a health food shop, with a healthcare provider.

Q: Are there any specific foods or drinks I should avoid while on Trexan?

Alcohol (ethanol) use is subject to strict avoidance or limitation due to the potential for increased liver toxicity, as noted in regulatory documents. Oral tablets may otherwise be taken with or without food.

Q: Can older adults use Trexan safely?

Official labeling requires caution and possible dose reduction for older adults, often starting with a lower dose due to factors like reduced renal (kidney) function, which can affect how the body eliminates the medicine.

Q: Can Trexan be used by people who have liver problems?

Individuals with significant hepatic (liver) impairment are at an increased risk of toxicity because the liver helps process the drug. For these patients, especially careful monitoring, dose reduction, or discontinuation of the medicine may be required.

Q: Is Trexan safe for people with kidney disease?

Individuals with significant renal (kidney) impairment are at an increased risk of toxicity because the kidneys help eliminate the medicine from the body. Close monitoring, dose reduction, or discontinuation of the medicine may be required, as elimination is reduced.

Q: Can Trexan make me feel dizzy or tired?

Official patient information lists dizziness and fatigue or drowsiness as potential side effects.

Q: Can I drive or operate machinery while using Trexan?

Because the medicine may cause dizziness or tiredness, official information includes a warning that patients should refrain from driving or operating machinery until they are certain how the medicine affects their alertness and functional abilities.

Q: Can Trexan cause mood changes or emotional side effects?

Adverse events related to the central nervous system have been noted in official reports. These events, which in case reports have included symptoms like mood alteration or other cranial sensations, require careful monitoring.

Q: Does Trexan affect dental health or gums?

The official adverse reaction lists note that ulcerative stomatitis (sore or inflamed mouth) is a common side effect. Bleeding gums have also been reported, and caution regarding dental hygiene is mentioned in patient information.

Q: Is it normal for my urine to change color when taking Trexan?

A noticeable change in how much or how often urine is passed, or the appearance of dark urine, is noted in adverse event listings as a symptom that could indicate a serious underlying kidney or liver problem. Such changes are documented as requiring immediate medical review.

Q: What should I do if I experience a skin rash while taking Trexan?

Official documents document a risk of severe dermatological reactions, such as Stevens-Johnson syndrome. If blistering, peeling, or loosening of the skin is observed, official patient guides indicate that an immediate medical review is necessary.

Q: Can I stop taking Trexan suddenly if I feel better?

Regulatory patient guides describe the constraint that the dose must only be modified or discontinued with the explicit guidance and supervision of a physician.

Q: What should I do if the side effects of Trexan are bothering me?

Official patient guidance indicates that many side effects can be managed by lowering the dose or discontinuing the drug. Any change in dose or discontinuation is conditioned upon a doctor's supervision. Severe symptoms, such as difficulty breathing, are documented as requiring immediate medical review.

Q: Is Trexan safe for people who have heart conditions?

While the medicine does not list specific heart conditions as a contraindication, research evidence suggests that for people with rheumatoid arthritis, methotrexate use is associated with a reduction in overall cardiovascular disease risk.

Q: Is the research evidence for Trexan strong?

Research includes extensive randomized controlled trials (RCTs) and systematic reviews exploring its use in inflammatory diseases. While some studies provide strong evidence of benefit in key areas, official summaries note that others show variability or mixed findings, and long-term safety data remains limited.

Q: What is the expected outcome if I use Trexan as described by my doctor?

Studies have examined measured changes in core disease activity endpoints and joint counts over time. For example, some research has indicated that patients receiving methotrexate for rheumatoid arthritis were significantly less likely to suffer fatal cardiovascular events compared to those not receiving the medicine.

How should Trexan be stored and disposed of?

Trexan (methotrexate) tablets must be stored according to official regulatory specifications to maintain product integrity and safety.

Storage & Disposal Scope Official Requirement
Labeled Storage Temperature Controlled Room Temperature: 20 C to 25 C (68 F to 77 F), with excursions allowed up to 30 C (86 F).
Protection & Handling Keep in the original, tightly closed container. Do not freeze or refrigerate. Maintain out of the sight and reach of children for mandatory protection.
Disposal Instructions Dispose of unused or expired medicine using an established drug take-back program or by following specific regulatory household disposal guidelines. The product must not be disposed of in wastewater or sewage due to its cytotoxic classification.

These official regulatory requirements strictly define the environmental constraints and handling necessary for the medicine, and mandate safe disposal protocols for this type of hazardous medicinal product.

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

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