Metoject

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Metoject

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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 Metoject

Quick Facts: Metoject (Methotrexate)

Property Description
Active Ingredient Methotrexate (MTX)
Form Sterile Solution for Injection (Pre-filled syringe/pen)
Pharmacological Class Immunosuppressive Agent, Antimetabolite
General Purpose Control and stabilize chronic systemic inflammation
Origin Synthetic (Folic Acid Analogue)

What Type of Medicine is Metoject (Methotrexate)?

Metoject is a recognized brand of the prescription-only medicine (POM) containing the active ingredient Methotrexate (MTX), which is classified as an immunosuppressive agent and antimetabolite. The medicine is a synthetic compound known as a folic acid analogue or antifolate, structurally similar to the naturally occurring vitamin folic acid. It is categorized as a Disease-Modifying Antirheumatic Drug (DMARD), signifying its role in intervening with the root progression of chronic inflammatory diseases. Methotrexate is frequently used to reduce inflammation in autoimmune conditions. This classification means the medicine directly helps to lower the long-term inflammatory activity in the body.


How is Metoject Supplied and What is its Composition?

Metoject is distinctively supplied as a sterile aqueous solution for injection, often presented in a pre-filled syringe or the Metoject PEN auto-injector device. This preparation consists of the active substance, Methotrexate, as the sole therapeutic ingredient dissolved in a water-based vehicle, making it a single-agent therapy. It is administered via the parenteral route, most often as a subcutaneous injection (under the skin). This pre-filled, injectable format, which is a key distinguishing feature of the Metoject brand, is necessary to ensure reliable absorption and consistent delivery of the medicine into the systemic circulation, which is critical for maintaining stable immunomodulatory effects.


What is the General Purpose of Metoject's Action?

The general therapeutic purpose of Metoject is to control and stabilize chronic systemic inflammation by modulating the activity of an overactive immune system. As an antifolate, its mechanism involves interfering with the cellular pathways that drive persistent inflammation, leading to a powerful anti-inflammatory effect. Methotrexate is recognized as a cornerstone of therapy due to its ability to modulate the immune response. This deep-acting intervention aims to manage and reduce the overall severity of long-term inflammatory states in patients.

Regulatory References

  1. NIH: MedlinePlus Drug Information
  2. EPAR - Nordimet (Methotrexate)

What side effects are possible with Metoject?

Possible Side Effects and Safety Information

Official regulatory documentation organizes the possible adverse reactions of Methotrexate (Metoject) by frequency and the body's System Organ Class (SOC) to provide a comprehensive profile of safety characteristics.

Frequency-Classified Adverse Reactions

Adverse reactions that are frequently observed, classified as Very Common in regulatory documents (ge 1/10 of patients), typically include inflammation of the mouth (stomatitis), nausea, vomiting, diarrhoea, abdominal pain, and elevated liver enzymes (transaminases). Effects that are Common (ge 1/100 to < 1/10) include headache, fatigue, leucopenia (decrease in white blood cells), hair loss (alopecia), and localized reactions at the injection site. Uncommon and rare effects cover a range of reactions, including pulmonary inflammation (pneumonitis), thrombocytopenia, and rash.

Serious Safety Considerations

The most clinically significant adverse reactions, though infrequent, are explicitly documented in official labeling and necessitate close observation. These include severe myelosuppression (depression of bone marrow function), serious hepatotoxicity (liver damage including fibrosis and potential cirrhosis), and pulmonary toxicity (lung problems). The risk of chronic liver toxicity is noted to increase with long-term, cumulative exposure to the medicine.

Population and Organ Function Constraints

The regulatory profile specifies heightened safety considerations for certain patient groups. Methotrexate is contraindicated in cases of pre-existing severe hepatic impairment or severe renal impairment, as its clearance is dependent on these organs. Older adults require careful monitoring due to age-related organ function decline. The official labeling confirms the requirement for routine monitoring of blood counts and liver function to observe for early signs of toxicity.

Overdose and Emergency Response

The Methotrexate overdose profile, as documented in official regulatory sources, centers on the risk of severe, life-threatening toxicity, most commonly caused by the inadvertent daily administration of the intended once-weekly dose. Overdose may present with critical manifestations across multiple systems. Documented presentations include severe bone marrow suppression, leading to conditions like pancytopenia; acute gastrointestinal toxicity, evidenced by ulcerative stomatitis and diarrhea which may become hemorrhagic; and the risk of acute renal failure.

Immediate medical attention is required upon any suspicion of overdose or if early toxicity signs such as persistent diarrhea or mouth sores appear, as these can escalate to fatal complications like intestinal perforation. The regulatory guidance explicitly mandates that patients must immediately notify their doctor if symptoms of toxicity occur. Management protocols strictly define the immediate use of the antidote Leucovorin (folinic acid) for rescue. Furthermore, supportive procedures, such as maintaining urinary alkalinization, are described to prevent drug precipitation in the kidneys, especially since reduced drug elimination in patients with pre-existing renal impairment or fluid accumulation significantly increases the risk of systemic toxicity.

Therapeutic Uses of Metoject

What Metoject Treats: Main Uses and Benefits

Metoject is used in situations involving certain distressing symptoms applied across domains where additional symptomatic support is needed to address severe, long-term inflammation in specific chronic autoimmune domains. It plays a role in managing underlying disease activity to stabilize conditions and ease the overall symptom burden. It is prescribed for conditions where the immune system attacks the body's own tissues.

Key Therapeutic Focus

The medication is commonly used to manage moderate to severe symptoms of conditions involving episodic or fluctuating manifestations like Rheumatoid Arthritis (RA), Polyarticular Juvenile Idiopathic Arthritis (pJIA), and Severe Psoriasis including Psoriatic Arthritis. This therapy is relevant for easing symptoms that become more disruptive during flare-ups, addressing symptoms related to physical discomfort such as articular swelling, stiffness, and disabling skin plaques. It helps address symptoms that interfere with daily functioning.

“Metoject may be part of symptomatic management for conditions characterized by periods of heightened symptoms such as Crohn's Disease, contributing to easing the overall symptom load.”

Quick Fact: Relief for Joint and Skin Symptoms

The intervention may assist with managing the progression of joint damage and is applied in addressing symptoms related to inflammatory or irritative states such as thick, scaling skin plaques. This contributes to easing the overall symptom load and supports general well-being during symptomatic phases, assisting with symptomatic relief that helps patients cope more steadily with symptom fluctuations.

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Metoject's eligibility is strictly defined by regulatory authorities and is categorized by absolute prohibitions and specific use restrictions.

Populations for Whom Use is Contraindicated

The medicine must not be used in women who are pregnant or breast-feeding, nor in patients with severe liver impairment, severe renal impairment (Creatinine Clearance less than 30 ml/min), pre-existing blood dyscrasias, active severe infections, or active gastrointestinal ulcer disease.

Approved and Restricted Groups

Use is approved for adults with rheumatoid arthritis and severe psoriasis, and for pediatric patients (children and adolescents) with polyarticular juvenile idiopathic arthritis. Use is not recommended in children under three years of age due to insufficient safety data. Patients with moderate renal impairment (30-59 ml/min) require a mandated dose reduction. Additionally, both males and females of reproductive potential must use effective contraception during and for a specified period following treatment cessation, as directed by official labeling.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile of Methotrexate is governed by its status as an antifolate and its primary route of clearance through renal transporters. Regulatory documents define several significant constraints on co-administration with other substances.

Documented Interaction Patterns

Interaction Type Interacting Substances/Classes Outcome Description (Regulatory Statement)
Formal Contraindications Acitretin, Live Virus Vaccines Prohibited due to documented risk of additive hepatotoxicity or impaired immune response, respectively.
Increased Exposure Risk NSAIDs, Penicillins, Proton Pump Inhibitors (PPIs) These agents increase Methotrexate plasma concentrations by reducing its renal clearance.
Additive Toxicity Risk Alcohol (Ethanol), Trimethoprim/Sulfamethoxazole Increased risk of liver damage (hepatotoxicity) or heightened antifolate effects, leading to toxicity.

Interaction-Related Constraints

Highly protein-bound drugs, such as certain sulfonamides or phenytoin, may increase the concentration of available Methotrexate in the plasma by displacement. Regulatory information notes that Folic Acid/Folate Supplements must be spaced from the Methotrexate dose to minimize interference with the intended therapeutic action. Furthermore, interaction-related toxicity risk is officially higher in patients with impaired renal function or third-space fluid accumulation due to slower drug elimination.

Mechanism of Action

Metoject's mechanism of action is multifaceted, involving two distinct biological systems that influence systemic inflammatory processes.

Inhibiting Inflammation via the Adenosine Pathway

This mechanism involves the indirect activation of an endogenous anti-inflammatory signal. Methotrexate competitively inhibits the enzyme AICAR transformylase (ATIC) inside the cell, triggering a metabolic cascade that results in the release of measurable amounts of adenosine. This adenosine binds to A2A and A3 receptors on immune cells, suppressing their function and reducing the production of major pro-inflammatory mediators like TNF- alpha and Interleukin-6 (IL-6). This action modulates excessive signaling within the systemic inflammatory cascade.


Controlling Overactive Immune Cell Proliferation

Methotrexate is an antifolate, which means it inhibits the enzyme dihydrofolate reductase (DHFR), required for the synthesis of DNA and RNA building blocks. This action interferes with the rapid multiplication of aggressive T-lymphocytes and other inflammatory cells. By restraining the proliferation rate of these immune cells, this domain reduces the cellular population available for inflammatory activity, leading to modulation of the immune cell activity profile.

Dosage and Administration Information

How to use Metoject — Administration Guidelines

Administration of Metoject is based on guidelines that dictate the route, frequency, and dosage adjustment process for chronic inflammatory conditions.


Administration Scope

Field Instruction/Guideline
Route of administration: The medicine is administered by Subcutaneous (SC) injection, supplied as a sterile solution in a pre-filled syringe or pen device.
Dosing schedule (Adult): Therapy typically begins with a low starting dose of 7.5 mg once weekly. The dose is gradually adjusted by the prescriber, generally falling within the 10 mg to 25 mg weekly maintenance range.
Frequency pattern: Administration must occur once weekly only, never daily.
Age-group administration rules: Dosing for pediatric patients (pJIA) is calculated based on Body Surface Area (BSA). Dose reduction must be considered for older adults and patients with impaired renal function.

Resulting Procedural Structure

Step sequence:

  • The prescriber determines the fixed weekly day for administration to ensure a consistent schedule.
  • The first injection must be performed under direct medical supervision as part of the initial protocol.
  • The dose is continually titrated to achieve the lowest possible effective maintenance dose within established limits, based on patient response.
  • Required concurrent folic acid supplementation must be scheduled for a day different from the Metoject injection day to prevent interference.

Connection to the overall use protocol: The usage protocol establishes a non-daily, fixed weekly schedule via the parenteral route using a specialized pre-filled device. The process requires medical supervision for the initial dose and adheres to a specific dosing range. This structure ensures the medication is delivered according to its specific timing and preparation requirements, which is a critical constraint of the therapy.

Recent Clinical Evidence

Research evidence / Overview of studies for Metoject


Evidence for Use in Rheumatoid Arthritis (RA)

The research base for Metoject in adult Rheumatoid Arthritis is built upon numerous short-term Randomized Controlled Trials (RCTs), as well as extensive Systematic Reviews and Meta-analyses. Studies have primarily examined patient populations composed of adults with active RA, including those who were new to the treatment and those whose condition state was tracked following limited response to prior conventional therapies. Research monitored changes in key measures such as Disease Activity Scores and clinical response criteria, and also explored outcomes related to physical function and changes in outcomes monitoring physiological strain or stress. Observational evidence provides insight into symptom patterns over a period of years, tracking treatment persistence in the observed populations.


Evidence for Use in Psoriatic Disease (Psoriatic Arthritis and Severe Psoriasis)

The evidence for Psoriatic Disease, which involves conditions characterized by fluctuating or episodic manifestations, was evaluated in RCTs and numerous Systematic Reviews. Researchers studied specific outcomes related to two main areas: skin-related outcomes measured by specific clearance scores, and joint-related outcomes measured by standardized response criteria. The volume of controlled trial data differs between the skin condition (Psoriasis) and the joint condition (PsA). Data for certain PsA groups, such as those with axial involvement (inflammation in the spine or pelvis), remain insufficient. Evidence is limited regarding the measure of radiographic progression (changes in joint damage) in controlled trials, and the certainty remains low for certain findings due to variations in study size and methodological approaches across the research base.


Known Research Gaps and Uncertainties

Research has also explored use in Crohn's Disease and Polyarticular Juvenile Idiopathic Arthritis (pJIA). For Crohn's Disease, studies monitored outcomes related to achieving clinical remission and the rate of patients whose corticosteroid use was monitored for change. For pJIA, studies examined children and adolescents, monitoring outcomes using measures such as pediatric response scores. The initial RCTs that contributed to the overall evidence landscape typically had defined, limited follow-up durations, with long-term data primarily from observational cohort studies which are not derived from controlled research designs. In summary, research provides context for treatment patterns but does not determine whether an individual will respond similarly, and long-term effects for certain outcomes are not fully established by the evidence.

Frequently Asked Questions (FAQ)

Common questions about Metoject (FAQ)


Q: Can I drink alcohol while I am using Metoject?

A: Regulatory documents state that alcohol abuse is a formal contraindication for using this medicine. The medicine's official labeling advises against concomitant use with alcohol because there is a documented increased risk of liver toxicity (hepatotoxicity) when these substances are combined.


Q: Are there any specific vitamins or supplements I should avoid when using Metoject?

A: Official guidance emphasizes that folic acid or folinic acid supplements should only be taken as specifically instructed by a healthcare provider. Taking them outside of guidance could interfere with the therapeutic effects of the medicine. Official documentation for the medicine does not typically list specific restrictions for most other common vitamins.


Q: Can Metoject interact with common pain relievers like ibuprofen or naproxen?

A: Yes, this medicine is known to interact with Nonsteroidal Anti-inflammatory Drugs (NSAIDs), which includes common pain relievers like ibuprofen or naproxen. These pain relievers may increase the concentration of the medicine in the blood by reducing how quickly the kidneys can clear it. This interaction may lead to increased plasma concentrations, which raises the risk of severe side effects.


Q: Can Metoject interact with antibiotics?

A: The official interaction profile indicates that certain antibiotics, particularly those with antifolate properties like trimethoprim/sulfamethoxazole, can dangerously increase the risk of toxicity. Other types of antibiotics, such as penicillins, are also noted to require caution when used alongside this medicine.


Q: Can Metoject cause sun sensitivity?

A: Official information mentions that this medicine may make your skin more sensitive to sunlight, a condition known as photosensitivity. Patients are advised to use sun protection, such as wearing sunscreen, eye protection, and a hat, or avoiding sunlamps and tanning beds.


Q: Can Metoject cause problems with my liver long-term?

A: Liver toxicity, which can include conditions like fibrosis and cirrhosis, is a documented risk associated with long-term use of this medicine. The risk of these problems is noted to increase with the cumulative exposure over time. For this reason, mandatory, close monitoring of liver function is required for all patients.


Q: Can Metoject cause fatigue or tiredness?

A: Yes, fatigue and tiredness are listed in regulatory documents as a common side effect of this medicine. Common means this effect is experienced by ge 1/100 to < 1/10 (1% to 10%) of patients.


Q: Do people who take Metoject need special blood tests?

A: Yes, the regulatory profile confirms the requirement for mandatory, close monitoring during treatment. This monitoring includes routine testing of complete blood counts as well as liver and kidney function to help observe for early signs of toxicity.


Q: Why do some people need to take folic acid with Metoject?

A: Folic acid or folinic acid is often prescribed for use alongside this medicine to reduce the chance of developing certain side effects, such as mouth sores or digestive issues. This supplementation is intended to be taken only as instructed by a healthcare provider.


Q: Does Metoject stop working over time?

A: Studies and official information indicate that for patients with Rheumatoid Arthritis, an initial clinical improvement is typically maintained for at least two years with continued therapy. Official documents state that if the medicine is discontinued, the symptoms of the treated condition usually worsen within three to six weeks.


Q: What's the main difference between Metoject and methotrexate tablets?

A: Metoject is an injection, and the key difference compared to methotrexate tablets is the way it is absorbed into the body. The injectable form is more consistently and reliably absorbed than the oral tablet. This better absorption may be why some patients experience fewer gastrointestinal side effects and a better overall response.


Q: Can Metoject be used for conditions other than rheumatoid arthritis?

A: Yes, regulatory documents indicate that the medicine is approved for several other inflammatory conditions. These include polyarthritic forms of severe juvenile idiopathic arthritis, severe recalcitrant disabling psoriasis, psoriatic arthritis, and mild to moderate Crohn's disease in adults.


Q: Is it normal to feel a little nauseous after taking Metoject?

A: Yes, nausea is classified as a very common side effect in official regulatory documents. Very common means this effect is experienced by ge 1/10 (10% or more) of patients.


Q: How long does it typically take before I notice Metoject starting to work?

A: According to official product information, the therapeutic response usually begins within three to six weeks of starting treatment. The full benefit of the medicine may be experienced over a longer period.


Q: Does Metoject affect my immune system or make me more likely to get sick?

A: The medicine is classified as an immunosuppressive agent, meaning it works by modulating the activity of the immune system. This suppression can increase the risk of developing serious infections.


Q: If I miss my weekly dose of Metoject, what should I do?

A: Because the medicine is administered on a strict weekly schedule, regulatory guidance advises patients to contact their healthcare provider immediately for instructions about when to take their next dose. This ensures the correct, fixed schedule is maintained.


Q: Does Metoject need to be kept refrigerated?

A: Official labeling states that the medicine should typically be stored below 25 C and should not be frozen. The exact temperature range is documented in the product information.


Q: Can Metoject affect fertility in men or women?

A: Official information reports that the medicine may affect the production of sperm and eggs. This can lead to oligospermia (low sperm count) in men and menstrual dysfunction or amenorrhoea (absence of periods) in women. These effects are often described as reversible upon discontinuation of the medicine.


Q: Are there restrictions on getting vaccines while on Metoject?

A: Yes, regulatory documents state that concurrent vaccination with live vaccines is formally contraindicated during treatment. This is due to the risk of an impaired immune response.


Q: What are the most common reasons why Metoject might be stopped?

A: Official documentation indicates the medicine may be stopped for specific adverse events, such as developing a severe infection, liver disease, respiratory disease, or severe bone marrow suppression. Regulatory constraints indicate the medicine must be stopped if a patient is pregnant or planning for pregnancy.


Q: Are there specific foods I should avoid while taking Metoject?

A: Official regulatory documents do not list specific foods that must be avoided, but the consumption of alcohol is strongly advised against due to severe toxicity risks. Some health authorities note that avoiding unpasteurized foods may be advisable to help reduce the risk of infection, due to the medicine's effects.


Q: Does Metoject cause hair thinning or hair loss?

A: Yes, hair loss (alopecia) is classified as a common side effect in official regulatory documents. Common means this effect is experienced by ge 1/100 to < 1/10 (1% to 10%) of patients.


Q: Can I take Metoject if I am pregnant or planning to become pregnant soon?

A: The medicine is formally contraindicated in pregnancy and breastfeeding due to the potential for harm. Women and men of reproductive potential must use effective contraception during and for a specified time after treatment cessation.


Q: How quickly does Metoject leave the body after the last dose?

A: According to the pharmacokinetic properties described in regulatory documents, the elimination half-life of the medicine is typically between three and ten hours. The half-life is a scientific measure that indicates how quickly the body clears the medicine.


Q: Are there documented cases of Metoject causing depression or mood changes?

A: Official information lists psychiatric side effects as documented adverse reactions. Confusion and depression are classified as uncommon side effects (occurring in ge 1/1000 to < 1/100 of patients).


Q: Can Metoject make existing skin problems worse?

A: Official documentation notes that the medicine can cause severe skin reactions. Official guidance notes that due to the potential for severe skin reactions, caution is advised for patients with existing mucosal or skin issues.


Q: What is the typical duration of treatment with Metoject?

A: The optimal duration of therapy is not uniformly defined; however, limited long-term studies indicate that the beneficial effect of the medicine can be maintained for at least two years with continued use. Treatment length is determined by the patient’s response and tolerability.


Q: If I feel well, can I stop taking Metoject?

A: Clinical information indicates that if the medicine is discontinued, the symptoms of the condition being treated may begin to worsen, typically within three to six weeks. Treatment should only be stopped under the guidance of a healthcare provider.


Q: Are there long-term studies on the safety of Metoject?

A: Official documents reference limited long-term studies. These primarily address the maintenance of effect for at least two years and the continued monitoring necessary for long-term risks like liver toxicity.


Q: Is the injection site reaction (redness/soreness) normal after Metoject?

A: Yes, localized reactions at the injection site are classified as a common side effect in official regulatory documents. This can include pain, redness, and swelling in the area where the medicine was injected.


Q: Does Metoject help reduce inflammation quickly?

A: Official product information indicates that the therapeutic response for conditions like Rheumatoid Arthritis usually begins within three to six weeks of starting treatment. This medicine is not intended for immediate pain relief.


Q: Is there a generic version of Metoject available?

A: The active ingredient in Metoject is methotrexate, and methotrexate is widely available as a generic medication. Specific availability may depend on local health regulations and dispensing practices.

How should Metoject be stored and disposed of?

How to Store and Dispose of Metoject

Storing Metoject (methotrexate) solution for injection requires adherence to specific regulatory conditions to maintain stability and ensure safety.

Storage Requirements

Condition Requirement (Official Labeling)
Temperature Store below 25 C and do not freeze.
Protection Keep in the original outer carton to protect from light.
Safety Keep out of the sight and reach of children.

Disposal Instructions

As a cytotoxic drug, Metoject must be discarded following specific protocols. Do not dispose of the medicine via wastewater or standard household waste. All used Metoject pens and sharps must be placed in a designated cytotoxic sharps bin as required by local hazardous waste regulations. Unused or expired medicine should be returned to a pharmacist for proper disposal.

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

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