Methotrexate Accord Healthcare (Methotrexate)

Methotrexate acts on rapidly dividing cells and immune pathways, making it useful across several disease families.

• Rheumatoid arthritis: reduces joint inflammation and slows disease progression.
• Psoriasis: limits skin cell proliferation, improving plaque severity.
• Acute lymphoblastic leukemia: interferes with malignant lymphoblast replication.
• Non‑Hodgkin lymphoma: hampers growth of lymphoma cells.
• Gestational trophoblastic disease: induces remission by targeting trophoblastic tissue.

• Methotrexate inhibits dihydrofolate reductase, preventing conversion of dihydrofolate to tetrahydrofolate. This blockade reduces synthesis of purine nucleotides and thymidylate, leading to impaired DNA, RNA and protein production. The resulting inhibition of cell division affects rapidly proliferating immune cells and malignant cells, providing both immunosuppressive and antineoplastic effects.

Methotrexate may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Nausea and vomiting: gastrointestinal upset occurring shortly after administration.
• Fatigue: persistent tiredness not relieved by rest.
• Oral mucositis: painful mouth sores and ulceration.
• Elevated liver enzymes: mild hepatic enzyme rise detectable on labs.
• Cytopenias: reduced white blood cells or platelets.

Serious or Rare Side Effects

• Severe hepatotoxicity: potential liver injury requiring monitoring.
• Pulmonary fibrosis: interstitial lung disease with breathlessness.
• Bone marrow aplasia: profound suppression of blood cell production.
• Renal failure: impaired kidney function, especially with high doses.
• Severe cutaneous reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.

Careful monitoring and patient education are essential when using Methotrexate.

• Liver monitoring: perform baseline and periodic liver function tests.
• Hematologic surveillance: check complete blood counts regularly.
• Pregnancy avoidance: contraindicated in pregnancy; ensure effective contraception.
• Renal function: assess creatinine clearance before dose adjustments.
• Drug interactions: review concomitant medications for potential additive toxicity.
• Store at ambient temperature: keep in original container, protect from moisture and direct sunlight.

Methotrexate interacts with several medicines that can alter its safety or efficacy.

Major Interactions (Avoid)

• NSAIDs (e.g., ibuprofen, naproxen): increase methotrexate toxicity by reducing renal clearance.
• Trimethoprim‑sulfamethoxazole: heightens risk of bone‑marrow suppression.
• Live vaccines: may cause uncontrolled infection due to immunosuppression.

Moderate Interactions (Monitor Closely)

• Penicillins (e.g., amoxicillin): may modestly raise methotrexate levels.
• Azathioprine: additive immunosuppressive effect, requiring blood count monitoring.
• Phenytoin: can reduce methotrexate efficacy, necessitating therapeutic assessment.