Ledertrexate (Methotrexate Disodium)

Ledertrexate, an antimetabolite, is indicated for several immune‑mediated and oncologic conditions.

• Rheumatoid arthritis: reduces joint inflammation and slows disease progression.
• Psoriasis: diminishes skin lesions and plaque formation.
• Acute lymphoblastic leukemia: interferes with malignant cell proliferation.
• Non‑Hodgkin lymphoma: impedes growth of lymphoid tumor cells.
• Gestational trophoblastic disease: promotes resolution of abnormal trophoblastic tissue.

• Methotrexate Disodium inhibits dihydrofolate reductase, blocking the conversion of dihydrofolate to tetrahydrofolate. This limits the synthesis of purine nucleotides and thymidylate, leading to reduced DNA replication and cell division, particularly in rapidly proliferating immune and malignant cells.

Adverse reactions can range from mild to severe and should be monitored throughout therapy.

Common Side Effects

• Nausea and vomiting.
• Fatigue or malaise.
• Oral mucosal ulceration.
• Transient elevation of liver enzymes.
• Mild cytopenias (e.g., reduced white blood cells).
• Alopecia (hair thinning or loss).

Serious or Rare Side Effects

• Severe hepatotoxicity or hepatic fibrosis.
• Pulmonary toxicity, including interstitial pneumonitis.
• Life‑threatening bone marrow suppression.
• Acute renal failure.
• Severe cutaneous reactions such as Stevens‑Johnson syndrome.
• Opportunistic infections due to profound immunosuppression.

Before initiating therapy, clinicians should assess baseline organ function and counsel patients on safety measures.

• Monitor liver function: perform baseline and periodic liver enzyme tests.
• Assess renal function: evaluate serum creatinine and adjust dose if needed.
• Check complete blood count: watch for anemia, leukopenia, or thrombocytopenia.
• Avoid use in pregnancy: contraindicated unless benefits outweigh risks.
• Use effective contraception: women of childbearing potential must employ reliable birth control.
• Store at room temperature: keep in the original container, protect from moisture and light.

Methotrexate interacts with several drug classes; some combinations require avoidance while others need close monitoring.

Major Interactions (Avoid)

• Live vaccines: increased risk of severe infection.
• NSAIDs (e.g., ibuprofen, naproxen): heightened methotrexate toxicity.
• Penicillins and sulfonamides: may raise plasma methotrexate concentrations.

Moderate Interactions (Monitor Closely)

• Proton pump inhibitors: can affect methotrexate absorption.
• Azathioprine or other immunosuppressants: additive bone‑marrow suppression.
• Warfarin: enhanced anticoagulant effect, requiring INR monitoring.