Lantarel (Methotrexate Disodium)

Methotrexate Disodium is a folate‑antagonist used in several immune‑mediated and oncologic conditions.

• Rheumatoid arthritis: reduces joint inflammation and slows structural damage.
• Psoriasis: decreases skin cell proliferation and improves plaque lesions.
• Acute lymphoblastic leukemia: interferes with malignant cell replication as part of combination chemotherapy.
• Non‑Hodgkin lymphoma: provides cytotoxic activity against rapidly dividing lymphoid cells.

• Methotrexate Disodium competitively inhibits dihydrofolate reductase, preventing the conversion of dihydrofolate to tetrahydrofolate. This reduction limits the synthesis of purine nucleotides and thymidylate, impairing DNA, RNA and protein production in rapidly dividing cells. The resulting antiproliferative effect modulates immune cell activity and induces apoptosis in malignant lymphoid cells.

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

Common Side Effects

• Nausea: mild to moderate gastrointestinal upset.
• Fatigue: general tiredness or weakness.
• Mouth sores: ulceration of oral mucosa.
• Elevated liver enzymes: mild hepatic enzyme rise.
• Low blood counts: mild leukopenia or anemia.

Serious or Rare Side Effects

• Severe liver toxicity: potential hepatitis or fibrosis.
• Pulmonary fibrosis: interstitial lung disease with breathing difficulty.
• Renal impairment: reduced kidney function or acute nephrotoxicity.
• Bone marrow suppression: severe pancytopenia.
• Severe cutaneous reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.

When prescribing Methotrexate Disodium, clinicians should observe several safety measures to minimize risk.

• Baseline testing: obtain liver function, renal function and complete blood count before initiation.
• Pregnancy avoidance: contraindicated in pregnancy; ensure effective contraception for both sexes.
• Monitoring: perform regular laboratory assessments of hepatic, renal and hematologic parameters.
• Drug interactions: review concomitant medications that may increase toxicity, such as NSAIDs or penicillins.
• Patient education: advise on signs of infection, liver dysfunction and pulmonary symptoms.
• Store at ambient temperature: keep tablets in original packaging, protect from moisture and light.

Methotrexate Disodium has notable interactions that can alter its efficacy or increase toxicity.

Major Interactions (Avoid)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): may increase methotrexate plasma levels and risk of toxicity.
• Proton pump inhibitors (e.g., omeprazole): can reduce renal clearance, enhancing toxicity.
• Trimethoprim‑sulfamethoxazole: potentiates myelosuppression.

Moderate Interactions (Monitor Closely)

• Azathioprine: additive immunosuppression may increase infection risk.
• Live vaccines: reduced efficacy and potential for infection.
• Vitamin supplements containing folic acid: may diminish therapeutic effect; adjust dosing under supervision.