Jylamvo (Methotrexate)

Methotrexate is used across several disease families, primarily targeting immune‑mediated and proliferative disorders.

• Rheumatoid arthritis: reduces joint inflammation and slows disease progression.
• Psoriasis: decreases skin cell turnover and improves plaque lesions.
• Acute lymphoblastic leukemia: interferes with malignant cell replication and supports remission induction.

• Methotrexate inhibits dihydrofolate reductase, blocking the conversion of dihydrofolate to tetrahydrofolate. This reduces the synthesis of purine nucleotides and thymidylate, leading to impaired DNA synthesis and cellular replication. The drug also modulates immune activity by affecting cytokine production and lymphocyte proliferation, contributing to its disease‑modifying effects in autoimmune conditions.

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

Common Side Effects

• Nausea and vomiting: gastrointestinal upset occurring early in therapy.
• Fatigue: persistent tiredness not relieved by rest.
• Oral mucositis: painful sores in the mouth.
• Cytopenias: reduced white blood cells, red blood cells, or platelets.
• Elevated liver enzymes: mild hepatic irritation.
• Alopecia: temporary hair thinning or loss.

Serious or Rare Side Effects

• Severe hepatotoxicity: potential liver fibrosis or cirrhosis.
• Pulmonary toxicity: interstitial pneumonitis or fibrosis.
• Bone marrow suppression: profound pancytopenia.
• Renal failure: impaired drug clearance leading to toxicity.
• Life‑threatening infections: due to immunosuppression.
• Severe cutaneous reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.

When prescribing methotrexate, clinicians should observe several safety measures.

• Liver monitoring: perform baseline and periodic liver function tests.
• Hematologic monitoring: check complete blood counts regularly.
• Renal function: assess creatinine clearance before initiation and during therapy.
• Pregnancy avoidance: contraindicated in pregnancy; ensure effective contraception.
• Dose adjustment: consider lower doses in elderly or patients with organ impairment.
• Store at room temperature: keep in the original container, protect from moisture and heat.

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

Major Interactions (Avoid)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): increase methotrexate serum levels.
• Trimethoprim‑sulfamethoxazole: potentiates bone‑marrow suppression.
• Live vaccines: heightened risk of infection due to immunosuppression.
• High‑dose aspirin: may reduce renal clearance of methotrexate.
• Other folate antagonists (e.g., pemetrexed): additive toxicity.

Moderate Interactions (Monitor Closely)

• Proton‑pump inhibitors: may affect absorption.
• Sulfonamide antibiotics: modest increase in hematologic toxicity.
• Anticonvulsants (e.g., phenytoin): may lower methotrexate levels.
• Allopurinol: can increase risk of skin reactions.
• Cholestyramine: may reduce oral bioavailability.