Metotreksat Ebewe (Methotrexate)

• Methotrexate is used across several disease families, primarily inflammatory and malignant conditions.
• Rheumatoid arthritis: reduces disease activity and slows joint damage progression.
• Psoriasis: decreases skin cell proliferation and improves plaque appearance.
• Acute lymphoblastic leukemia: interferes with cancer cell DNA synthesis to achieve remission.
• Non‑Hodgkin lymphoma: inhibits tumor growth by targeting rapidly dividing lymphoid cells.
• Gestational trophoblastic disease: promotes resolution of abnormal trophoblastic tissue.

• Methotrexate inhibits the enzyme dihydrofolate reductase, leading to reduced tetrahydrofolate levels and impaired synthesis of purine nucleotides and thymidylate. This disruption hampers DNA replication and cell division, particularly in rapidly proliferating immune cells and malignant cells, resulting in immunosuppression and antineoplastic effects.

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

Common Side Effects

• Nausea or vomiting
• Fatigue or malaise
• Mucositis or oral ulceration
• Alopecia (hair loss)
• Elevated liver enzymes
• Mild rash or itching

Serious or Rare Side Effects

• Bone marrow suppression leading to pancytopenia
• Pulmonary toxicity (interstitial pneumonitis)
• Severe hepatotoxicity or fibrosis
• Renal impairment or failure
• Life‑threatening infections
• Severe skin reactions such as Stevens‑Johnson syndrome

• Before initiating therapy, several safety considerations are essential.
• Pregnancy: avoid use unless clearly indicated, as fetal risk is unknown.
• Renal function: assess baseline and monitor regularly; dose adjustment may be required.
• Liver function: monitor transaminases and bilirubin; discontinue if significant elevation occurs.
• Hematologic monitoring: perform complete blood counts to detect marrow suppression.
• Concurrent NSAIDs or nephrotoxic drugs: use with caution due to increased renal toxicity risk.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Methotrexate interacts with several medicines, requiring careful management.

Major Interactions (Avoid)

• Live vaccines: contraindicated due to immunosuppression.
• High‑dose NSAIDs: may increase methotrexate toxicity.
• Trimethoprim‑sulfamethoxazole: additive bone‑marrow suppression.

Moderate Interactions (Monitor Closely)

• Azathioprine: heightened immunosuppressive effect.
• Penicillins: may reduce renal clearance of methotrexate.
• Proton pump inhibitors: can affect methotrexate absorption and excretion.