Methotrexate Medac (Methotrexate)

Methotrexate Medac acts as a folate antagonist and is indicated for several oncologic and autoimmune disease pathways.

• Rheumatoid arthritis: reduces joint inflammation and slows disease progression.
• Psoriasis: improves skin lesions and decreases scaling.
• Acute lymphoblastic leukemia: induces remission by inhibiting malignant cell proliferation.
• Non‑Hodgkin lymphoma: contributes to tumor control as part of combination therapy.
• Breast cancer: used in multi‑drug regimens to limit tumor growth.

• Methotrexate inhibits dihydrofolate reductase, preventing the regeneration of tetrahydrofolate. This blocks the synthesis of purine nucleotides and thymidylate, impairing DNA, RNA and protein production. The resulting cytotoxic effect preferentially targets rapidly dividing cells and also suppresses immune cell proliferation, providing both antineoplastic and immunosuppressive actions.

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

Common Side Effects

• Nausea and vomiting.
• Fatigue and malaise.
• Mucositis (mouth sores).
• Alopecia (hair loss).
• Elevated liver enzymes.
• Mild skin rash.

Serious or Rare Side Effects

• Bone marrow suppression leading to pancytopenia.
• Severe infections due to immunosuppression.
• Pulmonary toxicity (interstitial pneumonitis).
• Hepatotoxicity with fibrosis or cirrhosis.
• Renal toxicity, especially with high doses.
• Life‑threatening cutaneous reactions such as Stevens‑Johnson syndrome.

Before initiating therapy, clinicians should assess baseline status and monitor patients regularly.

• Monitor blood counts: perform complete blood count before each dose.
• Assess liver function: check transaminases and bilirubin regularly.
• Evaluate renal function: monitor serum creatinine and adjust dose if needed.
• Avoid use in active infections: treat infections prior to dosing.
• Use effective contraception: methotrexate is teratogenic.
• Store at ambient temperature: keep in original container, protect from moisture and light.

Methotrexate interacts with several medicines that may increase toxicity or reduce efficacy.

Major Interactions (Avoid)

• Non‑steroidal anti‑inflammatory drugs (NSAIDs): increase methotrexate serum levels.
• Penicillins (e.g., ampicillin): may reduce renal clearance.
• Sulfonamide antibiotics: additive bone‑marrow suppression.
• Live vaccines: risk of severe infection.

Moderate Interactions (Monitor Closely)

• Azathioprine: enhanced immunosuppression.
• Cyclosporine: increased risk of nephrotoxicity.
• Proton‑pump inhibitors: may affect renal elimination.
• Warfarin: potential for altered anticoagulant effect.