Methotrexate SEDICO

Methotrexate is a widely used medication that acts as a folic acid antagonist, primarily prescribed for the treatment of certain cancers, autoimmune diseases like rheumatoid arthritis, and severe psoriasis. It works by inhibiting cell growth and suppressing the immune system, making it effective in controlling abnormal cell proliferation and inflammation. --- 🔬 What Methotrexate Is - Chemical nature: Methotrexate (MTX), also known as amethopterin, is a synthetic compound derived from folic acid. - Mechanism of action: It inhibits the enzyme dihydrofolate reductase (DHFR), blocking the conversion of folic acid into its active form. This prevents DNA synthesis and cell replication, especially in rapidly dividing cells. - Cell cycle specificity: Its main activity occurs during the S-phase of the cell cycle, where DNA replication takes place. --- 💊 Medical Uses - Cancer treatment: Methotrexate is used against leukemias, lymphomas, breast cancer, lung cancer, and osteosarcoma. - Autoimmune diseases: It is a cornerstone drug for rheumatoid arthritis, reducing joint inflammation and slowing disease progression. - Dermatology: Prescribed for severe psoriasis and other autoimmune skin conditions. - Other uses: Sometimes used in ectopic pregnancy management to stop abnormal tissue growth. --- ⚙️ Pharmacological Details - Administration routes: Oral, intravenous, intramuscular, subcutaneous, and intrathecal (directly into spinal fluid). - Bioavailability: Around 60% at lower doses, decreasing at higher doses. - Metabolism: Primarily hepatic and intracellular. - Excretion: Mostly through urine (80–100%), with small amounts in feces. - Half-life: 3–10 hours at lower doses, 8–15 hours at higher doses. --- ⚠️ Risks and Side Effects - Common side effects: Nausea, fatigue, mouth ulcers, and hair thinning. - Serious risks: Liver toxicity, bone marrow suppression, lung inflammation, and increased susceptibility to infections. - Pregnancy warning