Lefuma 20mg Tablet contains Leflunomide, an immunomodulatory agent primarily indicated for the treatment of active rheumatoid arthritis and psoriatic arthritis in adults. Leflunomide functions by inhibiting dihydroorotate dehydrogenase, a key enzyme involved in pyrimidine synthesis, thereby reducing the proliferation of activated lymphocytes responsible for the inflammatory process in autoimmune conditions. This mechanism helps to decrease joint inflammation, pain, and structural damage associated with these diseases. Lefuma 20mg is administered orally, with dosage adjustments based on clinical response and tolerability. It is essential to monitor liver function tests and complete blood counts regularly during therapy due to potential hepatotoxicity and hematologic adverse effects. Leflunomide is contraindicated in patients with severe hepatic impairment, pregnancy, or hypersensitivity to the drug. Common side effects include diarrhea, alopecia, rash, and elevated liver enzymes. Patients should be advised on the importance of contraception during and after treatment due to teratogenic risks. Lefuma 20mg Tablet offers a valuable therapeutic option for managing autoimmune arthritis by modulating the immune response, improving symptoms, and enhancing quality of life in affected individuals under appropriate medical supervision.