Erlonat 150 Tablet contains Erlotinib 150 mg, a potent epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor used primarily in the treatment of non-small cell lung cancer (NSCLC) and pancreatic cancer. Erlotinib functions by selectively inhibiting the intracellular phosphorylation of EGFR, thereby blocking signal transduction pathways involved in the proliferation and survival of cancer cells. This targeted therapy is indicated for patients with locally advanced or metastatic NSCLC after failure of at least one prior chemotherapy regimen and as a first-line treatment in patients with EGFR mutation-positive tumors. Additionally, Erlotinib is used in combination with gemcitabine for locally advanced, unresectable, or metastatic pancreatic cancer. The recommended dose is 150 mg orally once daily, taken on an empty stomach to optimize absorption. Common adverse effects include rash, diarrhea, anorexia, and fatigue, which are generally manageable with supportive care. Serious adverse reactions may involve interstitial lung disease, hepatotoxicity, and gastrointestinal perforation, necessitating close monitoring during therapy. Erlonat 150 Tablet should be prescribed and administered under the supervision of an oncologist, with regular assessment of therapeutic response and toxicity to ensure optimal clinical outcomes. Patients should be counseled on adherence and potential side effects to maximize treatment efficacy.