Merrel's Panu 40 Tablet contains Pantoprazole 40mg, a proton pump inhibitor used to reduce gastric acid secretion. It is primarily indicated for the treatment of gastroesophageal reflux disease (GERD), erosive esophagitis, Zollinger-Ellison syndrome, and other conditions involving excessive stomach acid production. Pantoprazole acts by selectively inhibiting the H+/K+ ATPase enzyme system at the secretory surface of gastric parietal cells, thereby suppressing the final step in acid production. This results in decreased gastric acidity, promoting healing of acid-related damage and alleviating symptoms such as heartburn, acid regurgitation, and epigastric pain. Merrel's Panu 40 is typically administered orally once daily, preferably before meals, with dosage and duration tailored according to the specific condition and patient response. It is generally well tolerated, with common side effects including headache, diarrhea, nausea, and abdominal discomfort. Caution is advised in patients with liver impairment, and long-term use should be monitored due to potential risks such as vitamin B12 deficiency and increased susceptibility to gastrointestinal infections. Pantoprazole may interact with drugs requiring acidic gastric pH for absorption; therefore, concomitant administration should be managed carefully. Always use Merrel's Panu 40 under medical supervision to ensure safety and efficacy.