Lirifax 400 Tablet contains Rifaximin 400 mg, a broad-spectrum, non-absorbable antibiotic primarily used to treat gastrointestinal infections caused by susceptible bacteria. Rifaximin acts by inhibiting bacterial RNA synthesis through binding to the beta-subunit of bacterial DNA-dependent RNA polymerase, leading to bactericidal activity within the intestinal lumen. Due to its minimal systemic absorption, Lirifax 400 is particularly effective in targeting infections localized to the gastrointestinal tract with reduced systemic side effects. It is commonly prescribed for the treatment of travelers’ diarrhea caused by non-invasive strains of Escherichia coli, irritable bowel syndrome with diarrhea (IBS-D), and hepatic encephalopathy to reduce the risk of recurrent episodes by decreasing intestinal ammonia-producing bacteria. The typical dosage and duration depend on the indication and patient condition, with adherence to prescribed regimens essential to prevent bacterial resistance. Lirifax 400 should be used cautiously in patients with hypersensitivity to rifamycins or any component of the formulation. It is contraindicated in patients with severe liver impairment or known hypersensitivity. Common adverse effects include nausea, abdominal pain, and headache, although it is generally well tolerated. Consultation with a healthcare professional is advised prior to initiating therapy to ensure appropriate use and monitoring.