Zostum O 100mg Dry Syrup contains Cefditoren, a third-generation oral cephalosporin antibiotic with broad-spectrum activity against various Gram-positive and Gram-negative bacteria. It is indicated for the treatment of respiratory tract infections such as community-acquired pneumonia, acute exacerbations of chronic bronchitis, and pharyngitis/tonsillitis caused by susceptible organisms. Cefditoren exerts its bactericidal effect by inhibiting bacterial cell wall synthesis, leading to cell lysis and death. The dry syrup formulation allows for convenient administration in pediatric patients or those with difficulty swallowing tablets. After reconstitution, Zostum O should be stored as per guidelines and used within the recommended period to maintain efficacy. Dosage and duration of therapy should be determined based on the severity of infection, patient age, weight, and renal function. Common adverse effects may include gastrointestinal disturbances such as diarrhea, nausea, and abdominal pain, while hypersensitivity reactions are rare but possible. It is contraindicated in patients with a known allergy to cephalosporins or penicillins. Caution is advised in patients with a history of gastrointestinal disease, particularly colitis. Zostum O 100mg Dry Syrup should be used under medical supervision to ensure appropriate antimicrobial stewardship and optimal therapeutic outcomes.