Horn O 200mg/500mg Tablet is a combination antibiotic formulation containing Ofloxacin 200mg and Ornidazole 500mg, indicated for the treatment of mixed bacterial and protozoal infections. Ofloxacin, a fluoroquinolone antibiotic, exerts its effect by inhibiting bacterial DNA gyrase and topoisomerase IV, thereby preventing bacterial replication and transcription. Ornidazole, a nitroimidazole derivative, is effective against anaerobic bacteria and protozoa by disrupting DNA synthesis and causing cell death. This synergistic combination is particularly useful in managing infections where both aerobic and anaerobic pathogens are implicated, such as gastrointestinal infections, genitourinary tract infections, respiratory tract infections, skin and soft tissue infections, and certain sexually transmitted infections. Horn O should be administered as prescribed by a healthcare professional, with dosage adjusted according to the severity of infection and patient-specific factors including renal function. Caution is advised in patients with a history of hypersensitivity to fluoroquinolones or nitroimidazoles. Common adverse effects may include gastrointestinal disturbances, headache, dizziness, and, rarely, tendonitis or neuropathy. It is contraindicated during pregnancy and lactation unless clearly necessary. Proper adherence to the prescribed regimen is essential to prevent resistance development and ensure therapeutic efficacy.