Ceftriaxone is a broad-spectrum cephalosporin antibiotic administered via injection to treat bacterial infections like pneumonia, meningitis, urinary tract infections, and sepsis. It works by inhibiting bacterial cell wall synthesis. Dosage varies by condition, typically given intravenously or intramuscularly. Common side effects include pain at the injection site, nausea, and diarrhea. Always consult a healthcare provider.