Comparative Analysis of Delirium in Older Adults Treated With Ceftazidime, Cefepime, or Ceftriaxone

Inclusion Criteria: * Older adult patients aged 65 years or above. * Hospitalized patients in Alexandria university hospitals diagnosed with infection and treated with selected cephalosporins (Ceftriaxone, Ceftazidime, or Cefepime). * Patients without a history of Pre-existing delirium prior to hospitalization. Exclusion Criteria: * Patients with contraindications or allergies to cephalosporins. * Patients with septic shock. * Current use of medications known to cause delirium (anticholinergics, benzodiazepines, or opioid analgesics). * Current or recent substance abuse (patients with a history of alcohol or drug abuse within the past year, or currently undergoing withdrawal). 5. Recent surgical procedures (patients who have undergone major surgery, particularly those requiring general anesthesia, within the last 30 days). * Electrolyte imbalance (patients with severe electrolyte disturbances such as hypernatremia, hyponatremia, hypercalcemia or hypocalcemia at the time of study entry). * Patients with End-stage renal disease requiring dialysis. * Patients with severe liver disease (e.g., Child-C). * Pain management issues: Patients with severe, uncontrolled pain that might independently affect cognitive function.