Case Presentation: A 66 year old female with history of Multiple Sclerosis and Sjogren’s syndrome presented with fever, hypotension and abdominal pain and was admitted for severe urosepsis secondary to a urinary tract infection. On imaging, she was found to have hydronephrosis with an obstructing distal right ureteral calculus and underwent a cytoscopy with ureteral stent placement. Two days later, when the blood and urine cultures grew pan-sensitive E. Coli, the antibiotics were changed from IV Piperacillin/Tazobactam to oral Levofloxacin. Within a day of starting Levofloxacin, the patient developed acute mental status changes that included disorientation, paranoid delusions, visual hallucinations, a bizarre and tangential thought process as well as physical agitation. The patient had no past psychiatric history or any reported events of delirium. Over the next two days, all usual causes of delirium were meticulously addressed with no change in clinical status. On day 3 of these symptoms, Levofloxacin was switched to Cefixime and the patient improved over the next 24-36 hours as evidenced by her improved orientation, ability to focus, decreased reference to unusual hallucinations and internal stimuli, and decreased agitation. The patient was discharged home at baseline mental status.
Discussion: The new quinolone derivatives (such as Levofloxacin) are known for their potential to cause central nervous system-related adverse effects, including headache, dizziness and insomnia. Risk factors for neurotoxicity include renal insufficiency, underlying central nervous system (CNS) disease and increased CNS penetration of drug. There have been scarce reports of Levofloxacin induced acute psychosis which presents within a few days of starting Levofloxacin and symptoms resolving within 48 hours of discontinuing the antibiotic. Acute delirium resulting from Levofloxacin therapy is an exceedingly rare complication that has been thought to occur more commonly in elderly patients. To the best of our knowledge, this is one of the few cases of Levofloxacin induced delirium observed in the medical literature.
Conclusions: Fluoroquinolones are antibiotics used with relative frequency in adult hospital medicine, especially for the treatment of pneumonia and urinary tract infections. Patients >65 years of age comprise 40% hospitalized adults and nearly half of all health care dollars spent on hospitalization. In addition to the other more common side effects associated with fluoroquinolones, hospitalists should be aware of these drugs’ potential to cause delirium in an at-risk elderly population, thereby increasing lengths of admission and delaying return to baseline for this population.