DOI: http://dx.doi.org/10.5915/24-1-1545 1 From January 1987 to July 1989, we prospectively evaluated the safety and efficacy of a fluoroquinolone, ciprofloxacin (Cipro), in the treatment of elderly patients hospitalized with pneumonia. Of the 39 patients, there were 25 females and 14 males, with an age range of 65-94 years (mean age 79.1 years). The four common pathogens were Pseudomonas aeruginosa (12), Streptococcus pneumoniae (5), Haemophilus parainfluenza (5) and Staphylococcus aureus (5). All isolates were sensitive in vitro. Ciprofloxacin was given intravenously (IV) 200 mg every 12 hours. When the patient was able to take oral medication, therapy was switched to oral ciprofloxacin 500 mg every 12 hours. Mean duration of IV/PO therapy was 5.8 days. This study concluded: 1) In the elderly, ciprofloxacin is useful due to convenience of BID dosage, sequential IV/PO availability, good safety and efficacy. 2) Ciprofloxacin shows good in vitro activity. 3) Clinical results are comparable to the results obtained with conventional antimicrobial therapy for treatment of pneumonia in the elderly. 4) All 5/39 ciprofloxain-treated patients with S. pneumoniae as an isolate were cured. 5) Quinolones are cost effective. Early use of oral Cipro in the 39 patients resulted in estimated savings of approximately $6,000. Presented at the IMA 24th Annual Convention Long Island, New York, July 1991