Introduction: The efficacy and safety of oral ofloxacin were compared with those of vancomycin/polymyxin for prophylaxis of bacterial infections in granulocytopenic patients undergoing chemotherapy for hematologic malignancy.
Patients and methods: Antimicrobial prophylaxis was begun at the time of initiation of chemotherapy. Thirty patients received ofloxacin tablets (300 mg orally every 12 hours) plus a nystatin suspension. Thirty-two patients received vancomycin capsules (500 mg orally every eight hours) and polymyxin capsules (100 mg orally every eight hours) plus a nystatin suspension.
Results: In the group of patients receiving ofloxacin, there were a lower number of acquired gram-negative bacillary organisms per patient (0.13 versus 1.37, p less than 0.00005), fewer patients with documented infection (11 of 30 versus 21 of 32, p = 0.04), and fewer cases of gram-negative septicemia (zero of 30 versus five of 32, p = 0.05). Ofloxacin was also better tolerated (24 of 30 versus 10 of 32 patients highly compliant, p = 0.01) and associated with fewer gastrointestinal side effects (one of 30 versus nine of 32 patients with gastrointestinal side effects, p = 0.01) than vancomycin/polymyxin. However, except for a reduction of Staphylococcus aureus colonization and infection by ofloxacin, neither ofloxacin nor vancomycin/polymyxin was effective in eliminating colonization or infection with viridans group streptococci, coagulase-negative staphylococci, or other gram-positive organisms. Only three isolates of ofloxacin-resistant gram-negative bacteria (Pseudomonas fluorescens, Pseudomonas putida, and Enterobacter aerogenes) were isolated from surveillance cultures, but none caused infection.
Conclusion: These results suggest that oral ofloxacin is a more tolerable and efficacious alternative to vancomycin/polymyxin for prevention of serious gram-negative bacillary infections in granulocytopenic patients. More effective prophylaxis of gram-positive infections, however, is still needed.