Initial antibacterial therapy with imipenem/cilastatin sodium for infections in granulocytopenic patients with hematological diseases

Imipenem/cilastatin sodium (IPM/CS) was used as an initial antibacterial therapy for infections in granulocytopenic patients undergoing ciprofloxacin (CPFX) prophylaxis. Oral CPFX was started at 600 mg daily when peripheral blood granulocytes dropped below 500/μl. As soon as febrile episodes developed, IPM/CS 1 g× 2/d d.i.v. was instituted. As underlying diseases, 28 patients had acute leukemia, myeloblastic or lymphoblastic, 1 chronic melogenous leukemia in blast crisis, 3 myelodysplastic syndrome, and 15 malignant lymphoma. Bacterial infections diagnosed were sepsis in 8 patients, suspected sepsis in 36, and other infections in 3. The overall response rate to this treatment was 80.9%, and those for sepsis, suspected sepsis, and other infectious diseases were 62.5%, 83.3%, and 100%, respectively. This regimen was also effective in 76.9% (10/13) of patients whose granulocyte count remained below 100/μl throughout the course of IPM/CS therapy. The causative organism was identified in 10 infections including 8 sepsis cases; 8 organisms were gram-positive bacteria, and 7 were susceptible. There was no difference in effectiveness between those patients who were receiving G-CSF and those who were not (20/27, 74.1% vs 18/20, 90.0%). As adverse reactions, gastrointestinal tract symptoms such as nausea, vomiting, or anorexia were observed in 7 patients (11.7%), liver function disturbance in 3 (5.0%), and proteinuria in 1 (1.7%), among 60 evaluable episodes. Thus, initial antibacterial therapy with IPM/CS following oral prophylactic use of CPFX is an effective and safe regimen for the treatment of febrile granulocytopenic infections in patients with hematological malignancies.