CLINICAL EVALUATION OF IMIPENEM/CILASTATIN SODIUM AND FOSFOMYCIN AS SECOND-LINE COMBINATION CHEMOTHERAPY IN SEVERE INFECTIONS ASSOCIATED WITH HEMATOLOGIC DISORDERS

Imipenem/cilastatin sodium (IPM/CS) which is a broadspectrum agent against both Grampositive and-negative bacteria was used in combination with fosfomycin (FOM) as a secondline chemotherapy for severe infections associated with hematologic disorders. FOM was partnered with IPM because FOM may enhance the bacteriocidal effects of IPM when given as pretreatment to IPM/CS therapy. Fifty two patients were treated with IPM/CS plus FOM. Of them, 41 were evaluated for effectiveness. Eleven patients were not evaluated: 4 were treated with a combination of other regimens such as cefixime, γ-globulin, G-CSF and a large dose of methyl predonisolone; 2 were given IPM/CS plus FOM as a first choice; 3 were observed to have gastrointestinal side effects such as nausea which led to the discontinuation of the combination therapy; and 2 were thought to be suffering from not infectious but tumor fever. An excellent response was observed in 15 (36.6%) patients and a good response in 10 (24.4%), for a overall efficacy rate of 61.0%. Efficacies was 71.4% (5/7) in patients with sepsis, and 60.0% (9/15) in patients whose peripheral granulocyte count was below 100/μl before chemotherapy. The elimination rates of Gram-positive and-negative bacteria were 57.1% (4/7) and 75.0% (6/8), respectively. In particular, 75.0% (3/4) of Pseudomonas aeruginosa identified were eliminated. Two patients who suffered from tumor fever, 2 who did not receive chemotherapy before the combination chemotherapy and 3 who did not receive a full course of the combination chemotherapy because of side effects, were included in the final evaluation of safety. Side effects were observed in 18 of 48 patients (37.5%). In 1 patient, skin eruption occurred 3 days after the initiation of the combination chemotherapy. In 17 patients, gastrointestinal symptoms such as nausea and vomiting were identified after a few days of IPM/CS plus FOM administration. Degree's of the symptoms were mild, however. Therefore, the treatment was not withdrawn. No abnormal laboratory results such as eosinophilia, liver disfunction or renal disfunction were observed. These results show that IPM/CS plus FOM is effective as a second-line combination chemotherapy for the treatment of severe infections in patients with hematologic disorders.