PROPHYLACTIC ANTIBIOTICS FOR THE PREVENTION OF EARLY INFECTION IN MULTIPLE-MYELOMA

PURPOSE: Patients with multiple myeloma are at increased risk for bact erial infection. During the first 2 months of initial chemotherapy the rate of infection is twice that experienced during the remainder of t he disease course. As many as one-third of these early infections are fatal, and many more prevent adequate administration of chemotherapy. This study was designed to determine whether the morbidity and mortali ty of early infection can be prevented by prophylactic administration of trimethoprim-sulfamethoxazole (TMP-SMX). PATIENTS AND METHODS: Elig ible patients about to begin chemotherapy for multiple myeloma were ra ndomly assigned to prophylaxis for 2 months or to no prophylaxis (cont rol). Antibiotic prophylaxis consisted of TMP-SMX 160/800 mg orally ev ery 12 hours administered for the first 2 months of initial chemothera py. All patients were observed for infection for 3 months after the st art of chemotherapy. RESULTS: Of 57 patients entered into the study, 5 4 were evaluable, representing 13.1 patient-years of observation. The 28 TMP-SMX patients and 26 control patients were comparable in terms o f chemotherapy regimen, age, gender, stage, and bone marrow function. Bacterial infection during the 3-month study period occurred in 11 con trol patients but in only 2 patients assigned TMP-SMX (P = 0.004). Eig ht severe infections occurred in controls compared with 1 in a TMP-SMX patient (P = 0.010) leading to 4 and 1 infection deaths, respectively (P = not significant). Severe infections included 5 pneumonias (3 wit h sepsis), 2 urinary tract infections with complicating pneumonia or s epsis, 1 diverticulitis with perforation, and 1 staphylococcal scalded skin syndrome. None of the 4 nonbacterial infections was severe. The rate of bacterial infection was 2.43 per patient-year for controls and 0.29 per patient-year for the TMP-SMX group (P = 0.001). Toxicity (sk in rash 6 patients, nausea 1 patient) was not life-threatening but req uired discontinuation of TMP-SMX in 25% of patients. CONCLUSION: Admin istering TMP-SMX for the first 2 months of initial chemotherapy is eff ective, inexpensive prophylaxis for early bacterial infection in multi ple myeloma.