Prophylactic antibiotics for the prevention of early infection in multiple myeloma

Purpose Patients with multiple myeloma are at increased risk for bacterial infection. During the first 2 months of initial chemotherapy the rate of infection is twice that experienced during the remainder of the 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 mortality of early infection can be prevented by prophylactic administration of trimethoprimsulfamethoxazole (TMP-SMX). Patients and methods Eligible patients about to begin chemotherapy for multiple myeloma were randomly assigned to prophylaxis for 2 months or to no prophylaxis (control). Antibiotic prophylaxis consisted of TMP-SMX 160/800 mg orally every 12 hours administered for the first 2 months of initial chemotherapy. All patients were observed for infection for 3 months after the start of chemotherapy. Results Of 57 patients entered into the study, 54 were evaluable, representing 13.1 patient years of observation. The 28 TMP-SMX patients and 26 control patients were comparable in terms of chemotherapy regimen, age, gender, stage, and bone marrow function. Bacterial infection during the 3-month study period occurred in 11 control patients but in only 2 patients assigned TMP-SMX (P = 0.004). Eight 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 with sepsis), 2 urinary tract infections with complicating pneumonia or sepsis, 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 patientyear for controls and 0.29 per patient-year for the TMP-SMX group (P = 0.001). Toxicity (skin rash 6 patients, nausea 1 patient) was not lifethreatening but required discontinuation of TMPSMX in 25% of patients. conclusion: Administering TMP-SMX for the first 2 months of initial chemotherapy is effective, inexpensive prophylaxis for early bacterial infection in multiple myeloma.