Imipenem/cilastatin therapy of infections in cancer patients

Imipenem/cilastatin was administered during 153 febrile episodes occurring in cancer patients and the response rate was 68%. Considering only documented infections the response rate was 71%. Patients who received imipenem as initial therapy had a higher response rate than patients who received it after failing other antibiotics (77% versus 68%). The overall response rates for septicemias and pneumonias were 75% and 58%. Among the 57 gram-negative infections 77% responded, but the response rate was substantially higher if imipenem was used as initial therapy (94% versus 69%). The poorest response rate was observed when imipenem was given as secondary therapy for Pseudomonas infections (50%), but most of these patients had failed to respond to other appropriate antibiotics. The only serious side effect was seizures which occurred in ten patients, although eight of them had other predisposing factors. Imipenem appears to be a useful antibiotic for treatment of infections, even in neutropenic cancer patients.     

Endocarditis with ruptured cerebral aneurysm caused by Cardiobacterium valvarum sp. nov

A fastidious gram-negative bacterium was isolated from the blood of a 37-year-old man who had insidious endocarditis with a sudden rupture of a cerebral aneurysm. Characterization of the organism through phylogenetic and phenotypic analyses revealed a novel species of Cardiobacterium, for which the name Cardiobacterium valvarum sp. nov. is proposed. C. valvarum will supplement the current sole species Cardiobacterium hominis, a known cause of endocarditis. Surgeries and antibiotic treatment cured the patient's infection and associated complications. During cardiac surgery, a congenital bicuspid aortic valve was found to be the predisposing factor for his endocarditis.     

Surgical treatment of obstruction of the nasolacrimal ducts in patients with anatomical endonasal variants

The presence of anatomical endonasal variants (concha bullosa, nasal septal deviation, or hypertrophic turbinates) may cause more complications in patients with epiphora who have external dacryocystorhinostomy (DCR). The purpose of this study was to assess the results of surgical placement of a stent in 28 patients. They were randomised into two groups and had either DCR or placement of a Song's polyurethane stent. They were followed up for 18 months. Twenty-six patients had a good result. The success rate was 13/14 for those who had DCR and 13/14 for those who had a stent. Operating time was significantly less for placing a stent (mean (SD) 15 (2) minutes) compared with 40 (3) minutes for DCR (p<0.01). Placement of a polyurethane stent is an effective and short procedure for nasolacrimal obstruction, which is suitable for patients with unusual intranasal conditions.     

Necrotizing gas-forming infections in cancer patients

Necrotizing gas-forming infections in cancer patients present some unique characteristics, such as nontraumatic, spontaneous clostridial gangrene and gangrene involving an ischemic tumor mass. These infections can be rapidly progressive and uniformly fatal without surgical debridement. We review ten cases of gas gangrene seen during an 18-year period. Four were caused by Clostridium species and six by other organisms. Neutropenia was present in seven patients. During the last nine years, Clostridium septicemia occurred in 54 patients; in only two of those patients did gas gangrene ensue.     

Beta-lactam regimens for the febrile neutropenic patient

A total of 535 evaluable febrile episodes in neutropenic patients were randomly assigned to treatment with ticarcillin-clavulanate plus vancomycin (TV), ceftazidime plus vancomycin (CV), or all three antibiotics (TCV). The TCV regimen was significantly more effective than TV, considering all evaluable episodes, documented infections, gram-negative infections, and infections in patients with persistent severe neutropenia (less than 100 neutrophils/mm3). The results with CV were intermediate between TV and TCV. The toxicities were similar with all three regimens and consisted primarily of skin rashes. The TCV regimen is effective for empiric therapy of fever in neutropenic patients and probably should be utilized in preference to CV or TV, although its superiority over CV in this study was inconclusive.     

Clinical pharmacokinetics of aztreonam in cancer patients.

The pharmacokinetics of aztreonam were studied in 25 adult patients with hematological malignancies. Two groups of nine patients each received aztreonam (1 or 2 g every 8 h) prophylactically, and seven infected patients received a therapeutic regimen of aztreonam (1.5 g every 4 h). The mean peak serum concentration after a 1-g dose of aztreonam (given over 0.5 h on day 1) was 75.5 micrograms/ml; after a 2-g dose it was 177.2 micrograms/ml. The mean peak serum concentration after a 1.5-g dose of aztreonam (given over 2 h on day 1) was 68.5 micrograms/ml. The serum half-life ranged between 1.7 and 2.0 h for all regimens studied. The urinary concentration of the metabolite of aztreonam, SQ 26,992, increased during 1 week of administration of the drug; however, serum levels of the metabolite were barely detectable.     

In vitro activity of WIN 49375 compared with those of other antibiotics in isolates from cancer patients

The activity of WIN 49375 [6-fluoro-1, 4-dihydro-1-(methylamino)-7-(4-methyl-1-piperazinyl)-4-oxo-3- quinolinecarboxylic acid], a new synthetic quinolone, was tested in vitro against 587 clinical isolates. The MICs for 90% of isolates of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae were 0.20, 1.56, and 0.39 microgram/ml, respectively. The MICs for 90% of isolates of Pseudomonas aeruginosa and Serratia marcescens were both 3.12 micrograms/ml. WIN 49375 was minimally active against gram-positive cocci. Its in vitro activity suggests that it may be useful for the treatment of gram-negative bacillary infections.