Continuation of a randomized, double-blind, multicenter study of linezolid versus vancomycin in the treatment of patients with nosocomial pneumonia.

BACKGROUND: The clinical efficacy and tolerability of linezolid were demonstrated in a previously published, randomized, double-blind, registration study comparing linezolid with vancomycin for the empiric treatment of 396 patients with nosocomial pneumonia. OBJECTIVES: The aims of this study were to obtain additional experience with linezolid and vancomycin in patients with nosocomial pneumonia and to satisfy international regulatory requirements. METHODS: Patients with pneumonia acquired after 48 hours in an inpatient facility were randomly assigned to receive either IV linezolid 600 mg or IV vancomycin 1 g every 12 hours for 7 to 21 consecutive days. Patients also received IV aztreonam 1 to 2 g every 8 hours, which could be discontinued if gram-negative pathogens were not identified. The primary efficacy variables were clinical and microbiologic outcomes in evaluable patients at the follow-up visit 15 to 21 days after the end of therapy. Results from the continuation study were analyzed separately and did not include patients from the previously reported study. RESULTS: A total of 623 patients were enrolled: 321 in the linezolid group and 302 in the vancomycin group. Mean (SD) ages were 63.1 (19.1) years and 61.9 (19.3) years, respectively. Mean (SD) Acute Physiology and Chronic Health Evaluation II scores were 14.1 (5.8) and 14.1 (6.2), respectively. There were no significant differences between the linezolid and vancomycin groups at the follow-up visit in clinical cure rates (114/168 [67.9%] and 111/171 [64.9%]) or microbiologic success rates (47/76 [61.8%] and 42/79 [53.2%]) in evaluable patients (excluding those who had indeterminate or missing outcomes). There were also no significant differences in the rates of all drug-related adverse events (14.0% and 14.0%) or those that occurred in > 1% of patients, including diarrhea (3.7% and 3.0%), nausea (0.3% and 1.3%), and rash (0.6% and 1.7%) in the linezolid and vancomycin groups, respectively. CONCLUSION: In the population studied, linezolid appeared to be as well tolerated and as effective as vancomycin, each in combination with aztreonam.

Worldwide assessment of linezolid's clinical safety and tolerability: comparator-controlled phase III studies.

Linezolid, an oxazolidinone antibiotic, has 100% oral bioavailability and favorable activities against gram-positive pathogens including multidrug-resistant staphylococci, enterococci, and pneumococci. Safety assessments were conducted for 2,046 linezolid-treated patients and 2,001 comparator drug-treated patients from seven controlled clinical trials comparing the activities of linezolid and comparator drugs against nosocomial and community-acquired pneumonia, skin and skin structure infections, and methicillin-resistant staphylococcal infections. Drug-related adverse events were primarily transient. The most frequent (> or = 2%) adverse events caused by linezolid and the comparator drugs were diarrhea (4.3 and 3.2%, respectively; P = 0.074), nausea (3.4 and 2.3%, respectively; P = 0.036), and headache (2.2 and 1.3%, respectively; P = 0.047). Treatment discontinuations due to drug-related events (2.4 and 1.9%, respectively), serious adverse events (11.4 and 10.6%, respectively), and deaths (4.8 and 4.9%, respectively) were similar. No clinically significant drug-related hematologic events were reported, and laboratory safety data were comparable. In the first 6 months of postmarketing surveillance, hematologic abnormalities were reported in 0.1% of linezolid-treated patients, but no irreversible blood dyscrasias were documented. The risk for transient, reversible hematologic effects from treatment with linezolid should be considered together with the clinical benefits associated with its use.

Linezolid versus ceftriaxone/cefpodoxime in patients hospitalized for the treatment of Streptococcus pneumoniae pneumonia.

Intravenous (i.v.) to oral linezolid (600 mg twice daily for both, with optional aztreonam) and a cephalosporin regimen (i.v. ceftriaxone 1 g twice daily followed by oral cefpodoxime 200 mg twice daily) were compared for the treatment of community-acquired pneumonia (CAP), with emphasis on patients with Streptococcus pneumoniae. This multicenter, randomized, open-label trial was conducted in 27 countries in 6 continents. Efficacy was assessed 12-28 d following treatment. Clinical and laboratory safety assessments were evaluated; isolates for microbiologic assessments were identified primarily by sputum or blood culture. In all treated patients (linezolid, n = 381; ceftriaxone/cefpodoxime, n = 366), linezolid had a higher clinical cure rate than ceftriaxone/cefpodoxime (83.0% vs. 76.4%, respectively; p = 0.040). S. pneumoniae was isolated in 73.2% (186/254) of patients at baseline, with similar eradication rates in the linezolid and ceftriaxone/cefpodoxime groups (88.7% vs. 89.9%, respectively; p = 0.830). Linezolid had a superior clinical cure rate (93.1% vs. 68.2%; p = 0.021) in patients with S. pneumoniae bacteremia. Logistic regression analyses revealed that linezolid-treated patients with bacteremia, pleural effusion, cardiac comorbidities, diabetes or abnormal white blood cell counts had significantly better outcomes than cephalosporin-treated patients. Both regimens were well tolerated, although the incidence of drug-related adverse events was higher in the linezolid group than in the ceftriaxone/cefpodoxime group (21.3% vs. 11.2%, respectively; p = 0.0002). In summary, empiric i.v./oral linezolid was more effective than ceftriaxone/cefpodoxime in patients hospitalized with CAP, with comparable cure rates in S. pneumoniae pneumonia and higher cure rates in pneumonia complicated by bacteremia.

Dose--Response Study of Colestipol Tablets in Patients with Moderate Hypercholesterolemia.

The purpose of the study was to evaluate the efficacy and safety of a new formulation of colestipol provided in table form. This was a randomized, double-blind, placebo-controlled, multicenter, dose-ranging study. A total of 196 patients with primary hypercholesterolemia who were following a low-fat, low-cholesterol diet (NCEP Step I diet), and having mean low-density lipoprotein cholesterol (LDL-C) levels greater-than-or-equal4.14 mmol L(minus sign1) (160 mg dl(minus sign1)) and less-than-or-equal6.46 mmol L(minus sign1) (250 mg dl(minus sign1)) were studied. Study medication was taken twice daily, with breakfast and supper, for 8 weeks. The five parallel treatment groups consisted of colestipol tablets 1, 2, 4, and 8 g BID, and matching placebo tablets BID. The main outcome measures were absolute change and percent change from baseline in selected lipid, lipoprotein, and apolipoprotein measurements; LDL-C was considered primary. Statistically significant (p less-than-or-equal 0.05) dose-dependent reductions in LDL-C from 5.2% to 25.8% and in total cholesterol from 2.8% to 16.8% were observed. Colestipol tablet treatment also resulted in statistically significant dose-dependent increases in LpAl levels reaching 25.8% at 16 g day(minus sign1). The treatment was well tolerated, and no serious adverse events were reported. Colestipol administered in tablet form was efficacious in lowering LDL-C and total cholesterol and was well tolerated in patients with primary hypercholesterolemia.