Linezolid versus vancomycin in the treatment of known or suspected resistant gram-positive infections in neonates.

BACKGROUND: Gram-positive infections caused by susceptible and resistant strains of Staphylococcus aureus, coagulase-negative staphylococci and enterococci are increasing problems in neonates. Linezolid, a new oxazolidinone, is active against these pathogens and has recently been approved by the Food and Drug Administration for treating Gram-positive infections in pediatric patients. OBJECTIVE: To compare the clinical efficacy and safety of intravenous and oral linezolid with vancomycin (10 to 15 mg/kg every 6 to 24 h) in neonates (age 0 to 90 days). METHODS: Hospitalized infants with known or suspected hospital-acquired pneumonia, complicated skin or skin structure infections, bacteremia or other infections (e.g. pyelonephritis, abdominal abscess) were eligible. Test-of-cure clinical response was evaluated at follow-up. RESULTS: Sixty-three neonates, randomized 2:1 to linezolid (n = 43) or vancomycin (n = 20) were included in the intent-to-treat group. Clinical cure rates at follow-up in the intent-to-treat group were higher, but not significantly different, for linezolid vs. vancomycin (78% vs. 61%; P = 0.196). Corresponding cure rates in clinically evaluable patients were 84% vs. 77% (P = 0.553) for linezolid and vancomycin, respectively. Pathogen eradication rates were as follows in the linezolid and vancomycin groups, respectively: S. aureus (67% vs. 60%; P = 0.850); coagulase-negative staphylococci (88% vs. 100%; P = 0.379); and enterococci (71% vs. 0%; P = 0.168). Results for hematology and chemistry assays were similar between treatment groups. Fewer linezolid-treated neonates had drug-related adverse events than vancomycin-treated neonates (12% vs. 32%; P = 0.058). CONCLUSIONS: Linezolid is well-tolerated and as effective as vancomycin in the treatment of resistant Gram-positive infections in neonates.

Linezolid for the treatment of children with bacteremia or nosocomial pneumonia caused by resistant gram-positive bacterial pathogens.

BACKGROUND: Nosocomial infections, particularly hospital-acquired pneumonia (HAP) and bacteremia, are an increasing concern in pediatric hospitals and pediatric intensive care units. Gram-positive pathogens are a leading cause of these infections in children. Linezolid is well-tolerated and as effective as vancomycin in the treatment of these infections in adults. OBJECTIVE: To evaluate the clinical effectiveness and safety of iv/oral linezolid and iv vancomycin in children with resistant Gram-positive HAP or bacteremia. METHODS: Hospitalized children <12 years of age were randomized 2:1 to linezolid or vancomycin. Patients received linezolid 10 mg/kg iv every 8 h with the option to change treatment to oral linezolid suspension 10 mg/kg every 8 h or iv vancomycin 10 to 15 mg/kg every 6 to 24 h. Clinical response was evaluated at follow-up. Results from an analysis of patients with HAP or bacteremia are presented. RESULTS: Thirty-nine patients (linezolid, 23; vancomycin, 16) with HAP and 113 patients with bacteremia (linezolid, 81; vancomycin, 32) were included in the intent-to-treat group. Clinical cure rates for clinically evaluable patients with HAP did not differ between treatment groups (linezolid, 90.0% and vancomycin, 100%; P = 0.305). No significant difference was seen in clinical cure rates in the clinically evaluable population between the linezolid and vancomycin groups for patients with catheter-related bacteremia (84.8 and 80.0%, respectively; P = 0.716) or patients with bacteremia of unknown source (79.2 and 69.2%, respectively; P = 0.501). In this subset fewer linezolid-treated patients had drug-related adverse events than did vancomycin-treated patients (19.4% vs. 28.3%; P = 0.230). Similar percentages of patients with laboratory abnormalities, including selected hematologic parameters, were seen in both treatment groups. CONCLUSIONS: Intravenous/oral linezolid was well-tolerated and as effective as vancomycin in treating children with resistant Gram-positive HAP or bacteremia.

Linezolid for the treatment of complicated skin and skin structure infections in children.

BACKGROUND: Gram-positive pathogens are a major cause of complicated skin and skin structure infections (CSSSIs) in children. Many pathogens are developing decreased susceptibility to currently used antibiotics, increasing the need for new therapies. Linezolid is well-tolerated and effective in the treatment of these infections in adults. OBJECTIVE: To evaluate the clinical efficacy and safety of iv/oral linezolid and iv vancomycin in children with Gram-positive CSSSIs. METHODS: Hospitalized children <12 years of age were randomized (2:1 ratio) to receive either linezolid 10 mg/kg iv every 8 h (with the option to change treatment to oral linezolid suspension 10 mg/kg every 8 h) or iv vancomycin 10 to 15 mg/kg every 6 to 24 h (according to age). Clinical response, tolerance and safety were evaluated at follow-up. The results of a subset analysis of patients with CSSSIs are presented here. RESULTS: One hundred twenty intent-to-treat patients (linezolid 80, vancomycin 40) with CSSSI were included in this analysis. Clinical cure rates for clinically evaluable patients with CSSSI did not differ between treatment groups (linezolid, 93.2% vs. vancomycin, 90.0%; P = 0.594). Significantly fewer linezolid-treated patients experienced drug-related adverse events than did vancomycin-treated patients (23% vs. 48%; P = 0.006). The percentages of patients with laboratory abnormalities, including selected hematologic parameters, were generally low and similar between the treatment groups. CONCLUSIONS: Linezolid given iv or orally was well-tolerated and safe. It was as effective as vancomycin in treating children with Gram-positive CSSSIs.

Hematologic effects of linezolid in young children.

BACKGROUND: Linezolid is an effective and well-tolerated antibiotic for the treatment of Gram-positive infections, including hospital and community-acquired pneumonia and complicated and uncomplicated skin and skin structure infections. In adults linezolid treatment for >/=2 weeks has been associated with reversible hematopoietic suppression, primarily thrombocytopenia. OBJECTIVE: To evaluate the occurrence of hematologic effects in children with Gram-positive infections in an open label study of linezolid vs. vancomycin. METHODS: Detailed analyses of hematologic data, including reported hematologic adverse events, complete blood counts, reticulocyte index (RI) and iron studies (serum iron and transferrin saturation), were conducted in both groups at baseline and during and after treatment with the use of an intent-to-treat analysis. RESULTS: Three hundred sixteen patients (median age, 1.65 yr) randomized 2:1 to linezolid (n = 215) or vancomycin (n = 101) were treated. Total treatment durations were similar in the vancomycin group (12.2 +/- 6.4 days; median, 11.0 days) and the linezolid group (11.3 +/- 5.0 days; median, 11.0 days) (P = 0.20). No significant differences were noted in drug-related hematologic events, such as thrombocytopenia (linezolid, 1.9% vs. vancomycin, 0%; P = 0.170), anemia (linezolid, 1.4% vs. vancomycin, 1.0%; P = 0.771) or neutropenia (linezolid, 0% vs. vancomycin, 0%). Hemoglobin values also were similar between treatment groups when assessed by shifts from baseline to lowest recorded value. Frequency of occurrence of any substantially abnormal value for hemoglobin (15.7% vs. 12.4%), platelets (12.9% vs. 13.4%) and neutrophils (5.9% vs. 4.3%) were similar in the linezolid and vancomycin groups. No clinically relevant changes in RI or iron studies were noted between treatment groups, and parallel increases in RI occurred with both linezolid and vancomycin. CONCLUSIONS: No significant differences in hematologic profiles between linezolid and vancomycin occurred in this pediatric population.