Once daily antibiotic regimen in paediatric oncology

Teicoplanin versus vancomycin for proven or suspected infection

BACKGROUND

Vancomycin and teicoplanin are commonly used to treat gram-positive infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA). There is uncertainty regarding the effects of teicoplanin compared to vancomycin on kidney function with some previous studies suggesting teicoplanin is less nephrotoxic than vancomycin.

OBJECTIVES

To investigate the efficacy and safety of vancomycin versus teicoplanin in patients with proven or suspected infection.

SEARCH STRATEGY

We searched the Cochrane Renal Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, reference lists of nephrology textbooks, review articles with relevant studies and sent letters seeking information about unpublished or incomplete studies to investigators involved in previous studies.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) in any language comparing teicoplanin to vancomycin for patients with proven or suspected infection.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated methodological quality and extracted data using standardised data extraction forms. Study investigators were contacted for information not available in the original manuscripts. Random effects model was used to estimate the pooled risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 24 studies (2,610 patients) in this review. Teicoplanin reduced the risk of nephrotoxicity compared to vancomycin (RR 0.66, 95% CI 0.48 to 0.90).The effects of teicoplanin or vancomycin were similar for clinical cure (RR 1.03, 95% CI 0.98 to 1.08), microbiological cure (RR 0.98, 95% CI 0.93 to 1.03) and mortality (RR 1.02, 95% CI 0.79 to1.30). Six studies reported no cases of acute kidney injury (AKI) needing dialysis. Adverse events were less frequent with teicoplanin including cutaneous rash (RR 0.57, 95% CI 0.35 to 0.92), red man syndrome (RR 0.21, 95% CI 0.08 to 0.59) and total adverse events (RR 0.73, 95% CI 0.53 to 1.00). A lower risk of nephrotoxicity with teicoplanin was observed in patients either with (RR 0.51, 95% CI 0.30 to 0.88) or without aminoglycosides (RR 0.31, 95% 0.07 to 1.50), and also when vancomycin dosing was guided by serum levels (RR 0.22, 95% CI 0.10 to 0.52).

AUTHORS' CONCLUSIONS

Teicoplanin and vancomycin are both effective in treating those with proven or suspected infection; however the incidence of adverse effects including nephrotoxicity was lower with teicoplanin. There were no cases of AKI needing dialysis. It remains unclear whether the differential effect on kidney function should influence which antibiotic be prescribed, although it may be reasonable to consider teicoplanin for patients at higher risk for AKI needing dialysis.

The evolution towards ambulatory and day-case management of febrile neutropenia

Febrile neutropenia (FN) is only second to chemotherapy administration as a cause of hospital admission during treatment for cancer. As FN may signify serious or life-threatening infection, management protocols have focussed on trying to prevent adverse outcomes in these patients. However, it is now possible to identify a subset of patients with FN at low risk of life-threatening complications in whom duration of hospitalisation and intensity of therapy can be reduced safely. This review discusses how the management of FN has evolved to enable patients identified as low risk to be treated on specific low risk management strategies, with an emphasis on some of the practical considerations for the implementation of such strategies.

Tobramycin Pharmacokinetics in Children with Febrile Neutropenia Undergoing Stem Cell Transplantation: Once-Daily versus Thrice-Daily Administration

STUDY OBJECTIVE

To describe the pharmacokinetic disposition of tobramycin in children undergoing stem cell transplantation (SCT) after intravenous administration either every 24 hours or every 8 hours, and to use this information to create initial dosing guidelines for administration every 24 hours in this patient population.

DESIGN

Pharmacokinetic analysis of a randomized controlled trial.

SETTING

The Hospital for Sick Children, Toronto, Ontario, Canada.

PATIENTS

Sixty children (< 18 yrs) with febrile neutropenia undergoing stem cell transplantation.

INTERVENTION

Patients were randomized to receive intravenous tobramycin either every 24 hours (29 patients) or every 8 hours (31 patients). Initially, they received either 2.5 mg/kg/dose every 8 hours or weight-based doses by age group (< 5 yrs, 9 mg/kg/dose; 5 to < 12 yrs, 8 mg/kg/dose; > or = 12 yrs, 7 mg/kg/dose) every 24 hours.

MEASUREMENTS AND MAIN RESULTS

Serum tobramycin concentrations were obtained at 2 and 8 hours after the first dose. Initial guidelines for dosing every 24 hours were derived using the parameters from all patients to achieve a maximum serum concentration (Cmax) of 20-22.5 mg/L and a drug-free interval (time during dosing interval when the tobramycin concentration was < 1 mg/L) of at least 4 hours. After the first tobramycin dose, the elimination rate constant (kel) and volume of distribution (Vd) observed in the every-8-hour group (23 patients) were 0.34 +/- 0.09 hours(-1) and 0.48 +/- 0.21 L/kg, respectively. The kel and Vd in the every-24-hour group (22 patients) were 0.43 +/- 0.12 hr(-1) and 0.43 +/- 0.26 L/kg, respectively. Tobramycin Vd varied with age. Initial doses of tobramycin every 24 hours recommended to achieve the target parameters are 10 mg/kg/dose for patients aged 6 months to less than 9 years, 8 mg/kg/dose for those aged 9 to less than 12 years, and 6 mg/kg/dose for those aged 12 years or older.

CONCLUSION

Children undergoing SCT who receive tobramycin every 24 hours should receive an initial dose based on age. Further validation of the proposed dosing guidelines is required.

Clinical issues surrounding once-daily aminoglycoside dosing in children

Aminoglycoside antibiotics are first-line treatment for many infectious diseases in the pediatric population and are effective in adults. The traditional dosing interval in children is every 8-12 hours. Studies in adults reported equivalent efficacy and equal or less toxicity with once-daily regimens. Despite many studies in the adult population, this approach has yet to become standard practice in most pediatric hospitals. Reasons for lack of acceptance of this strategy in children include rapid aminoglycoside clearance, unknown duration of postantibiotic effect, safety concerns, and limited clinical and efficacy data.

Efficacy and tolerability of extended-interval aminoglycoside administration in pediatric patients

Aminoglycosides are commonly used to treat serious Gram-negative infections in pediatric patients. An effort to improve the efficacy and tolerability of this antibiotic class has led to evaluation of extended-interval aminoglycoside administration (EIAA). EIAA is designed to achieve higher peak plasma aminoglycoside concentrations, with relatively undetectable trough concentrations, when compared with conventional aminoglycoside administration (CAA), and is therefore expected to be markedly effective and to reduce drug accumulation and prevent nephrotoxicity and ototoxicity. Clinical trials evaluating EIAA in neonates included patients with suspected Gram-negative infections requiring short courses of aminoglycoside therapy. Consequently, comparative efficacy of EIAA versus CAA could not be assessed. In addition, ototoxicity was often not assessed, and nephrotoxicity was virtually undetectable. Similarly, trials evaluating EIAA versus CAA in infants and children have not demonstrated a difference in outcomes. The use of EIAA in children with febrile neutropenia has been evaluated primarily with amikacin. The incidences of nephrotoxicity and ototoxicity were low, and were similar between EIAA and CAA. No deaths were reported in any of these studies; however, this could be related to the inclusion of patients with undocumented bacteremia. Further investigation of EIAA is necessary in patients with documented bacteremia, since plasma aminoglycoside concentrations were undetectable for most of the dosage interval in children with febrile neutropenia who were treated once daily. Overall, clinical studies suggest that EIAA has similar efficacy to, and no higher risk of toxicity than, CAA in neonates, infants, and children. A few evaluations have also demonstrated that EIAA is cost-effective in neonates and in children with febrile neutropenia. Future studies evaluating the efficacy and tolerability of EIAA in pediatric patients with documented systemic infections should be prospective, randomized, controlled trials with sample sizes sufficient to detect differences between administration methods. Further evaluations should also address the optimal dosage and cost-effectiveness of EIAA in infants and children.

Nonparametric population pharmacokinetic analysis of amikacin in neonates, infants, and children

The therapeutic and toxic effects of amikacin are known to depend on its concentration in plasma, but the pharmacokinetics of this drug in neonates, infants, and children and the influences of clinical and biological variables have been only partially assessed. Therapeutic drug monitoring data collected from 155 patients (49 neonates, 77 infants, and 29 children) receiving amikacin were analyzed by a nonparametric population-based approach, the nonparametric maximum-likelihood method. We assessed the effects of gestational and postnatal age, weight, Apgar score, and plasma creatinine and urea concentrations on pharmacokinetic parameters. There is no specific formulation of amikacin for neonates and infants. We therefore used an error model to account for errors due to dilution during preparation of the infusion. The covariates that reduced the variance of clearance from plasma and the volume of distribution by more than 10% were postnatal age (43 and 28%, respectively) and body weight (30.4 and 17.4%, respectively). The expected reduction of clearance was about 10% for the plasma creatinine concentration. The other covariates studied (Apgar scores, plasma urea concentration, gestational age, sex) were found to have little effect. Simulations showed that a smaller percentage of patients had a maximum concentration in plasma/MIC ratio greater than 8 with a regimen of 7.5 mg/kg of body weight twice daily than with a regimen of 15 mg/kg once a day for MICs of 1 to 8 mg/liter.

Once daily ceftriaxone and gentamicin for the treatment of febrile neutropenia

AIMS

To evaluate the pharmacokinetics of once daily (OD) gentamicin and its effectiveness as part of an OD regimen for the empirical treatment of febrile neutropenia in children with cancer.

SUBJECTS

59 children aged 6 months to 16 years (mean (SD) 5.7 (4) years) with febrile neutropenia (neutrophil count < 0.5 x 10(9)/l) after chemotherapy.

METHODS

Over one year, 113 febrile neutropenic episodes were treated empirically with an OD antibiotic regimen of ceftriaxone (80 mg/kg; maximum 4 g) and gentamicin (7 mg/kg; infused over 60 minutes, no maximum). The patients were assessed after 48 hours.

RESULTS

86 of the 113 episodes settled with the first line antibiotic regimen. In 29 episodes, blood cultures identified a causative bacterial pathogen; for 17 of these, the first line antibiotic regimen was adequate; in four episodes, although the episode settled, ceftriaxone was replaced by a more appropriate antibiotic and OD gentamicin was continued; in the remaining eight episodes, a glycopeptide antibiotic was deemed necessary. There was no failure of treatment in organisms sensitive to gentamicin, including Pseudomonas aeruginosa. In 27 episodes (24%), resolution was obtained by the empirical introduction of a second line regimen of ceftazidime and a glycopeptide antibiotic, and/or amphotericin. Gentamicin concentrations were measured in 110 episodes and they were all below the 24 hour line indicating that there was no need to change the dosing interval. In two episodes (2%), serum creatinine rose transiently by more than 50% of the baseline concentration. Although there was no vestibular toxicity, three of 30 children who underwent pure tone audiometry reported high frequency hearing loss in one ear.

CONCLUSION

OD gentamicin can be used safely and effectively to treat febrile neutropenia in children with cancer. When used for a short period (< 5 days), in children not receiving other nephrotoxic drugs and who have normal serum creatinine, serum gentamicin estimations are unnecessary.

Routine monitoring of gentamicin serum concentrations in pediatric patients with normal renal function is unnecessary

OBJECTIVE

Due to increasing demands for cost containment within the healthcare system, we evaluated the need for routine gentamicin concentrations (i.e., peak and trough with third dose).

DESIGN

Single-institution study performed concurrently with hospitalization.

SETTING

A 225-bed pediatric teaching hospital.

PARTICIPANTS

The study population consisted of 150 hospitalized pediatric patients (53% medicine, 47% surgical patients) from 3 months to 15 years old with normal serum creatinine.

OUTCOME MEASURES

If the administered dose produced diagnoses-appropriate peak concentrations of at least 4 micrograms/mL or 5 micrograms/mL in bacteremia/septicemia and at least 6 micrograms/mL or 8 micrograms/mL in patients with pneumonia if trough serum gentamicin concentrations were less than 2 micrograms/mL, if the patient was noted by the attending physician to be clinically responding as well as objectively having a decreased white blood cell count and was afebrile, and if there was not an increase of 0.5 mg/dL or more in serum creatinine during the course of therapy.

RESULTS

Patients received a mean dose of gentamicin 2.51 +/- 0.14 mg/kg i.v. q8h, which resulted in a mean peak concentration of 6.1 +/- 1.7 micrograms/mL (range 2.4-11.7) and a mean trough concentration of 0.5 +/- 0.3 microgram/mL (range 0.1-1.8). Peak and trough concentrations were at least 4 micrograms/mL and less than 2 micrograms/mL in 96% and 100% of patients, respectively. No patient required a dosage change due to lack of clinical response.

CONCLUSIONS

Our data do not support the routine monitoring of gentamicin concentrations in pediatric patients older than 3 months of age who are receiving appropriate standard doses of gentamicin and have normal renal function.

A closer look at vancomycin, teicoplanin, and antimicrobial resistance

The worldwide increase in the incidence of resistant Gram-positive infections has renewed interest in the glycopeptide class of antimicrobial agents. Two glycopeptides are available in many parts of the world--vancomycin and teicoplanin. These two agents appear to differ in several respects, including: potential for selecting microbial resistance, dosing convenience, safety, and efficacy in severe infection. Teicoplanin appears to have lower toxicity and greater convenience; however, its widespread acceptance has been plagued by concerns over antimicrobial resistance, efficacy, and appropriate dosing. A review of available studies suggests that teicoplanin, when dosed at 6 mg/kg/day, is better tolerated than vancomycin 15 mg/kg/q12h; however, at these doses, it appears to be somewhat less effective than vancomycin in serious Staphylococcus aureus infection, such as endocarditis. Although higher doses of teicoplanin, 12 mg/kg/day to 30 mg/kg/day, have been associated with efficacy comparable to that of vancomycin in serious S. aureus infections, such doses may eliminate some of the safety advantages conferred by lower teicoplanin doses. Teicoplanin has been associated with resistance among coagulase-negative staphylococci and the selection of resistance in S. aureus. There is some evidence that widespread use of teicoplanin might accelerate the development of S. aureus resistance to both teicoplanin and vancomycin. The selection of an appropriate glycopeptide in an individual patient should be based not only on convenience, but also on a determination of optimal efficacy, safety at an efficacious dose, and the potential for resistance.

A comparison of two amikacin dosing regimens in paediatric surgical patients

This investigation aimed to compare the efficacy and toxicity of two amikacin dosing regimens in seriously ill paediatric surgical patients. Children (0.6-12 years old) received amikacin intravenously either once daily (15 mg/kg, n = 27) or twice daily (7.5 mg/kg, n = 27). Concomitant medication was given as prescribed. Mean (SD) peak serum amikacin levels were significantly different (p < 0.05) between the once and twice daily groups (37.7 (6.9) mg/l and 19.5 (3.7) mg/l, respectively). Cumulative dose and duration of therapy were also significantly higher in the once-daily group. Regimen efficacy (favourable, unfavourable or indeterminate outcome) was assessed by patient temperatures, clinical improvement and white cell counts. Serum creatinine measurements and post-therapy, pure tone air conduction audiometry assessed nephro- and ototoxicity, respectively. No statistically significant differences were found between the groups in terms of outcome (18/24 and 22/25 patients in the once- and twice-daily groups had favourable outcomes; there were no unfavourable outcomes), nephrotoxicity (none of the patients assessed developed nephrotoxicity) or ototoxicity (2/20 and 5/20 patients, respectively, had mild high frequency hearing deficits which were predominantly unilateral and reversible). Although the regimens were similar in this study, other investigations will further clarify the optimal dosing approach in paediatric patients.

Fever and neutropenia in children with malignant disease

Treatment of episodes of fever and neutropenia in pediatric hematology-oncology patients includes hospitalization and administration of intravenous antibiotics until the patient is afebrile and no longer neutropenic. The present analysis characterizes retrospectively febrile episodes in neutropenic pediatric hematology-oncology patients with regard to frequency of documented infections, organisms associated with these infections, efficacy of a standardized antibiotic regimen, and safety of early antibiotic discontinuation under defined conditions. A total of 149 pediatric febrile neutropenic episodes were identified during a 4-year period between 1990 and 1994. These occurred in 47 male and 19 female patients, of a mean age of 7.6 years (range 0.5-15). The most frequent diagnoses were leukemia (41% of patients), lymphoma (21%), rhabdomyosarcoma (7%), soft tissue sarcoma (5%), Ewing's sarcoma (5%), and osteosarcoma (4%). Infection was certain in 36% of febrile episodes, probable in 14%, and not determined in 50%. Patients with severe neutropenia (absolute neutrophil count < 100) had a slightly, although not significantly higher incidence of documented and probable infection (57%). Patients with solid tumor had documented infection in 40% of their febrile episodes, and the detection rate in the children with leukemia was 31% (P < .20) Blood cultures were positive in 21 (14%) of 149 episodes. Staphylococci (both coagulase-negative and coagulase-positive strains) and Pseudomonas were the organisms most frequently isolated (six episodes each). Mouth and throat (11), lungs (10), and skin (10) were the next most frequent sites of localized infection. Initial treatment consisted of piperacillin and amikacin or of vancomycin and amikacin when the source of fever was thought to be an infected central line catheter, with addition of amphotericin B by the seventh day of treatment when fever with neutropenia persisted or upon clinical suspicion of underlying fungal infection. There was a single fatality, of a patient with Burkitt's lymphoma. Antibiotics were discontinued when initial blood cultures had no growth after at least 48 hours and no source of infection was found, the blood count was improving, and if the patient became afebrile and clinically well. No patient needed readmission during the fortnight that followed discontinuation of antimicrobial therapy. Patients with negative blood cultures under defined conditions, as described above, could safely be discharged early, thus shortening the duration of intravenous antibiotic therapy and hospital stay.

[Clinical, pharmacokinetic and therapeutic study of amikacin with single daily dose and in combination in neutropenic children with fever]

BACKGROUND

The efficacy of single daily dose of amikacin has been recently demonstrated in neutropenic children with fever.

POPULATION AND METHODS

Eighteen children aged 1 to 15 years were included in the study. All patients were febrile and granulocytopenic and had indwelling intravenous catheter. Amikacin was administered as a 30-minute intravenous infusion once daily (20 mg/kg on day 1, then 15 mg/kg) for 3 to 30 days; the patients received amikacin in combination with piperacillin and vancomycin. Serum levels of amikacin were measured on days 1, 3, 6 and 10, and 30 min, 60 min and 180 min after the end of the infusion.

RESULTS

All patients responded favourably to the antibiotic therapy. Sixty-two kinetics were performed: peak amikacin concentrations measured (30 min after 30-min infusion) on day 1 averaged 43.7 micrograms/mL (+/- 13.8). A significant increase in peak serum concentrations was observed during the treatment (day 3 vs day 10) without change in the trough serum concentrations. The volumes of distribution were considerably important in these granulocytopenic children and there was a large inter and intra-patient variability; the elimination half-life of the amikacin was short (1.45 h). There was no significant nephrotoxicity in any patient.

CONCLUSION

The use of single daily dose amikacin in combination with a broad spectrum beta-lactam antibiotic and vancomycin was efficient and safe in febrile granulocytopenic children. The simulation of the amikacin behaviour in the deep compartment should be evaluated; in fact, it might reflect better accumulation of the drug than serum concentrations.