Empirical antimicrobial therapy with a single daily dose of ceftriaxone plus amikacin in febrile granulocytopenic patients: a pilot study

Once-Daily Aminoglycosides: A Meta-Analysis of Nonneutropenic and Neutropenic Adults

Objective:

To compare the efficacy, nephrotoxicity, and ototoxicity of once-daily dosing of aminoglycosides versus conventional dosing.

Design:

Meta-analysis of 14 randomized trials identified through a MEDLINE search (January 1965-May 1996).

Patients:

Neutropenic and nonneutropenic adults.

Interventions:

Patients were randomly selected to receive an aminoglycoside once daily or in multiple daily doses.

Measurements and Main Outcomes:

The outcomes considered were clinical cure, bacteriologic cure, nephrotoxicity, auditory toxicity, and vestibular toxicity. The data were analyzed in the following subgroups: (1) all trials, (2) nonneutropenic patients, (3) neutropenic patients, and (4) patients with undefined neutrophil status. For all trials the pooled risk ratio was 1.268 (95% CI 0.828 to 1.939) for clinical cure, and was 1.390 (95% CI 1.350 to 1.392) for bacteriologic cure. Nephrotoxicity had a pooled risk ratio of 0.765 (95% CI 0.468 to 1.252), that for auditory toxicity was 1.117 (95% CI 0.151 to 5.636), and that for vestibular toxicity was 1.155 (95% CI 0.221 to 6.039). Analysis of the subgroups, including a separate analysis of neutropenic patients, demonstrated similar results.

Conclusions:

When all trials were considered, once-daily administration of aminoglycosides had similar efficacy and no increase in nephrotoxicity or ototoxicity compared with conventional aminoglycoside dosing.

Extended-interval aminoglycoside therapy for adult patients with febrile neutropenia: a systematic review

BACKGROUND

Although the efficacy and toxicity of extended-interval (once-daily) aminoglycoside regimens is well established for immunocompetent patients, there is clinical concern about using this regimen for patients with neutropenia.

OBJECTIVE

To summarize and evaluate the literature reporting the clinical efficacy and safety of extended-interval aminoglycosides therapy in adults with febrile neutropenia.

METHODS

A literature search was conducted within PubMed, Embase, and the Cochrane Database of Systematic Reviews to identify studies assessing the use of extended-interval aminoglycosides for treating febrile neutropenia in adults. Articles were categorized by quality of evidence, according to the rating scale of the US Preventive Services Task Force.

RESULTS

TEN ARTICLES WERE IDENTIFIED: 5 with level I evidence, 1 with level II-2 evidence, and 4 with level III evidence. Review of the 5 studies with level I evidence (all open-label randomized controlled trials), which compared extended-interval dosing with multiple-daily dosing strategies, revealed no evidence to suggest superiority of one regimen over the other in terms of clinical outcomes. In the study with level II-2 evidence (a prospective comparative trial), the response rate was better in the extended-interval group than in the standard-therapy group. Two of the studies with level III evidence (both prospective noncomparative trials) also had acceptable response rates to extended-interval aminoglycoside therapy, with minimal associated nephrotoxicity. In this review, no major differences in rates of nephrotoxicity or ototoxicity were seen between the 2 dosing regimens.

CONCLUSIONS

The use of extended-interval dosing for aminoglycosides, in combination with other recommended antibiotic therapy, is an effective and safe management strategy for immunocompromised patients with febrile neutropenia. In this population, the clinical efficacy and safety of extended-interval dosing does not appear to differ from those of standard dosing. Whether routine or selective pharmacokinetic monitoring in this patient subpopulation leads to improvements in outcomes is yet to be determined.

Gentamicin for the practicing urologist: review of efficacy, single daily dosing and "switch" therapy

PURPOSE

We review the literature on gentamicin, including single daily dosing and "switch" therapy.

MATERIALS AND METHODS

We used MEDLINE to search the literature from 1966 to June 1997, and then manually searched bibliographies to identify studies that our initial search might have missed.

RESULTS

Gentamicin has attractive characteristics, including wide spectrum, infrequent resistance, economy and familiarity. Although limited by well known toxicities, gentamicin remains a drug of choice for serious Gram-negative infections. Dosing strategies, such as single daily dosing and switch therapy, have renewed enthusiasm for this time-honored drug.

CONCLUSIONS

Gentamicin remains a valuable drug in urology. Once daily dosing and switch therapy offer the potential to increase effectiveness and convenience while decreasing toxicity and costs.

Once daily ceftriaxone plus amikacin vs. three times daily ceftazidime plus amikacin for treatment of febrile neutropenic children with cancer. Writing Committee for the International Collaboration on Antimicrobial Treatment of Febrile Neutropenia in Children

BACKGROUND

The combination of ceftazidime plus aminoglycoside is widely used for the treatment of febrile neutropenic patients but requires multiple daily administration. Because the frequency of Pseudomonas aeruginosa is low in many centers, there is a rationale to test other antibiotic regimens that provide appropriate antibacterial coverage with the advantage of reduced dosing frequency, such as once daily ceftriaxone plus amikacin.

METHODS

Febrile neutropenic children with leukemia, lymphoma or solid tumors after chemotherapy were included in an open, prospective, randomized, multinational study comparing once daily ceftriaxone plus amikacin vs. 8-hourly ceftazidime and amikacin. The response to antimicrobial therapy was defined as complete response, improvement or failure. Assessment of adverse events was supplemented by specific definitions of nephrotoxicity, ototoxicity, hepatotoxicity and hypokalemia. Costs were estimated from published values of acquisition costs, delivery costs and hospitalization costs.

RESULTS

Efficacy was evaluable in 364 of 468 episodes in 265 children. Response rates in ceftriaxone and amikacin vs. ceftazidime and amikacin-treated episodes were 119 of 181 (66%) vs. 121 of 183 (66%), 7 of 181 (4%) vs. 9 of 183 (5%) and 55 of 181 (30%) vs. 53 of 181 (29%) for complete response, improvement and failure, respectively. Safety profiles were similar with both treatment regimens. The acquisition and administration costs were lower for the ceftriaxone and amikacin regimen.

CONCLUSIONS

A once daily regimen of ceftriaxone and amikacin is as safe and clinically effective as that of three times daily ceftazidime and amikacin for the treatment of febrile neutropenic children with cancer and is more cost-effective. The once daily regimen of ceftriaxone and amikacin is suitable for outpatient treatment.

Once daily antibiotic regimen in paediatric oncology

The feasibility and efficacy of a once daily antibiotic regimen were assessed in children with malignant tumours. Over a 44 month period, 296 febrile episodes were treated with a regimen of once daily ceftriaxone-amikacin (and teicoplanin or vancomycin if the patient had a central line). The treatment was successful in 272 (92%) episodes without modification of the antibiotic regimen, and only one patient died of uncontrolled sepsis. A once daily antibiotic regimen is therefore feasible and worthwhile in the treatment of febrile episodes in children with cancer.

Nephrotoxicity of low doses of tobramycin in rats: effect of the time of administration

The circadian and the circannual variations of the nephrotoxicity of tobramycin were studied in female Sprague-Dawley rats. Animals were maintained on a light-dark period of 14/10 hrs (light on: 06h00 to 20h00). They were injected once daily for 4 and 10 days with saline or tobramycin at a dose of 40 mg/kg/day i.p. at either 08h00, 14h00, 20h00 and 02h00, in April 1991, July 91, October 91, January 92. In April 91, tobramycin injected at 14h00 during 10 days induced a significant increase of [3H]-thymidine incorporation into DNA of renal cortex as compared to other groups (p < 0.01): toxicity was highest at 14h00 and lowest at 02h00. No temporal change was observed in the renal cortical accumulation of tobramycin, and in serum creatinine after the 4 or 10 days of treatment. In experiments done in April, July and October 1991 and in January 1992, no circannual variation was found in tobramycin cortical levels but peaks of toxicity were observed at 02h00 in April and October 1991 and at 14h00 in July 1991 and January 1992. There was no linear correlation between the toxicity and the tobramycin accumulation in the renal cortex (r = 0.21). The data suggest that the circadian changes in tobramycin toxicity are due to temporal changes in the susceptibility of renal cells to tobramycin.

Pharmacodynamic effects of antibiotics. Studies on bacterial morphology, initial killing, postantibiotic effect and effective regrowth time

Pharmacodynamics of antibiotics deals with time course of drug activity and mechanisms of action of drugs on bacteria. In this thesis pharmacodynamic parameters have been studied after brief exposure of gram-positive bacteria to daptomycin, imipenem or vancomycin and after short exposure of gram-negative bacteria to amikacin, ampicillin, aztreonam, cefepime, cefotaxime, ceftazidime, ceftriaxone, cefuroxime, imipenem, mecillinam, or piperacillin. The studies have been focused on morphological alterations, initial killing, postantibiotic effect (PAE) and effective regrowth time (ERT) and a method, based on bioluminescence assay of intracellular ATP has been used. The basic principle behind this technique is that ATP in living cells is present in a relatively constant amount, and hence affords a measure of the number of microbial cells. The PAE describes the delayed regrowth of bacteria after brief exposure to antibiotics. The number of cells measured after this antibiotic exposure describes the initial killing and is also the start value for calculating the PAE. PAEs of 2-3 h were obtained by bioluminescence for gram-positive bacteria exposed to imipenem or vancomycin. This is in agreement with results obtained by viable count and is probably due to similar weak initial decrease in cell density when assayed by both methods. Long (greater than 3 h) concentration dependent PAEs and moderate (less than or equal to 1 log10) initial decrease in intracellular ATP were in general seen for gram-positive bacteria exposed to daptomycin and for gram-negative bacteria exposed to imipenem or amikacin when assayed by bioluminescence. These very long PAEs and rather weak initial killing have to be compared with the shorter PAEs and stronger initial killing reported by us and others using viable count. Furthermore, this study showed that there was a relatively good concordance between microscopy and bioluminescence, which are direct methods, in determining the initial killing and PAE of imipenem on Escherichia coli. The ERT, defined as the time for bacterial density to increase 1 log10 from the pre-exposure inoculum, was independent of the method used for measuring regrowth of E. coli after brief exposure to imipenem. The combination of mecillinam with ampicillin, aztreonam, ceftazidime or piperacillin and the combination of amikacin with ceftazidime, ceftriaxone or piperacillin induced longer PAEs on gram-negative bacteria than the sum of PAEs of the individual antibiotics. A strong initial killing in combination with a long PAE cause a long ERT and may allow the antibiotic concentration to stay below MIC during long periods of time without any regrowth. This may, in clinical practice, have implications for long dosing intervals.