The pharmacokinetics of ceftriaxone and cefotaxime in cirrhotic patients with ascites

Physiologically-Based Pharmacokinetic Modeling and Dosing Optimization of Cefotaxime in Preterm and Term Neonates

BACKGROUND

Cefotaxime is commonly used in treating bacterial infections in neonates. To characterize the pharmacokinetic process in neonates and evaluate different recommended dosing schedules of cefotaxime, a physiologically-based pharmacokinetic (PBPK) model of cefotaxime was established in adults and scaled to neonates.

METHODS

A whole-body PBPK model was built in PK-SIM® software. Three elimination pathways are composed of enzymatic metabolism in the liver, passive filtration through glomerulus, and active tubular secretion mediated by renal transporters. The ontogeny information was applied to account for age-related changes in cefotaxime pharmacokinetics. The established models were verified with realistic clinical data in adults and pediatric populations. Simulations in neonates were conducted and 100 % of the dosing interval where the unbound concentration in plasma was above the minimum inhibitory concentration (fT>MIC) was selected as the target index for dosing regimen evaluation.

RESULTS

The developed PBPK models successfully described the pharmacokinetic process of cefotaxime in adults and were scaled to the pediatric population. Good verification results were achieved in both adults' and neonates' PBPK models, indicating a good predictive performance. The optimal dosage regimen of cefotaxime was proposed according to the postnatal age (PNA) and gestational age (GA) of neonates. For preterm neonates (GA < 36 weeks), dosages of 25 mg/kg every 8 h in PNA 0-6 days and 25 mg/kg every 6 h in PNA 7-28 days were suggested. For term neonates (GA ≥ 36 weeks), dosages of 33 mg/kg every 8 h in PNA 0-6 days and 33 mg/kg every 6 h in PNA 7-28 days were recommended.

CONCLUSIONS

Our study may provide useful experience in practicing PBPK model-informed precision dosing in the pediatric population.

Bacterial growth and ceftriaxone activity in individual ascitic fluids in an in vitro model of spontaneous bacterial peritonitis

Introduction: The environment of the infection site affects bacterial growth and antibiotic activity. When bacterial growth and antibiotic activity are studied in body fluids, samples of multiple subjects are usually pooled, averaging out potentially relevant differences in composition. The ascitic fluid (AF) environment is frequently associated with spontaneous bacterial peritonitis (SBP) in cirrhotic patients. In this study, bacterial growth and ceftriaxone activity were evaluated in individual AF using an in vitro model of SBP, reflecting the environment and pharmacokinetics at the infection site.

Methods: AF was obtained from nine cirrhotic patients with non-infected ascites. Growth of nine bacterial strains (three Escherichia coli, four Staphylococcus aureus, one Enterococcus faecalis, and one Klebsiella pneumoniae) in individual AF was assessed and correlated with biomarkers including potential risk factors for SBP. Ceftriaxone time-kill experiments, in which the pharmacokinetic profile observed in AF following a 1 g intravenous infusion was replicated, were performed with two E. coli and two S. aureus isolates with minimum inhibitory concentrations around the ceftriaxone resistance breakpoint.

Results: Significant correlations were found between bacterial growth and AF levels of protein (Spearman’s rank correlation coefficient ρ = −0.35), albumin (ρ = −0.31), and complement C3c (ρ = −0.28), and serum levels of bilirubin (ρ = 0.39) and aspartate aminotransferase (ρ = 0.25). Ceftriaxone was active in AF, even against resistant isolates, generally resulting in ≥2 log reductions in bacterial count within 24 h.

Conclusion: Ascites patients may be predisposed to or protected against SBP based on the antimicrobial capacity of their AF. Ceftriaxone at clinical AF concentrations is active in the AF environment.

Evaluation of the current guidelines for antibacterial therapy strategies in patients with cirrhosis or liver failure

BACKGROUND

Bacterial infections are common complications in patients with cirrhosis or liver failure and are correlated with high mortality. Clinical practice guideline (CPG) is a reference used to help clinicians make decisions. This systematic appraisal aimed to evaluate the methodological quality and summarize the recommendations of reported CPGs in these patients.

METHODS

We systematically searched CPGs published from 2008 to 2019. The methodological quality of the included CPGs was assessed using the AGREE II instrument. We extracted and compared recommendations for prophylactic and empirical treatment strategies.

RESULTS

Fourteen CPGs with a median overall score of 56.3% were included. The highest domain score was Clarity of Presentation (domain 4, 85.4%), and the lowest was for Stakeholder Involvement (domain 2, 31.3%). Three CPGs had an overall score above 80%, and 6 CPGs had a score above 90% in domain 4. Prophylaxis should be strictly limited to patients with varicose bleeding, low ascites protein levels and a history of spontaneous bacterial peritonitis. Fluoroquinolones (norfloxacin and ciprofloxacin), third-generation cephalosporins (G3) (ceftriaxone and cefotaxime) and trimethoprim-sulfamethoxazole (SXT) are recommended for preventing infections in patients with cirrhosis or liver failure. G3, β-lactam/β-lactamase inhibitor combinations (BLBLIs) and carbapenems are recommended as the first choice in empirical treatment according to local epidemiology of bacterial resistance.

CONCLUSIONS

The methodological quality of CPGs focused on patients with cirrhosis or liver failure evaluated by the AGREE II instrument is generally poor. Three CPGs that were considered applicable without modification and 6 CPGs that scored above 90% in domain 4 should also be paid more attention to by healthcare practitioners. Regarding recommendations, norfloxacin, ciprofloxacin, ceftriaxone, cefotaxime, and SXT are recommended for prophylactic treatment appropriately. G3, BLBLIs, and carbapenems are recommended for use in empirical treatment strategies.

Antibiotics and Liver Cirrhosis: What the Physicians Need to Know

The liver is the primary site of drug metabolism, which can be altered by a variety of diseases affecting the liver parenchyma, especially in patients with liver cirrhosis. The use of antibiotics in patients with cirrhosis is usually a matter of concern for physicians, given the lack of practical knowledge for drug choice and eventual dose adjustments in several clinical scenarios. The aim of the current narrative review is to report, as broadly as possible, basic, and practical knowledge that any physician should have when approaching a patient with liver cirrhosis and an ongoing infection to efficiently choose the best antibiotic therapy.

Tolerability, Safety, Pharmacokinetics and Drug Interaction of Cefotaxime Sodium-Tazobactam Sodium Injection (6:1) Following Single and Multiple Intravenous Doses in Chinese Healthy Subjects

Purpose

To evaluate the tolerability, safety, pharmacokinetics and drug interaction of cefotaxime sodium-tazobactam sodium injection (6:1) in Chinese healthy subjects. The results of the safety and pharmacokinetic studies supported further clinical trials.

Method

A randomized, single-blind, ascending dose, placebo-controlled, single-center study was conducted. Sixty healthy subjects (38 males, 22 females) participated in this study. For the single-dose part, 0.47, 1.17, 2.34, 3.51, and 4.68 g of cefotaxime sodium-tazobactam sodium injection (6:1) was administered. For the multiple-dose part, the subjects were administered 2.34 and 3.51 g cefotaxime sodium-tazobactam sodium injection (6:1) three times a day for 7 consecutive days. For the drug interaction part, the subjects received 2.0 g cefotaxime sodium and 0.34 g tazobactam sodium alone and in combination.

Results

Most adverse events and adverse drug reactions were mild. Moderate rash was considered a serious adverse event because of prolongation of hospitalization. The main pharmacokinetic parameters of cefotaxime and tazobactam had no significance difference between the 1.17, 2.34, and 3.51 g dose cohorts and between genders. There was no difference in trough concentrations on days 6, 7, and 8. The R _{C max} and R _AUC were (0.921 ± 0.070) and (0.877 ± 0.057) for cefotaxime, and (0.913 ± 0.046) and (0.853 ± 0.060) for tazobactam, respectively. Following the administration of cefotaxime and tazobactam alone and in combination, the 90% confidence intervals of the geometric mean ratios for C _max and AUC were within the predetermined range of 80-125%. In the single-dose part, the renal cumulative excretion ratios were (51.7 ± 6.2)% for cefotaxime, and (84.3 ± 8.1)% for tazobactam. There was no significant difference in the maximum excretion rates and cumulative excretion ratios for cefotaxime and tazobactam, alone or in combination.

Conclusions

Cefotaxime sodium-tazobactam sodium injection (6:1) was well-tolerated at doses of 0.47 to 4.68 g. The pharmacokinetics of cefotaxime and tazobactam were reported as linear over a dose range of 1.17-3.51 g. Cefotaxime was partially excreted via urine, whereas tazobactam was mainly excreted via urine. There was no significant accumulation after administration over 7 consecutive days. The pharmacokinetics and excretion of cefotaxime and tazobactam were not affected by the co-administration of cefotaxime-tazobactam.

Clinical characteristics and outcomes of spontaneous bacterial peritonitis caused by Enterobacter species versus Escherichia coli: a matched case-control study

Background

Enterobacter species are important nosocomial pathogens, and there is growing concern about their ability to develop resistance during antimicrobial therapy. However, few data are available on the clinical characteristics and outcomes of Enterobacter spontaneous bacterial peritonitis (SBP).

Methods

We retrospectively identified all patients with SBP caused by Enterobacter species admitted to a tertiary care hospital between January 1997 and December 2013. Each case was age- and sex-matched with four patients with Escherichia coli SBP.

Results

A total of 32 cases with Enterobacter SBP and 128 controls with E. coli SBP were included. Twenty-one (65.6 %) cases and 111 (86.7 %) controls had Child-Pugh class C (P = 0.006). Cases were significantly more likely to have hepatocellular carcinoma (65.6 % vs. 37.5 %, P = 0.004) and upper gastrointestinal bleeding (28.1 % vs. 9.4 %, P = 0.005). The initial response to empirical therapy (81.3 % vs. 81.2 %, P = 0.995) and the 30-day mortality (37.5 % vs. 28.9 %, P = 0.35) were not significantly different between the groups. Drug resistance emerged in one case and in no controls (4.3 % [1/23] vs. 0 % [0/98], P = 0.19).

Conclusions

Compared with E. coli SBP, patients with Enterobacter SBP more frequently had hepatocellular carcinoma and upper gastrointestinal bleeding, yet clinical outcomes were comparable. Development of resistance during third-generation cephalosporin therapy was infrequent in patients with Enterobacter SBP.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1595-y) contains supplementary material, which is available to authorized users.

Drug-induced liver injury associated with high-dose ceftriaxone: a retrospective cohort study adjusted for the propensity score

PURPOSE

Ceftriaxone has been recognized as a well-tolerated drug; however, in some instances, liver dysfunction occurs after using high-dose ceftriaxone. We aimed to assess the incidence of liver injury due to high-dose ceftriaxone and to determine whether there is a dose-dependent risk of liver injury with this drug.

METHODS

We conducted a retrospective cohort study of hospitalized adult patients treated with ceftriaxone at a tertiary care hospital from January 2012 to October 2013. We collected demographic and clinical data by reviewing their medical records. The incidence of liver injury based on biochemical criteria, defined as a primary outcome, was compared between patients treated with high-dose ceftriaxone (4 g/day) and those treated with a normal dose of ceftriaxone (2 g/day) for ≥5 consecutive days. A propensity score for the use of high-dose ceftriaxone was calculated from five factors.

RESULTS

We identified 37 patients treated with high-dose ceftriaxone and 434 patients treated with a normal dose of ceftriaxone. Among these 471 patients, 15 patients (3.2 %) experienced liver injury, of whom six patients (6/37, 16.2 %) had received high-dose ceftriaxone and nine patients (9/434, 2.1 %) had received normal doses of ceftriaxone. In the multivariate analysis adjusted for the propensity score, high-dose ceftriaxone was independently associated with liver injury (odds ratio, 7.23; 95 % confidence interval, 2.01-26.0).

CONCLUSIONS

The present study revealed that high-dose ceftriaxone was associated with a significantly higher incidence of liver injury compared with the normal-dose regimen. Therefore, clinicians should carefully observe for signs of liver injury after high-dose ceftriaxone use.

Role of enterohepatic recirculation in drug disposition: cooperation and complications

Enterohepatic recirculation (EHC) concerns many physiological processes and notably affects pharmacokinetic parameters such as plasma half-life and AUC as well as estimates of bioavailability of drugs. Also, EHC plays a detrimental role as the compounds/drugs are allowed to recycle. An in-depth comprehension of this phenomenon and its consequences on the pharmacological effects of affected drugs is important and decisive in the design and development of new candidate drugs. EHC of a compound/drug occurs by biliary excretion and intestinal reabsorption, sometimes with hepatic conjugation and intestinal deconjugation. EHC leads to prolonged elimination half-life of the drugs, altered pharmacokinetics and pharmacodynamics. Study of the EHC of any drug is complicated due to unavailability of the apposite model, sophisticated procedures and ethical concerns. Different in vitro and in vivo methods for studies in experimental animals and humans have been devised, each having its own merits and demerits. Involvement of the different transporters in biliary excretion, intra- and inter-species, pathological and biochemical variabilities obscure the study of the phenomenon. Modeling of drugs undergoing EHC has always been intricate and exigent models have been exploited to interpret the pharmacokinetic profiles of drugs witnessing multiple peaks due to EHC. Here, we critically appraise the mechanisms of bile formation, factors affecting biliary drug elimination, methods to estimate biliary excretion of drugs, EHC, multiple peak phenomenon and its modeling.

Evolving epidemiology and antimicrobial resistance in spontaneous bacterial peritonitis: a two-year observational study

BACKGROUND

Current recommendations for empirical antimicrobial therapy in spontaneous bacterial peritonitis (SBP) are based on quite old trials. Since microbial epidemiology and the management of patients have changed, whether these recommendations are still appropriate must be confirmed.

METHODS

An observational study that exhaustively collected the clinical and biological data associated with positive ascitic fluid cultures was conducted in four French university hospitals in 2010-2011.

RESULTS

Two hundred and sixty-eight documented positive cultures were observed in 190 cirrhotic patients (median age 61.5 years, 58.5% Child score C). Of these, 57 were classified as confirmed SBP and 140 as confirmed bacterascites. The predominant flora was Gram-positive cocci, whatever the situation (SBP, bacterascites, nosocomial/health-care related or not). Enteroccocci (27.7% E. faecium) were isolated in 24% of the episodes, and in 48% from patients receiving quinolone prophylaxis. E. coli were susceptible to amoxicillin-clavulanate and to third-generation cephalosporins in 62.5% and 89.5% of cases, respectively. No single antibiotic allowed antimicrobial coverage of more than 60%. Only combinations such as amoxicillin + third-generation cephalosporin or cotrimoxazole allowed coverage close to 75-80% in non-nosocomial episodes. Combinations based on broader spectrum antibiotics should be considered for empirical therapy of nosocomial infections.

CONCLUSIONS

Our study confirmed the changing spectrum of pathogens in SBP and bacterascites, and the need for more complex antibiotic strategies than those previously recommended. Our findings also underline the need for new clinical trials conducted in the current epidemiological context.

Management of antimicrobial use in the intensive care unit

Critically ill patients admitted to the intensive care unit (ICU) are frequently treated with antimicrobials. The appropriate and judicious use of antimicrobial treatment in the ICU setting is a constant clinical challenge for healthcare staff due to the appearance and spread of new multiresistant pathogens and the need to update knowledge of factors involved in the selection of multiresistance and in the patient's clinical response. In order to optimize the efficacy of empirical antibacterial treatments and to reduce the selection of multiresistant pathogens, different strategies have been advocated, including de-escalation therapy and pre-emptive therapy as well as measurement of pharmacokinetic and pharmacodynamic (pK/pD) parameters for proper dosing adjustment. Although the theoretical arguments of all these strategies are very attractive, evidence of their effectiveness is scarce. The identification of the concentration-dependent and time-dependent activity pattern of antimicrobials allow the classification of drugs into three groups, each group with its own pK/pD characteristics, which are the basis for the identification of new forms of administration of antimicrobials to optimize their efficacy (single dose, loading dose, continuous infusion) and to decrease toxicity. The appearance of new multiresistant pathogens, such as imipenem-resistant Pseudomonas aeruginosa and/or Acinetobacter baumannii, carbapenem-resistant Gram-negative bacteria harbouring carbapenemases, and vancomycin-resistant Enterococcus spp., has determined the use of new antibacterials, the reintroduction of other drugs that have been removed in the past due to toxicity or the use of combinations with in vitro synergy. Finally, pharmacoeconomic aspects should be considered for the choice of appropriate antimicrobials in the care of critically ill patients.

Usefulness of reagent strips for checking cure in spontaneous bacterial peritonitis after short-course treatment

BACKGROUND

The usefulness of reagent strips to check cure of spontaneous bacterial peritonitis have not been evaluated to date.

AIM

To assess the usefulness of ascitic fluid analysis by means of reagent strips to check cure after a 5-day antibiotic course.

METHODS

We prospectively included all cirrhotic patients diagnosed with spontaneous bacterial peritonitis. On day 5, conventional and reagent strip ascitic fluid analyses were performed.

RESULTS

Fifty-three episodes of spontaneous bacterial peritonitis in 51 cirrhotic patients were included. Five patients died before the fifth day and in two patients, the control paracentesis yielded no ascitic fluid. In nine out of 46 cases (19.6%), spontaneous bacterial peritonitis had not resolved by day 5. In 32 out of 33 cases in which the ascitic fluid polymorphonuclear count was <250/microL at day five, the reagent strips was negative. The negative predictive value of the reagent strip at fifth day was 97% and the LR- 0.13.

CONCLUSIONS

Almost 20% of episodes of spontaneous bacterial peritonitis do not resolve with a short-course of antibiotic treatment. In view of the high negative predictive value and low likelihood ratio for a negative test, reagent strips analysis may be an alternative to conventional cytology if a 5-day antibiotic therapy is planned.

Pharmacokinetics/pharmacodynamics of antibacterials in the Intensive Care Unit: setting appropriate dosing regimens

Patients admitted to Intensive Care Units (ICUs) are at very high risk of developing severe nosocomial infections. Consequently, antimicrobials are among the most important and commonly prescribed drugs in the management of these patients. Critically ill patients in ICUs include representatives of all age groups with a range of organ dysfunction related to severe acute illness that may complicate long-term illness. The range of organ dysfunction, together with drug interactions and other therapeutic interventions (e.g. haemodynamically active drugs and continuous renal replacement therapies), may strongly impact on antimicrobial pharmacokinetics in critically ill patients. In the last decade, it has become apparent that the intrinsic pharmacokinetic (PK) and pharmacodynamic (PD) properties are the major determinants of in vivo efficacy of antimicrobial agents. PK/PD parameters are essential in facilitating the translation of microbiological activity into clinical situations, ensuring a successful outcome. In this review, we analyse the typical patterns of antimicrobial activity and the corresponding PK/PD parameters, with a special focus on a PK/PD dosing approach of the antimicrobial agent classes commonly utilised in the ICU setting.

Bacterial DNA in patients with cirrhosis and noninfected ascites mimics the soluble immune response established in patients with spontaneous bacterial peritonitis

Bacterial infections and severity of associated inflammatory reaction influence prognosis in patients with advanced cirrhosis. We compared the innate immune response to bacterial DNA (bactDNA) translocation with that caused by viable bacteria translocation in patients with spontaneous bacterial peritonitis and the relationship between the cytokine response and serum levels of bactDNA. The bactDNA translocation was investigated in 226 patients with cirrhosis and noninfected ascites, 22 patients with spontaneous bacterial peritonitis, and 10 patients with ascites receiving continuous norfloxacin. Serum and ascitic fluid tumor necrosis factor alpha, interferon-gamma, interleukin-12, and nitric oxide metabolites were measured via enzyme-linked immunosorbent assay. Bacterial genomic identifications were made via amplification and sequencing of the 16S ribosomal RNA gene and digital quantization with DNA Lab-on-chips. The bactDNA was present in 77 noninfected patients (34%) and in all cases of spontaneous bacterial peritonitis, even in those with culture-negative ascitic fluid. No patient receiving norfloxacin showed bactDNA translocation. Levels of all cytokines were similar in patients with bactDNA translocation or spontaneous bacterial peritonitis and significantly higher than in patients without bactDNA or in those receiving norfloxacin. Serum bactDNA concentration paralleled levels of all cytokines and nitric oxide in a series of patients with bactDNA translocation or spontaneous bacterial peritonitis followed during 72 hours. Antibiotic treatment in the series of patients with spontaneous bacterial peritonitis did not abrogate bactDNA translocation in the short term.

CONCLUSION

bactDNA translocation-associated cytokine response is indistinguishable from that in patients with spontaneous bacterial peritonitis and is dependent on bactDNA concentration. Norfloxacin abrogates bactDNA translocation and cytokine response.

Influence of E. coli lipopolysaccharide induced fever on the plasma kinetics of cefepime in cross-bred calves

The pharmacokinetic behavior of cefepime was studied in healthy and febrile cross-bred calves after single intravenous administration (10 mg/kg). The fever was induced with E. coli lipopolysaccharide (1 microg/kg, IV). The drug concentration in plasma was detected by microbiological assay method using E. coli (MTCC 739) test organism. Pharmacokinetic analysis of disposition data indicated that intravenous administration data were best described by 2 compartment open model. At 1 min the concentration of cefepime in healthy and febrile animals were 55.3 +/- 0.54 microg/ml and 50.0 +/- 0.48 microg/ml, respectively and drug was detected up to 12 h. The elimination half-life of cefepime was increased from 1.26 +/- 0.01 h in healthy animals to 1.62 +/- 0.09 h in febrile animals. Drug distribution was altered by fever as febrile animals showed volume of distribution (0.27 +/- 0.02 L/kg) higher than normal animal (0.19 +/- 0.01 L/kg). Total body clearances in healthy and febrile animals were 104.4 +/- 2.70 and 114.2 +/- 1.20 ml/kg/h, respectively. To maintain minimum therapeutic concentration of 1 mug/ml, a satisfactory dosage regimen of cefepime in healthy and febrile cross-bred calves would be 15.5 mg/kg and 8.2 mg/kg body weight, respectively, to be repeated at 8 h intervals. The T>MIC values (8 h) of cefepime suggested that this agent is clinically effective in the treatment of various infections.

Antimicrobial therapy in critically ill patients: a review of pathophysiological conditions responsible for altered disposition and pharmacokinetic variability

Antimicrobials are among the most important and commonly prescribed drugs in the management of critically ill patients. Selecting the appropriate antimicrobial at the commencement of therapy, both in terms of spectrum of activity and dose and frequency of administration according to concentration or time dependency, is mandatory in this setting. Despite appropriate standard dosage regimens, failure of the antimicrobial treatment may occur because of the inability of the antimicrobial to achieve adequate concentrations at the infection site through alterations in its pharmacokinetics due to underlying pathophysiological conditions. According to the intrinsic chemicophysical properties of antimicrobials, hydrophilic antimicrobials (beta-lactams, aminoglycosides, glycopeptides) have to be considered at much higher risk of inter- and intraindividual pharmacokinetic variations than lipophilic antimicrobials (macrolides, fluoroquinolones, tetracyclines, chloramphenicol, rifampicin [rifampin]) in critically ill patients, with significant frequent fluctuations of plasma concentrations that may require significant dosage adjustments. For example, underexposure may occur because of increased volume of distribution (as a result of oedema in sepsis and trauma, pleural effusion, ascites, mediastinitis, fluid therapy or indwelling post-surgical drainage) and/or enhanced renal clearance (as a result of burns, drug abuse, hyperdynamic conditions during sepsis, acute leukaemia or use of haemodynamically active drugs). On the other hand, overexposure may occur because of a drop in renal clearance caused by renal impairment. Care with all these factors whenever choosing an antimicrobial may substantially improve the outcome of antimicrobial therapy in critically ill patients. However, since these situations may often coexist in the same patient and pharmacokinetic variability may be unpredictable, the antimicrobial policy may further benefit from real-time application of therapeutic drug monitoring, since this practice, by tailoring exposure to the individual patient, may consequently be helpful both in improving the outcome of antimicrobial therapy and in containing the spread of resistance in the hospital setting.

Effect of cirrhosis on antibiotic efficacy in a rat model of pneumococcal pneumonia

A rat model was used to study the effects of cirrhosis on antibiotic therapy of pneumococcal pneumonia. Cirrhotic and control male Sprague-Dawley rats were infected transtracheally with type 3 Streptococcus pneumoniae. Treatment began 18 h later with phosphate-buffered saline (PBS), azithromycin (50 mg/kg), trovafloxacin (50 mg/kg), or ceftriaxone (100 mg/kg) injected subcutaneously twice daily for 5 days. Antibiotic concentrations were measured by high-performance liquid chromatography. Azithromycin, trovafloxacin, and ceftriaxone were all equally effective at preventing mortality in both cirrhotic and normal rats. Free fraction area under the curve to minimum inhibitory concentration ratio (AUC/MIC) and maximum calculated serum concentration to MIC ratio (C(max)/MIC) and percent time that the serum concentration exceeded the MIC (%T > MIC) were greater for ceftriaxone compared with azithromycin or trovafloxacin. Azithromycin achieved higher concentrations in bronchoalveolar lavage fluid (BALF), epithelial lining fluid (ELF), and BAL white blood cells than ceftriaxone or trovafloxacin in cirrhotic rats. Macrolide, beta-lactam, or fluoroquinolone antibiotic efficacy in a pneumococcal pneumonia model does not appear to be affected by hepatic cirrhosis.

Ceftriaxone: an update of its use in the management of community-acquired and nosocomial infections

Ceftriaxone is a parenteral third-generation cephalosporin with a long elimination half-life which permits once-daily administration. It has good activity against Streptococcus pneumoniae, methicillin-susceptible staphylococci, Haemophilus influenzae, Moraxella catarrhalis and Neisseria spp. Although active against Enterobacteriaceae, the recent spread of derepressed mutants which hyperproduce chromosomal beta-lactamases and extended-spectrum beta-lactamases has diminished the activity of all third-generation cephalosporins against these pathogens necessitating careful attention to sensitivity studies. Extensive data from randomised clinical trials confirm the efficacy of ceftriaxone in serious and difficult-to-treat community-acquired infections including meningitis, pneumonia and nonresponsive acute otitis media. Ceftriaxone also has efficacy in other community-acquired infections including uncomplicated gonorrhoea, acute pyelonephritis and various infections in children. In the nosocomial setting, extensive data also confirm the efficacy of ceftriaxone with or without an aminoglycoside in serious Gram-negative infections, pneumonia, spontaneous bacterial peritonitis and as surgical prophylaxis. Outpatient use of ceftriaxone, either as part of a step-down regimen or parenterally, is a distinguishing feature of the data gathered on the agent over the last decade. The review focuses on new applications of the drug and its use in infections in which the causative pathogens or their resistance patterns have changed over the past decade. Ceftriaxone has a good tolerability profile, the most common events being diarrhoea, nausea, vomiting, candidiasis and rash. Ceftriaxone may cause reversible biliary pseudolithiasis, notably at higher dosages of the drug (>/=2 g/day); however, the incidence of true lithiasis is <0.1%. Injection site discomfort or phlebitis can occur after intramuscular or intravenous administration.

CONCLUSIONS

As a result of its strong activity against S. pneumoniae, ceftriaxone holds an important place, either alone or as part of a combination regimen, in the treatment of invasive pneumococcal infections, including those with reduced beta-lactam susceptibility. Its once-daily administration schedule allows simplification of otherwise complex regimens in a hospital setting and has also contributed to its popularity as a parenteral agent in an ambulatory setting. These properties, together with a well characterised tolerability profile, mean that ceftriaxone is likely to retain its place as an important third-generation cephalosporin in the treatment of serious community-acquired and nosocomial infections.

Parenteral antibiotic prophylaxis of bacterial infections does not improve cost-efficacy of oral norfloxacin in cirrhotic patients with gastrointestinal bleeding

OBJECTIVE

Selective intestinal decontamination with norfloxacin is useful in the prevention of bacterial infections in cirrhotic patients with gastrointestinal bleeding. However, bleeding cirrhotic patients with ascites, encephalopathy, or shock are at high risk to develop bacterial infections in spite of prophylactic norfloxacin. The aim of this study was to assess whether the addition of intravenous ceftriaxone could improve the efficacy of prophylaxis with norfloxacin in these patients.

METHODS

Fifty-six cirrhotic patients with gastrointestinal hemorrhage and ascites, encephalopathy, or shock were randomized into two groups: Group 1 (n = 28) received oral norfloxacin 400 mg/12 h for 7 days, and group 2 (n = 28) received norfloxacin plus intravenous ceftriaxone 2 g daily during the first 3 days of admission.

RESULTS

Ten patients were excluded because of community-acquired infection, surgery, or death within the first 24 h. The incidence of bacterial infections during hospitalization was 18.1% in group 1 and 12.5% in group 2 (p = NS). The incidence of severe infections (spontaneous bacterial peritonitis, bacteremia, or pneumonia) was also similar in both groups: 9% in group 1 versus 8.3% in group 2 (p = NS). There were no statistical differences between the two groups with respect to duration of hospitalization or mortality. The cost of antibiotic therapy (including prophylaxis and treatment of infections) was significantly higher in group 2.

CONCLUSION

These results suggest that the addition of intravenous ceftriaxone during the first 3 days of hospitalization does not improve the cost-efficacy of oral norfloxacin in the prevention of bacterial infections in cirrhotic patients with gastrointestinal bleeding and high risk of infection.

Cefotaxime. A reappraisal of its antibacterial activity and pharmacokinetic properties, and a review of its therapeutic efficacy when administered twice daily for the treatment of mild to moderate infections

Cefotaxime is well established as an effective and well tolerated antibacterial drug for 3 times daily parenteral treatment of a variety of moderate to severe infections in hospitalised patients. Its frequency of administration has recently been reassessed with a 12-hourly regimen. Comparative studies in hospitalised patients with nosocomial or community-acquired lower respiratory tract infections, demonstrate the similar clinical and bacteriological efficacy of twice daily cefotaxime 1 or 2 g and the same daily dose of ceftriaxone, usually administered once daily. Cefotaxime 2 g twice daily was also similar in efficacy to ceftriaxone 2 g once daily. Retrospective and post-marketing studies also reveal the similar efficacy of cefotaxime administered twice and 3 times daily, and pharmacoeconomic studies suggest that total direct costs of treatment with cefotaxime compared is similar to that with other third generation cephalosporins in currently used dosage regimens. When administered twice daily, cefotaxime is, thus, an effective antibacterial agent for the treatment of hospitalised patients outside the intensive care unit with a variety of mild to moderate non-CNS infections caused by susceptible organisms. When appropriately administered twice daily there is potential to lower the cost of antibacterial treatment without compromising efficacy.

Experience with cefotaxime in the treatment of spontaneous bacterial peritonitis in cirrhosis

Spontaneous bacterial peritonitis (SBP) is a severe infectious complication in cirrhotic patients, and initial antibiotic therapy must be empirical. An initial study published in 1985 found that cefotaxime administered at a dose of 2 g every 4 h was more effective and safer than the combination of tobramycin-ampicillin. Since then, cefotaxime has been considered the agent of choice in the empiric therapy of SBP. Subsequent publications showed that a dosage of 2 g every 6 h was also adequate in this infection. More recent studies have demonstrated that the high efficacy of cefotaxime in SBP can be maintained by using lower dosages than those used in initial investigations. In one of these studies, a dose of 2 g every 8 h for 5 days was found to be as effective as the same dose for 10 days. Finally, a prospective, randomized multicenter trial aimed at comparing the efficacy of two different dosages of cefotaxime, 2 g every 6 h versus 2 g every 12 in a large series of cirrhotic patients with SBP, showed that both dosages resulted in similar rates of resolution of infection and survival. Despite the reasonably adequate rate of infection resolution in SBP patients, the in-hospital mortality rate remains high as a result of complications such as renal failure. Further studies should therefore be addressed to reducing the incidence of these complications and thus improving survival.

Two different dosages of cefotaxime in the treatment of spontaneous bacterial peritonitis in cirrhosis: results of a prospective, randomized, multicenter study

Cefotaxime (CTX) is considered one of the first-choice antibiotics in the therapy of spontaneous bacterial peritonitis (SBP) in cirrhosis. Because CTX is largely metabolized in the liver, this drug may also be effective in SBP by administering lower doses than those habitually used. To investigate this possibility, a prospective, randomized, multicenter study was performed to compare the therapeutic efficacy of two different dosages of CTX in 143 patients with SBP: 71 (group I) were allocated to receive a high dose (2 g every 6 hours, which is one of the most frequently recommended doses in this infection), and 72 (group II) were allocated to receive a low dose (2 g every 12 hours). At inclusion, both groups were similar in relation to clinical and laboratory data, with the exception of a higher incidence of positive ascitic fluid culture in group I than in group II (59% vs. 40%; P = .029). The rate of infection resolution was similar for both groups (77% vs. 79%). Hospital survival was also similar in both groups (69% vs. 79%). No difference was observed between patients with positive or negative ascitic fluid cultures with regard to infection resolution and patient survival. The duration of antibiotic therapy was similar in both groups (9.0 +/- 3.3 days in group I vs. 8.8 +/- 3.1 days in group II). In a subset of 13 patients from group I and 11 patients from group II CTX levels were determined in serum (peak and trough) and ascitic fluid (concomitantly with trough serum). Peak serum levels were similar in patients from both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Antimicrobial activity of 11 newer and investigational drugs tested against aerobic isolates from spontaneous bacterial peritonitis

The in vitro susceptibility of 124 aerobic bacterial pathogens isolated from patients with spontaneous bacterial peritonitis (SBP) were tested against 11 antimicrobial agents, including parenteral or oral cephalosporins and fluoroquinolones. Most SBP isolates were Gram-negative organisms, and Escherichia coli and Klebsiella pneumoniae were responsible for 63% of the episodes evaluated. The fluoroquinolones (ciprofloxacin and ofloxacin) and the "fourth-generation" cephalosporin cefpirome were the most active agents against the Gram-negative bacteria. Commonly used cefotaxime and cefotaxime-desacetylcefotaxime (DES-CTX) combinations were also very active against Gram-negative bacteria with only few Enterobacter cloacae isolates being resistant (minimum inhibitory concentrations > 32 micrograms/ml). All streptococci were susceptible to cefotaxime, cefpirome, and cefdaloxime and to the cefotaxime-DES-CTX combinations, whereas only ofloxacin demonstrated acceptable activity against the enterococci. The widest spectrum of activity versus SBP isolates was found for ofloxacin (98% susceptibility) among the fluoroquinolones. For the beta-lactams, the widest spectrum of activity was demonstrated by cefpirome and the 2:1 cefotaxime-DES-CTX combination (93% susceptibility). These results indicate that the role of ofloxacin and newer parenteral or orally administered cephalosporins in the treatment of prophylaxis of SBP should be further evaluated.

Randomized trial comparing ceftriaxone with cefonicid for treatment of spontaneous bacterial peritonitis in cirrhotic patients

We compared cefonicid (2 g every 12 h) and ceftriaxone (2 g every 24 h) for their efficacy and safety in treating spontaneous bacterial peritonitis in cirrhotic patients in an open randomized clinical trial (30 patients in each group). Clinical, laboratory, and bacteriologic characteristics were similar in both groups. Ceftriaxone-susceptible strains were isolated on 44 occasions (94%), and cefonicid-susceptible strains were isolated on 43 occasions (91.5%). The antibiotic concentration in ascitic fluid/MIC ratio for ceftriaxone was > 100 throughout the dose interval (24 h), while it was lower for cefonicid (between 1 and 18). A total of 100% of patients treated with ceftriaxone, and 94% of those treated with cefonicid were cured of their infections (P was not significant). Hospitalization mortality was 37% in the cefonicid group and 30% in the ceftriaxone group (P was not significant). The time that elapsed between the initiation of treatment and the patient's death was shorter in the cefonicid group patients (5.3 +/- 3.90 days) than in the ceftriaxone group patients (11.8 +/- 9.15 days) (P < 0.05). None of the patients presented with superinfections, and only two patients treated with cefonicid and three patients treated with ceftriaxone developed colonizations with Enterococcus faecalis or Candida albicans. Ceftriaxone and cefonicid are safe and useful agents for treating cirrhotic spontaneous bacterial peritonitis, although the pharmacokinetic characteristics of ceftriaxone seem to be more advantageous than those of cefonicid.

Infections in the surgical setting: epidemiology and effect of treatment with cefotaxime in a multicenter trial including 3,032 patients

Hospital-acquired infections still represent a serious threat to the surgical patient. A nationwide survey of 259 Italian surgical wards involving 11,343 patients was conducted in October 1988. Hospital-acquired infections were recorded in 565 (5%) patients: the microorganisms most commonly involved were gram-negative rods (60% of all isolates), 41% of the infected patients presented one or more intrinsic predisposing factor, and 65% had undergone some invasive procedure. The studied group represented 23% of all surgical patients in the country on the days of the survey. Following the epidemiologic survey, an open multicenter study was conducted in the same wards to evaluate the efficacy and tolerability of cefotaxime (1 g, 2 or 3 times per day) in the treatment of nosocomial surgical infections. Among 3,032 evaluable patients, 1,295 intra-abdominal, 610 wound and soft tissue, 554 urinary, and 367 respiratory infections were observed. Treatment was judged to be clinically effective in 94% of patients, and side effects, mostly involving the gastrointestinal tract, were observed in 1.4% of patients; but interruption of the treatment was required only in 19 patients (0.6%). This study confirms that cefotaxime, after over a decade of use, retains high efficacy in the treatment for nosocomial infections and induces a low rate of side effects.

Pharmacokinetics of cefotaxime and desacetylcefotaxime in patients with liver disease

The dispositions of cefotaxime and its metabolite desacetylcefotaxime were investigated in patients with different forms of chronic parenchymal liver disease (CPLD). A total of 31 subjects (27 patients and 4 controls) received a single 2-g dose of cefotaxime by infusion, and serial blood samples were drawn. The area under the concentration-time curve ranged from 176 to 241 micrograms.h/ml, the apparent half-life ranged from 1.49 to 2.42 h, and clearance ranged from 2.06 to 3.10 ml/min/kg in patients with four different forms of CPLD. The area under the concentration-time curve and the apparent half-life of desacetylcefotaxime ranged from 72 to 128 micrograms.h/ml and 7.1 to 13.4 h, respectively. Pharmacokinetic parameters were significantly different in patients with CPLD compared with those in control subjects and were related to clinical indices of hepatic impairment. Modest accumulation of cefotaxime in patients with severe hepatic impairment is unlikely to produce toxicity because of its high therapeutic index, and dosing modifications may not be required.

Clearance of ceftriaxone in critical care patients with acute renal failure

Serum concentrations of ceftriaxone (RocephinTM), a third generation cephalosporin, were monitored in 5 operative intensive care patients suffering from acute renal failure (ARF) and compared to those of 7 patients without renal disturbance. For a period of 7 days, a fixed dose of 2 g/day was given by a 15 min infusion. Pharmacokinetic parameters were calculated by fitting all serum and urine data measured over the period of treatment. Ceftriaxone free fraction was measured on days 2 and 7. There was no evidence for an intraindividual change in ceftriaxone-clearance during the observation period. Ceftriaxone renal clearance was closely dependent on creatinine clearance according to a linear regression expressed by Clren = 0.14 Clcrea + 2.2 (r = 0.951, p less than 0.0001). Total clearance was also associated with creatinine clearance: Cltot = 0.19 Clcrea + 8.2 (r = 0.964, p less than 0.0001). Related to the free fraction, renal clearance was in the range of the glomerular filtration rate. Non-renal clearance was strongly decreased when related to the free fraction indicating that biliary excretion is also impaired in patients with acute renal failure. Obviously no compensatory increase in hepatic ceftriaxone clearance takes place. It is concluded that elimination of ceftriaxone may be strongly impaired during acute renal failure in surgical intensive care patients and that dosage should be restricted according to degree of the impairment of creatinine clearance.

Pharmacokinetics of intravenous cefetamet and oral cefetamet pivoxil in patients with hepatic cirrhosis

The pharmacokinetics of orally administered cefetamet pivoxil and intravenously administered cefetamet were studied in 12 healthy subjects and 12 patients with hepatic cirrhosis without ascites. Cirrhosis had no detectable effect on the pharmacokinetics of cefetamet and on the bioavailability of cefetamet pivoxil. After intravenous cefetamet in control versus cirrhotic subjects, respectively, the following mean +/- standard deviation values were observed: total body clearance, 128 +/- 10.2 versus 123 +/- 28.8 ml/min; steady-state volume of distribution, 23.2 +/- 2.2 versus 22.7 +/- 4.6 liters; half-life, 2.42 +/- 0.21 versus 2.35 +/- 0.41 h. Renal and nonrenal clearances of cefetamet were similar in both groups, as were the mean residence times and areas under the plasma concentration-time curve. For oral cefetamet pivoxil, no differences were detected in the mean values of the percentage of dose absorbed: 44.6 +/- 9.1 versus 50.1 +/- 12.9. The rate of appearance of cefetamet in the plasma also was not affected by cirrhosis: similar mean values were found for the mean residence time and the maximum concentration in plasma and its time of occurrence.