Comparison of cefoperazone with penicillin, ampicillin, gentamicin, and chloramphenicol in the therapy of experimental meningitis

Antibiotic Distribution into Cerebrospinal Fluid: Can Dosing Safely Account for Drug and Disease Factors in the Treatment of Ventriculostomy-Associated Infections?

Ventriculostomy-associated infections, or ventriculitis, in critically ill patients are associated with considerable morbidity. Efficacious antibiotic dosing for the treatment of these infections may be complicated by altered antibiotic concentrations in the cerebrospinal fluid due to variable meningeal inflammation and antibiotic properties. Therefore, doses used to treat infections with a higher degree of meningeal inflammation (such as meningitis) may often fail to achieve equivalent exposures in patients with ventriculostomy-associated infections such as ventriculitis. This paper aims to review the disease burden, infection rates, and common pathogens associated with ventriculostomy-associated infections. This review also seeks to describe the disease- and drug-related factors that influence antibiotic distribution into cerebrospinal fluid and provide a critical appraisal of current dosing of antibiotics commonly used to treat these types of infections. A Medline search of relevant articles was conducted and used to support a review of cerebrospinal fluid penetration of vancomycin, including critical appraisal of the recent paper by Beach et al. recently published in this journal. We found that in the intensive care unit, ventriculostomy-associated infections are the most common and serious complication of external ventricular drain insertion and often result in prolonged patient stay and increased healthcare costs. Reported infection rates are extremely variable (between 0 and 45%), hindered by the inherent diagnostic difficulty. Both Gram-positive and Gram-negative organisms are associated with such infections and the rise of multi-drug-resistant pathogens means that effective treatment is an ongoing challenge. Disease factors that may need to be considered are reduced meningeal inflammation and the presence of critical illness; drug factors include physiochemical properties, degree of plasma-protein binding, and affinity to active transporter proteins present in the blood-cerebrospinal fluid barrier. The relationship between cerebrospinal fluid antibiotic exposures in the setting of ventriculostomy-associated infection and clinical response has not been fully elucidated for many of the antibiotics commonly used in its treatment. More thorough and clinically relevant investigations are needed to better define blood pharmacokinetic/pharmacodynamics targets and optimal therapeutic exposures for treatment of ventriculostomy-associated infections. It is hoped that this future research will be able to provide clearer recommendations for clinicians frequently faced with dosing-related dilemmas when treating patients with these challenging infections.

Drug concentrations in the serum and cerebrospinal fluid of patients treated with cefoperazone/sulbactam after craniotomy

BACKGROUND

To identify changes in cefoperazone/sulbactam penetration into cerebrospinal fluid (CSF) after craniotomy and to investigate preliminarily whether cefoperazone/sulbactam CSF concentration can reach therapeutic level when administered intravenously after neurosurgical operation.

METHODS

Neurosurgical patients with an indwelling ventricular drainage pipe who received prophylactic cefoperazone/sulbactam for the treatment of intracranial infection were received a cefoperazone/sulbactam 2:1, 3.0-g infusion for 3 hours every 6 hours for 24 h. Venous blood and CSF specimens were collected to determine cefoperazone/sulbactam concentrations.

RESULTS

The cefoperazone and sulbactam concentrations in serum were highest at the second hour (237.54 ± 336.72 mg/L and 66.52 ± 80.38 mg/L, respectively) and then decreased. The cefoperazone and sulbactam concentrations in CSF were highest at the 4th hour (39.22 ± 75.55 mg/L and 6.24 ± 8.35 mg/L, respectively) and then decreased. CSF penetration measured by the ratio of peak concentrations (CSF/serum) was 8.6% ± 7.2% for cefoperazone and 13.5% ± 11.9% for sulbactam, CSF penetration measured by the ratio of trough concentrations (CSF/serum) was 13.4% ± 5.3% for cefoperazone and 106.5% ± 87.5% for sulbactam. CSF penetration represented by the ratio of area under the curve (AUC) of CSF and serum was 14.5% for cefoperazone and 22.6% for sulbactam. Neurosurgical impairment of the blood-brain barrier may improve the CSF penetration of these drugs, but it is difficult to reach the MIC90 of resistant bacteria. If single intravenous administration time was extended to 3 hours, the serum concentrations of drugs were able to meet the PK/PD standard (T> MIC%> 50%) for treating common, highly resistant bacteria.

CONCLUSIONS

The CSF penetration of cefoperazone/sulbactam may be enhanced after neurosurgical impairment of the blood-brain barrier. This study is a pilot research of cefoperazone/sulbactam using in neurosurgical individuals, However, it needs to be confirmed by further large-scale studies.

Pharmacokinetics and pharmacodynamics of antibiotics in meningitis

The penetration of antimicrobials into the CSF is dependent on lipid solubility, molecular size, capillary and choroid plexus efflux pumps, protein binding, and the degree of inflammation. Penicillins, certain cephalosporins, carbapenems, fluoroquinolones, vancomycin, and rifampin provide the highest ratios of CSF levels to the MBC for common infecting organisms. For beta-lactam antibiotics, it is the duration of time that CSF concentrations exceed the MBC that determines the rate of bactericidal activity. It appears that levels should exceed the MBC for more than 50% of the dosing interval. The peak/MBC and AUC/MBC ratios are important determinants of efficacy for aminoglycosides and fluoroquinolones. Once-daily dosing of aminoglycosides is as effective as multiple-daily dosing regimens in experimental meningitis, probably because of drug-induced prolonged persistent effects. Fluoroquinolones do not produce as prolonged persistent effects and are slightly less effective when administered once daily. Although steroid use can reduce the penetration and decrease the bactericidal activity of some antimicrobials, such as vancomycin, in experimental meningitis, the clinical impact of steroid use in human meningitis is still unclear.

Use of ampicillin-sulbactam for treatment of experimental meningitis caused by a beta-lactamase-producing strain of Escherichia coli K-1

We evaluated the pharmacokinetics and therapeutic efficacy of ampicillin combined with sulbactam in a rabbit model of meningitis due to a beta-lactamase-producing strain of Escherichia coli K-1. Ceftriaxone was used as a comparison drug. The MIC and MBC were 32 and greater than 64 micrograms/ml (ampicillin), greater than 256 and greater than 256 micrograms/ml (sulbactam), 2.0 and 4.0 micrograms/ml (ampicillin-sulbactam [2:1 ratio, ampicillin concentration]) and 0.125 and 0.25 micrograms/ml (ceftriaxone). All antibiotics were given by intravenous bolus injection in a number of dosing regimens. Ampicillin and sulbactam achieved high concentrations in cerebrospinal fluid (CSF) with higher dose regimens, but only moderate bactericidal activity compared with that of ceftriaxone was obtained. CSF bacterial titers were reduced by 0.6 +/- 0.3 log10 CFU/ml/h with the highest ampicillin-sulbactam dose used (500 and 500 mg/kg of body weight, two doses). This was similar to the bactericidal activity achieved by low-dose ceftriaxone (10 mg/kg), while a higher ceftriaxone dose (100 mg/kg) produced a significant increase in bactericidal activity (1.1 +/- 0.4 log10 CFU/ml/h). It appears that ampicillin-sulbactam, despite favorable CSF pharmacokinetics in animals with meningitis, may be of limited value in the treatment of difficult-to-treat beta-lactamase-producing bacteria, against which the combination shows only moderate in vitro activity.

Evaluation of piperacillin-tazobactam in experimental meningitis caused by a beta-lactamase-producing strain of K1-positive Escherichia coli

We evaluated the pharmacokinetics and therapeutic efficacy of piperacillin combined with tazobactam, a novel beta-lactamase inhibitor, in experimental meningitis due to a beta-lactamase-producing strain of K1-positive Escherichia coli. Different doses of piperacillin and tazobactam, as single agents and combined (8:1 ratio; dosage range, 40/5 to 200/25 mg/kg per h), and of ceftriaxone were given to experimentally infected rabbits by intravenous bolus injection followed by a 5-h constant infusion. The mean (+/- standard deviation) rates for penetration into the cerebrospinal fluid of infected animals after coadministration of both drugs were 16.6 +/- 8.4% for piperacillin and 32.5 +/- 12.6% for tazobactam. Compared with either agent alone, combination treatment resulted in significantly better bactericidal activity in the cerebrospinal fluid. The bactericidal activity of piperacillin-tazobactam was dose dependent: cerebrospinal fluid bacterial titers were reduced by 0.37 +/- 0.19 log10 CFU/ml per h with the lowest dose versus 0.96 +/- 0.25 log10 CFU/ml per h with the highest dose (P less than 0.001). At the relatively high doses of 160/20 and 200/25 mg of piperacillin-tazobactam per kg per h, the bactericidal activity of the combination was comparable to that of 10 and 25 mg of ceftriaxone per kg per h, respectively.

Cefoperazone therapy of bacterial meningitis: a clinical trial

Sixteen hospitalized patients, aged between 10 and 76 years (mean: 34.3 years), with bacterial meningitis were treated i.v. with cefoperazone at daily doses of 4.5 g to 9 g. In two cases ampicillin was given in combination with cefoperazone during the last four days and the first five days of treatment, respectively. The following organisms were isolated: Neisseria meningitidis (n = 9), Haemophilus influenzae (n = 3), Escherichia coli (n = 2), Streptococcus pneumoniae (n = 2). Fourteen patients completely recovered from infection and the pathogens were eradicated; the treatment failed in only two patients and both were cured with alternative treatment. Furthermore, in 11 patients cefoperazone serum and CSF levels were determined four times during the first week of treatment (1st, 3rd, 5th and 7th days). No important side effects were recorded.

Cephalosporins in the treatment of meningitis

The synthesis of new cephalosporin antibiotics has provided agents which can effectively be used to treat most of the different forms of meningitis. None of the first generation cephalosporins can be considered acceptable as agents to treat meningitis. Cefuroxime can be used to treat meningitis due to Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis in children. Agents such as cefotaxime and ceftriaxone are appropriate for neonatal meningitis due to Escherichia coli and group B streptococci, but not Listeria monocytogenes. Cefotaxime, ceftriaxone, ceftizoxime and ceftazidime have all proved effective as therapy of meningitis in children and adults when the pathogens are pneumococci, H. influenzae or N. meningitidis, but they have not been shown to yield an improved mortality or lower morbidity in spite of much greater cerebrospinal fluid (CSF) bactericidal titres. Cefotaxime, ceftizoxime, ceftriaxone and ceftazidime have been effective as therapy of meningitis due to E. coli, K. pneumoniae and Proteus species, but failures have occurred with all of the cephalosporins when used to treat meningitis due to Enterobacter spp. and Serratia marcescens. Only ceftazidime yields adequate CSF concentrations to treat meningitis due to Pseudomonas aeruginosa. Overall, the cephalosporins can now be considered a major component of the therapy of acute bacterial meningitis irrespective of the age group to be treated.

Penetration of amoxicillin and potassium clavulanate into the cerebrospinal fluid of patients with inflamed meninges

A single intravenous dose of 2.0 g of amoxicillin and 0.2 g of potassium clavulanate was given to patients with bacterial meningitis, and the pharmacokinetics of both drugs in the cerebrospinal fluid (CSF) and plasma were evaluated. Twenty-one patients aged 14 to 76 years were studied. Both amoxicillin and potassium clavulanate were detectable in the CSF as early as 1 h and reached peak concentrations by approximately 2 h. The highest mean CSF concentrations were 2.25 micrograms/ml for amoxicillin and 0.25 micrograms/ml for potassium clavulanate and were found in patients with moderately or severely inflamed meninges. The CSF penetration relative to plasma for amoxicillin and potassium clavulanate was 5.8 and 8.4%, respectively. These levels suggest that the amoxicillin-potassium clavulanate combination may be effective for the treatment of bacterial meningitis caused by beta-lactamase-producing pathogens.

New cephalosporins cefotaxime, cefpimizole, BMY 28142, and HR 810 in experimental pneumococcal meningitis in rabbits

Four new cephalosporins, cefotaxime, cefpimizole (U 63196E), BMY 28142, and HR 810 were evaluated in experimental pneumococcal meningitis. Cefotaxime penetrated only moderately into the cerebrospinal fluid of rabbits with meningitis, whereas cefpimizole, BMY 28142, and HR 810 all exhibited unusually good penetration. The bactericidal activity in infected cerebrospinal fluid was comparable for the four drugs.

Clinical pharmacokinetics of the third generation cephalosporins

At the present time, the third generation cephalosporins that are already on the market or close to this point include cefsulodin, cefotaxime, cefoperazone, latamoxef, ceftriaxone, ceftazidime, ceftizoxime and cefotetan. Other newer compounds are also under development but have not been included in this review. None of the third generation compounds is suitable for oral administration and, accordingly, their pharmacokinetics have been studied only after intravenous and intramuscular administration. Microbiological assays and HPLC methods have been used for the measurement of plasma/serum, urine, bile and cerebrospinal fluid (CSF) concentrations. As found with cefotaxime, microbiological assays should only be used when the full metabolite spectrum of a particular drug is known, as otherwise, the presence of microbiologically active metabolites may lead to erroneous conclusions. Under normal conditions, the major route of elimination is via the kidneys for cefsulodin, latamoxef, ceftazidime, ceftizoxime and cefotetan. In contrast, cefoperazone is mainly eliminated in the bile, whereas cefotaxime and ceftriaxone depend both on the liver and the kidneys for their elimination. With the exception of ceftriaxone, which has a longer elimination half-life (i.e. around 8 hours), all the other third generation cephalosporins have a t1/2 ranging between 1.5 and 2.5 hours. Plasma protein binding is variable from one compound to another. However, the clinical relevance of this parameter is not clearly established since tissue penetration also depends on the relative affinity of the drug for tissue components. Third generation cephalosporins seem to penetrate adequately into the CSF and, thus pharmacokinetically appear to be appropriate agents for the treatment of meningitis. The degree of modification of pharmacokinetic parameters by renal insufficiency or hepatic diseases depends, as for other drugs, on the extent to which the compound is excreted via the kidneys or the liver. The third generation cephalosporins have been extensively studied under these conditions and recommendations for dosage modification in special circumstances are available for most of them. The pharmacokinetics of some third generation cephalosporins may be modified in neonates and elderly patients. Accordingly, their use at the extremes of age must be accompanied by a closer than usual clinical monitoring of the patient. From a clinical point of view, the third generation cephalosporins possess reliable pharmacokinetic properties.(ABSTRACT TRUNCATED AT 400 WORDS)

Antimicrobial therapy of experimental meningitis caused by Streptococcus pneumoniae strains with different susceptibilities to penicillin

The pharmacokinetics and bacteriological efficacies of penicillin G, ceftriaxone, vancomycin, and imipenem were determined in rabbits with experimental meningitis caused by Streptococcus pneumoniae strains with different penicillin susceptibilities. Drug dosages were adjusted to attain peak concentrations in serum that were similar to those observed in infants and children. In animals infected with a penicillin-susceptible (MBC, 0.008 micrograms/ml) pneumococcus, penicillin G and ceftriaxone reduced the number of organisms in cerebrospinal fluid (CSF) by greater than or equal to 4.14 log10 CFU/ml after single doses and after 9-h continuous infusions. A single large dose (50 mg/kg) of penicillin G was comparatively ineffective (-2.15 log10 CFU/ml) against a relatively penicillin-resistant (MBC, 0.5 micrograms/ml) strain, whereas ceftriaxone therapy resulted in a 3.66- and 4.77-log10 CFU/ml reduction after single doses and 9-h continuous infusions, respectively. In animals in which meningitis was caused by a penicillin-resistant (MBC, 8.0 micrograms/ml) pneumococcus, a single dose of penicillin (50 or 150 mg/kg) or of ceftriaxone failed to lower the number of organisms in CSF. Vancomycin and imipenem reduced the counts in CSF by at least 2.19 and 4.10 log10 CFU/ml after single doses and 9-h infusions, respectively. In all experiments, a bactericidal titer of greater than or equal to 1:8 in CSF was necessary to achieve a maximal bacteriological effect.

Rationale for optimal dosing of beta-lactam antibiotics in therapy for bacterial meningitis

This review considers the five major principles governing optimal dosing of beta-lactam antibiotics in therapy for bacterial meningitis: off the entry of passage of antibiotics into CSF, (2) the antimicrobial activity of beta-lactams within the purulent CSF in vivo, (3) the bactericidal activity within the CSF, (4) the route and mode of drug administration together with the postantibiotic effect, and (5) the duration of therapy. Special attention is paid to the third principle, bactericidal activity within the CSF, employing the model of the newer, third-generation cephalosporins used in the treatment of meningitis caused by gram-negative aerobic bacilli.

Cefoperazone pharmacokinetics in acute childhood meningitis

We studied the serum pharmacokinetics and cerebrospinal fluid concentrations of cefoperazone in 15 children with acute meningitis. Mean cefoperazone concentrations of 117 micrograms/ml in the serum and 3.8 micrograms/ml in the cerebrospinal fluid were noted 2 hours after a single 100 mg/kg dose. Following multiple 50 or 100 mg/kg doses, the mean peak serum cefoperazone concentrations were 232 and 498 micrograms/ml, respectively, with an overall mean elimination phase half-life of 2.12 hours. The data best fit a linear, two-compartment model. Cerebrospinal fluid concentrations 1.5 to 2.5 hours after the end of cefoperazone infusions ranged from 1.4 to 19.2 micrograms/ml for all doses and states of illness. This represented 1.2% to 6.4% of simultaneous serum values. The cerebrospinal fluid inhibitory titer was greater than or equal to 1:16 in 17 of 18 specimens tested against a strain of Haemophilus influenzae type b resistant to both chloramphenicol and ampicillin. In the doses given, cefoperazone produces adequate cerebrospinal fluid concentrations and bioactivity to treat the common bacterial forms of acute meningitis in infants and children.

Concentrations of cefoperazone in cerebrospinal fluid during bacterial meningitis

Cefoperazone was administered to 15 patients with bacterial meningitis before lumbar punctures were performed. Patients received one of the following three dosage regimens before collection of cerebrospinal fluid (CSF): one dose of 50 mg/kg (maximum, 2 g; group I), one dose of 100 mg/kg (maximum, 4 g; group II), three doses of 100 mg/kg each every 8 h (maximum, 4 g each dose; group III). Of 44 CSF samples, 26 had detectable cefoperazone levels (59%); drug concentrations in CSF ranged from less than 0.8 to 11.5 micrograms/ml (median, 1.97 micrograms/ml). Although the percentage of patients with detectable cefoperazone levels in CSF was higher in group III (69%) than in group II (64%) or group I (50%), the differences were not statistically significant; however, the mean drug concentration in CSF in group I (1.53 micrograms/ml) was significantly lower than that in group III (3.1 micrograms/ml). A high protein concentration in CSF (as an indicator of meningeal inflammation) correlated best with high cefoperazone concentrations in CSF. These findings differ from previous investigations of cefoperazone penetration into CSF; however, cefoperazone may not penetrate reliably into CSF and therefore may not be an optimal candidate drug for the treatment of bacterial meningitis.

Bactericidal versus bacteriostatic antibiotic therapy of experimental pneumococcal meningitis in rabbits

A rabbit model of pneumococcal meningitis was used to examine the importance of bactericidal vs. bacteriostatic antimicrobial agents in the therapy of meningitis 112 animals were infected with one of two strains of type III Streptococcus pneumoniae. Both strains were exquisitely sensitive to ampicillin, minimum inhibitory concentration (MIC)/minimum bactericidal concentration (MBC)<0.125 mug/ml. The activity of chloramphenicol against the two strains varied: strain(1)-MIC 2 mug/ml, MBC 16 mug/ml; strain(2)-MIC 1 mug/ml, MBC 2 mug/ml. Animals were treated with either ampicillin or chloramphenicol in dosages that achieved a peak bactericidal effect in cerebrospinal fluid (CSF) for ampicillin against both strains. Two different dosages were used for chloramphenicol. The first dosage achieved a peak CSF concentration of 4.4+/-1.1 mug/ml that produced a bacteriostatic effect against strain(1) and bactericidal effect against strain(2). The second dosage achieved a bactericidal effect against both strains (mean peak CSF concentration 30.0 mug/ml). All animals were treated intramuscularly three times a day for 5 d. CSF was sampled daily and 3 d after discontinuation of therapy for quantitative bacterial cultures. Results demonstrate that only antimicrobial therapy that achieved a bactericidal effect in CSF was associated with cure. Over 90% of animals treated with one of the bactericidal regimens (i.e., animals in which the bacterial counts in CSF dropped >5 log(10) colony-forming units [cfu]/ ml after 48 h) had sterile CSF after 5 d of treatment. On the other hand, the regimen that achieved bacteriostatic concentrations (CSF drug concentrations between the MIC and MBC) produced a drop of 2.4 log(10) cfu/ml by 48 h; however, none of the animals that survived had sterile CSF after 5 d. These studies clearly demonstrate in a strictly controlled manner that maximally effective antimicrobial therapy of experimental pneumococcal meningitis depends on achieving a bactericidal effect in CSF.