Pharmacokinetics Of Cefoperazone Research Articles

Developmental population pharmacokinetics-pharmacodynamics and dosing optimization of cefoperazone in children.

To evaluate the population pharmacokinetics of cefoperazone in children and establish an evidence-based dosing regimen using a developmental pharmacokinetic-pharmacodynamic approach in order to optimize cefoperazone treatment. A model-based, open-label, opportunistic-sampling pharmacokinetic study was conducted in China. Blood samples from 99 cefoperazone-treated children were collected and quantified by HPLC/MS. NONMEM software was used for population pharmacokinetic-pharmacodynamic analysis. This study was registered at ClinicalTrials.gov (NCT03113344). A two-compartment model with first-order elimination agreed well with the experimental data. Covariate analysis showed that current body weight had a significant effect on the pharmacokinetics of cefoperazone. Monte Carlo simulation showed that for bacteria for which cefoperazone has an MIC of 0.5 mg/L, 78.1% of hypothetical children treated with '40 mg/kg/day, q8h, IV drip 3 h' would reach the pharmacodynamic target. For bacteria for which cefoperazone has an MIC of 8 mg/L, 88.4% of hypothetical children treated with 80 mg/kg/day (continuous infusion) would reach the treatment goal. A 160 mg/kg/day (continuous infusion) regimen can cover bacteria for which cefoperazone has an MIC of 16 mg/L. Nevertheless, even if using the maximum reported dose of 160 mg/kg/day (continuous infusion), the ratio of hypothetical children reaching the treatment target was only 9.9% for bacteria for which cefoperazone has an MIC of 32 mg/L. For cefoperazone, population pharmacokinetics were evaluated in children and an appropriate dosing regimen was developed based on developmental pharmacokinetics-pharmacodynamics. The dose indicated in the instructions (20-160 mg/kg/day) can basically cover the clinically common bacteria for which cefoperazone has an MIC of ≤16 mg/L. However, for bacteria for which the MIC is >16 mg/L, cefoperazone is not a preferred choice.

PP-49 Population pharmacokinetics and dosing optimisation of cefoperazone in children

Background Cefoperazone is used in children with sus-pected or documented Gram-negative serious infections. Currently, its use is off-label partly because of lack of phar-macokinetic studies. Our aim was to evaluate the pop-ulation pharmacokinetics of Cefoperazone in children between 2–12 years of age and define the appropriate dose in order to optimise cefoperazone treatment in this vulnerable population. Methods Blood samples were collected from children treated with Cefoperazone and concentrations were quantified by HPLC-MS. Population pharmacokinetic analysis was performed using NONMEM software. Results The data from 83 children (age range: 2.2–10.8 years) were available for population pharmacokinet-ic analysis. A two-compartment model with first-order elimination showed the best fit with the data. A covariate analysis identified that current weight had a significant impact on cefoperazone pharmacokinetics. Conclusion The population pharmacokinetics of Cefop-erazone was evaluated in children between 2–12 years old and an evidence-based optimal dosing regimen was established based on simulation.

Comparative pharmacokinetics of cefoperazone following intravenous and intramuscular administration in goats

The pharmacokinetic profile of cefoperazone was studied in goats following intravenous and intramuscular administration of 20mg/kg body weight. Cefoperazone concentrations in serum were determined by microbiological assay technique using Escherichia coli (ATCC 10536) as test organism. Following i.v. administration, the cefoperazone serum concentration–time curve was best fitted in a two compartment open model. Cefoperazone has moderate distribution in the body of goats with Vdss of 0.44±0.03L/kg. The elimination half-life (T0.5(β)), area under curve (AUC) and total body clearance (Cltot) were 1.97±0.14h, 149.63±8.61μgml−1h−1, and 2.17ml/min/kg, respectively. Following i.m. administration, the drug was very rapidly absorbed, with an absorption half-life (T0.5(ab)) of 0.12±0.01h. The maximum serum concentration (Cmax) of 30.42±3.53μgml−1 was attained at (Tmax) 0.58±0.02h, with an elimination half-life (T0.5(el)) of 2.53±0.11h. The systemic bioavailability of cefoperazone in the goats after i.m. administration was 83.62% and in vitro protein binding was 20.34%. The serum concentrations of cefoperazone along 12h post i.m. injection in this study were exceeding the MIC of different susceptible micro-organisms responsible for serious disease problems. Consequently, a suitable intramuscular dosage regimen for cefoperazone was 20mg/kg repeated at 12h intervals in goats. The drug was detected in urine up to 12 and 18h following i.v. and i.m. administration, respectively.

Quantitative determination of unbound cefoperazone in rat bile using microdialysis and liquid chromatography

Cefoperazone is a third generation cephalosporin antibiotic with a broad spectrum against gram-positive and gram-negative bacteria. It is clinically effective in the treatment of the biliary tract infections. In the present study, we utilized microdialysis sampling technique with shunt linear probe for continuous monitoring levels of cefoperazone from rat biliary ducts. The effects of berberine (a potential P-glycoprotein enhancer) pretreatment were also evaluated. Analysis of cefoperazone in the dialysates was achieved using a reversed phase RP-18 column (250mm×4.6mm i.d.; particle size 5μm) maintained at ambient temperature. The mobile phase comprised 100mM monosodium phosphate (pH 5.5)–methanol (70:30, v/v), and the flow rate of the mobile phase was 1ml/min. The UV detector wavelength was set at 254nm. The area under the concentration–time curve and elimination half-life of cefoperazone were about 242.3±13.4minmg/ml and 64.1±28.2min, respectively. No significant effect was showed on the pharmacokinetics of cefoperazone with berberine pretreatment. This study represents a successful application of biliary microdialysis sampling technique, which is feasible for pharmacokinetic and biliary drug excretion studies.

Pharmacodynamics and pharmacokinetics of cefoperazone and cefamandole in dogs following single dose intravenous and intramuscular administration

The pharmacokinetics and intramuscular (i.m.) bioavailability of cefoperazone and cefamandole (20 mg/kg) were investigated in dogs and the findings related to minimal inhibitory concentrations (MICs) for 90 bacterial strains isolated clinically from dogs. The MICs of cefamandole for Staphylococcus intermedius (MIC 90 0.125 μg/mL) were lower than those of cefoperazone (MIC 90 0.5 μg/mL) although the latter was more effective against Escherichia coli strains (MIC 90 2.0 μg/mL vs. 4.0 μg/mL). The pharmacokinetics of the drugs after intravenous administrations were similar: a rapid distribution phase was followed by a slower elimination phase ( t (1/2) λ2 84.0±21.3 min for cefoperazone and 81.4±9.7 min for cefamandole). The apparent volume of distribution and body clearance were 0.233 L/kg and 1.96 mL/kg/min for cefoperazone, 0.190 L/kg and 1.76 mL/kg/min for cefamandole. After i.m. administration the bioavailability and peak serum concentration of cefamandole (85.1±13.5% and 35.9±5.4 μg/ mL ) were significantly higher than cefoperazone (41.4±7.1% and 24.5±3.0 μg/ mL ), but not the serum half-lives ( t 1/2el 134.3±12.6 min for cefoperazone and 145.4±12.3 min for cefamandole). The time above MIC 90 indicated that cefamandole can be administered once daily to dogs for the treatment of staphylococcal infections ( T>MIC for S. intermedius 23.8±0.3 and for Staphylococcus aureus 21.6±0.6 h).

Pharmacokinetics of Cefoperazone and Sulbactam in Liver Transplant Patients

The authors evaluated the pharmacokinetics of cefoperazone and sulbactam in 9 liver transplant patients. Cefoperazone and sulbactam were administered as an intravenous infusion over 30 minutes every 12 hours for six doses, and multiple blood samples were collected immediately after the first dose (administered during the surgery) and after the last dose. The concentrations of cefoperazone and sulbactam in serum and, when possible, in urine and bile collected over one dosing interval were measured by high-pressure liquid chromatography. The concentration of cefaperazone ranged from 436 to 4118 microg/ml, and sulbactam ranged from 3.3 to 8.7 microg/ml in the bile samples. The intraoperative clearance of cefoperazone (0.53+/-0.18 ml/min/kg) was significantly higher than the postoperative clearance (0.21+/-0.23 ml/min/kg). The half-life of cefaperazone, although not statistically significantly different, was prolonged in all patients during the postoperative period. The clearance of sulbactam (1.51+/-0.51 ml/min/kg) was lower than what is reported in patients with normal renal function but was comparable to what has been reported in patients with renal impairment and in critically ill patients. There were no significant differences in any of the pharmacokinetic parameters of sulbactam during and after surgery. The pharmacokinetic parameters of cefoperazone and sulbactam were significantly altered in liver transplant patients compared to what has been reported in normal subjects but were similar to what has been reported in patients with liver and renal impairment. There was a significant impairment in the biliary excretion of cefoperazone during the postoperative period in liver transplant patients. Although the percentage of the dose of cefoperazone excreted in the bile was drastically reduced, the biliary concentrations were generally high and above the MIC for most organisms. Given that both renal and hepatic elimination of cefoperazone is decreased, leading to a lower clearance and longer half-life in liver transplant patients, lower doses (1-2 g per day) of cefoperazone may be sufficient in liver transplant patients during the immediate postoperative period.

Pharmacokinetics of cefoperazone in horses.

The pharmacokinetics and bioavailability of cefoperazone (CPZ) were studied following intravenous (IV) and intramuscular (IM) administration of single doses (30 mg/kg) to horses. Concentrations in serum, urine and synovial fluid samples were measured following IV administration. CPZ concentrations in serum, synovial fluid and spongy bone samples were measured following IM administration. After IV administration a rapid distribution phase (t1/2 (alpha): 4.22 +/- 2.73 min) was followed by a slower elimination phase (t1/2(beta) 0.77 +/- 0.19 h). The apparent volume of distribution was 0.68 +/- 0.10 L/kg. Mean synovial fluid peak concentration was 5.76 +/- 0.74 microgram/mliter. After IM administration a bioavailability of 42.00 +/- 5.33% was obtained. Half-life of absorption was 2.51 +/- 0.72 min and t1/2(beta) was 1.52 +/- 0.15 h. The mean synovial fluid and spongy bone peak concentrations at 2 h after IM administration were 2.91 +/- 0.85 microgram/mliter and 5.56 +/- 0.70 microgram/mliter, respectively.

Effect of a bacterial lipopolysaccharide on biliary excretion of a beta-lactam antibiotic, cefoperazone, in rats.

Klebsiella pneumoniae O3 lipopolysaccharide (LPS) has been found to dramatically modify the pharmacokinetics of the beta-lactam antibiotic cefazolin in rats. This study investigated the effect of LPS on the biliary excretion of the beta-lactam antibiotic cefoperazone (CPZ) in rats. CPZ is known to be actively secreted into the bile by a carrier-mediated transport system. LPS (250 micrograms/kg of body weight) was infused for 20 to 30 min 2 h before an intravenous administration of CPZ (20 mg/kg). The pharmacokinetic parameters of CPZ were estimated by a noncompartment model. LPS induced a significant decrease in the systemic clearance (by approximately 50%) and an increase in the mean residence time of CPZ. Significant decreases were also seen in the bile flow rate and in the biliary recovery of unchanged CPZ in the LPS-treated rats. LPS tended to increase the proportion of urinary excretion of CPZ. LPS significantly decreased the biliary clearance (by approximately 55%) and renal clearance (by approximately 35%) of CPZ. However, no changes in the volume of distribution at steady state for CPZ were observed between the treatment groups. Our findings suggest that LPS induces changes in the pharmacokinetics of CPZ as a result of changes occurring in the biliary secretory system.

The influence of chronic lobular hepatitis on pharmacokinetics of cefoperazone—a novel galactose single‐point method as a measure of residual liver function

Cefoperazone is a semisynthetic cephalosporin antibiotic containing a piperazine side chain, which results in antipseudomonal activity. Unlike the other cephalosporins, it is mainly cleared by the liver (60-80%) and it may be more sensitive to changes in the liver function and/or plasma protein binding than other cephalosporins, which are not primarily cleared by the liver. In order to study the influence of chronic lobular hepatitis on the pharmacokinetics of cefoperazone, a dose of 1 g of cefoperazone was administered to 11 normal, healthy volunteers and 16 subjects with chronic lobular hepatitis. In each volunteer or patient, a novel galactose single-point (GSP) method, the galactose elimination capacity (GEC) test, and the modified galactose elimination capacity (MGEC) test were also performed as a measure of residual liver function. Cefoperazone was administered intravenously over a period of 3-5 min. Blood and urine samples were collected at appropriate intervals after drug administration and stored at -30 degrees C until high-pressure liquid chromatographic (HPLC) analysis. The cefoperazone hepatic clearance, mean residence time, and renal clearance in hepatitis patients were significantly different from those of normal healthy volunteers, whereas the plasma protein binding was unaltered between the two groups. Urinary excretion of cefoperazone showed a highly significant increase in patients, 23.95 +/- 5.06% and 37.54 +/- 13.61% for normal men and hepatitis patients respectively. Hepatic clearance and fraction excreted in urine significantly correlated with values of GSP and MGEC respectively (p < 0.05). These results suggest (i) cefoperazone kinetics was significantly altered in patients with chronic lobular hepatitis; (ii) GSP, a novel simple, clinically useful quantitative liver function test, can predict the cefoperazone hepatic clearance in patients with liver dysfunction.

Effect of impaired renal function on the pharmacokinetics of coadministered cefoperazone and sulbactam.

The pharmacokinetics of cefoperazone 2 g combined with sulbactam 1 g after a single dose administered intravenously were evaluated in 24 subjects with normal and impaired renal function. Subjects were categorized into four groups based on endogenous creatinine clearance Clcr. Patients in groups 1, 2 and 3 had ClcrS of greater than 60, 31 to 60, and 10 to 30 mL/min/1.73 m2, respectively. Patients in group 4 required maintenance haemodialysis and were assumed to have Clcr less than 10 mL/min/1.73 m2. Pharmacokinetic parameters were determined by noncompartmental methods. No significant differences (P greater than 0.05) in mean peak serum cefoperazone-sulbactam concentrations for group 1 (208.4/29.0 mg/L), group 2 (199.0/34.1 mg/L), group 3 (163.2/35.0 mg/L), and group 4 (234.0/66.0 mg/L) were noted. Correlations between both total serum (r = 0.58) and renal (r = 0.35) clearance and creatinine clearances were negative for cefoperazone, although both were shown to decline with diminished renal function. Correlations between serum (r = 0.85) and renal (r = 0.72) clearances and creatinine clearance for sulbactam were, on the other hand, both positive and declined in a linear fashion. No significant differences in steady state volumes of distribution were noted for either cefoperazone (P = 0.53) or sulbactam (P = 0.85) amongst the four groups. After 24 h, urinary recovery was also comparable for both cefoperazone (P = 0.64) and sulbactam (P = 0.85) amongst the four groups. The concentrations of cefoperazone and sulbactam remained at or above the MICs (16/8 mg/L) for common bacterial pathogens for 2.5, 3, 7 and 14 h in groups 1, 2, 3 and 4, respectively.

Penetration of cefoperazone into ascites

The pharmacokinetics of cefoperazone was studied in eleven cirrhotic patients with ascites after i.v. administration of a single dose of 15 mg.kg-1 (n = 7) or after three doses of 15 mg.kg-1 given at 12 h intervals (n = 4). The concentrations of cefoperazone in serum and ascitic fluid were determined by HPLC. The peak serum cefoperazone concentration after a single i.v. injection of 15 mg.kg-1 was 96.0 mg.l-1. The serum elimination half-life was longer (5.0 h) than in normal subjects. The penetration of cefoperazone into ascites was satisfactory (32.3% and 58.3% after single and repeated injections, respectively). Ascitic fluid concentrations of cefoperazone exceeded 5.4 mg.ml-1 from 0.5 to 6 h after the single i.v. injection, levels which are well above the MIC of most pathogens found in spontaneous bacterial peritonitis. Adjustment of the dose of cefoperazone in cases of severe hepatic insufficiency does not appear to be necessary provided that renal function is normal.

Pharmacokinetics of single doses of cefoperazone given by the intravenous and intramuscular routes to unweaned calves

Cefoperazone pharmacokinetics were studied in unweaned calves. The antibiotic was administered to 10 calves intravenously, to eight calves intramuscularly at 20 mg kg-1 and to 10 calves intramuscularly at 20 mg kg-1 together with probenecid at 40 mg kg-1. Serum concentration versus time data were analysed by non-compartmental methods based on the statistical moment theory. The intravenous data were also fitted by a linear, open two-compartment model. The terminal halflife of cefoperazone was 127.9 +/- 28.2 min (mean +/- SD) after intravenous and 136.9 +/- 19.6 min after intramuscular administration. The t1/2 was increased to 257.3 +/- 127.3 min by the co-administration of probenecid. The total body clearance was 8.16 +/- 1.60 ml min-1 kg-1 and the volume of distribution at steady state was 0.713 +/- 0.167 litre kg-1. The mean residence time values were 87.2 +/- 10.6 min after intravenous and 140.3 +/- 20.6 min after intramuscular injection and were increased to 264.5 +/- 99.8 min by the co-administration of probenecid. The estimated mean absorption time was 53.1 min and the estimated bioavailability after intramuscular administration was 76.3 per cent. The minimal inhibitory concentration (MIC90) values of cefoperazone ranged from 0.5 to 2 micrograms ml-1 for Escherichia coli, salmonella groups C, D and E and Pasteurella multocida isolates. Salmonella group B strains appeared to be highly resistant to cefoperazone with MIC90 greater than 32 micrograms ml-1. There were no significant differences between the pharmacokinetic variables calculated by statistical moment theory or compartmental analysis indicating central compartment output of cefoperazone.(ABSTRACT TRUNCATED AT 250 WORDS)

Multiple-dose pharmacokinetics of intravenously administered cefoperazone and sulbactam when given in combination to infected, seriously ill, elderly patients.

The pharmacokinetics of cefoperazone and sulbactam in combination were evaluated in six, elderly, seriously ill patients treated with the drug combination for intra-abdominal infections. After giving informed consent, three males and three females aged 63.5 to 77.5 (mean 67.9) years and weighing 54.5 to 86.8 (mean, 67.6) kg were treated with cefoperazone (2.0 g) and sulbactam (1.0 g) infused intravenously every 12 h for at least 5 days. Cefoperazone and sulbactam pharmacokinetics were characterized on both days 1 and 5 of treatment. Eleven serial blood samples were obtained just prior to and following dose 1 on days 1 and 5 of treatment. Mean estimates of cefoperazone maximal concentration in plasma (Cmax), area under the curve of drug concentration in plasma versus time (AUC), half-life (t 1/2), apparent volume of distribution by the area method (Varea), apparent volume of distribution at steady state (Vss), and total body clearance (CL) for day 1 (day 5) were 297.5 237.5) micrograms/ml, 1,247 (1,063) micrograms.h/ml, 7.0 (4.9) h, 16.1 (13.4) liter, 13.1 (14.4) liter, and 28.9 (34.2) ml/min, respectively. Day 1 (day 5) mean values for sulbactam Cmax, AUC, t 1/2, Varea, Vss, and CL were 110.3 (78.0) micrograms/ml, 228 (217) micrograms.h/ml, 3.4 (2.5) h, 26.1 (18.5) liter, 18.9 (15.4) liter, and 97 (94) ml/min, respectively. Both drugs evidenced slower elimination and greater pharmacokinetic variability in these patients compared with values previously reported for normal volunteers. As patients improved during the course of therapy, the only pharmacokinetic parameter significantly changed between days 1 and 5 was a shortened sulbactam t 1/2. Our inability to find substantial evidence of pharmacokinetic normalization may have been related to sample size and study duration. Both drugs were present in potentially therapeutic concentrations for the entire 12-h dosing interval, but without undue accumulation from days 1 to 5.

Pharmacokinetics of cefoperazone in the cow by the intramammary route and its effect on mastitis pathogens in vitro.

The pharmacokinetic and microbiological properties of a new third generation cephalosporin, cefoperazone, when given by the intramammary route to the cow are described. Cefoperazone is excreted from the udder over a three- to five-day period following a single infusion of 250 mg in an oil base into each of all four quarters. By the fifth milking after treatment the mean bucket (composite) concentration of cefoperazone was below 0.01 microgram/ml. The minimal inhibitory concentrations for 470 pathogens isolated from cases of mastitis were determined. A few exotic species were resistant but all the usual isolates were sensitive. No signs of transferable drug resistance from known multiple drug-resistant strains were detected.

Pharmacokinetic evaluation of cefoperazone in infants.

The pharmacokinetics of cefoperazone were evaluated in 25 infants (mean age, 26 days) after intramuscular and intravenous routes of administration. The levels in blood that were achieved were severalfold higher than those required to inhibit common pathogens. The mean half-life of 240 min was one-half of that observed in 1- to 2-day-old infants but about twice that seen in adults. Further evaluation is needed to study the efficacy of the drug in infants and children.

Cefoperazone therapy of complicated urinary tract infections: pharmacokinetics in renal transplant recipients.

Cefoperazone was used to treat patients with complicated urinary tract infections due to multiple antibiotic-resistant gram-negative rods who had failed prior courses of intravenous antibiotic therapy. Cure was achieved in 44% (4/9) of cases; 44% of patients improved but relapsed and 11% (1/9) of patients were reinfected. Relapse and reinfection were associated with Pseudomonas aeruginosa and/or with conditions not normally responsive to medical therapy alone including prostatitis, reflux and chronic indwelling Foley catheters. The pharmacokinetics of cefoperazone were studied in renal transplant recipients. Peak serum concentrations (range 146-241 micrograms/ml) and 2-hour noncumulative urine concentrations (range 161-291 micrograms/ml) exceeded the minimal inhibitory concentrations of the bacteria in all cases. There was no accumulation of cefoperazone despite the presence of impaired renal function.

Pharmacokinetics of multiple-dose cefoperazone in hemodialysis patients.

We studied the pharmacokinetics of cefoperazone 2 g i.v. every 12 h for 7 days in 12 patients on hemodialysis with normal hepatic function. The half-life of indocyanine green was determined in each patient via ear oximetry. Serum levels of cefoperazone during dialysis were well described by a two-compartment multidose infusion model. From this model we determined the steady state volume of distribution (Vdss), elimination phase half-life during dialysis T1/2D) and off hemodialysis (T1/2), and the corresponding elimination rate constants (KeD and Ke). Multiple correlations between pharmacokinetic parameters, liver function, and physical characteristics of the patients were evaluated. The T1/2 of cefoperazone was 2.9 h off compared to 2.3 h during hemodialysis. The corresponding elimination rate constants were Ke = 0.45/h versus KeD = 0.80/h. Cefoperazone clearances were 78 ml/min off dialysis compared to 140 ml/min during hemodialysis. Vdss was 0.20 liters/kg. The indocyanine green half-life ranged from 1.8 to 4.6 min with a mean of 2.7 min. The ages of the patients correlated with the beta phase half-life (r = 0.68, p = 0.015). We found no significant correlations among the other parameters including hepatic enzymes and indocyanine green half-life. Thus, hemodialysis approximately doubles the elimination rate constant (clearance), but, assuming drug redistribution kinetics remain unchanged, only shortens half-life by about 20%. Scheduling of a 12-hour dosing regimen to coincide with the end of hemodialysis should obviate any need for alteration of dose. Cefoperazone is thus unique among cephalosporins, since the half-life does not change appreciably with end-stage renal disease or dialysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of cefoperazone in patients undergoing chronic ambulatory peritoneal dialysis: clinical and pathophysiological implications.

The pharmacokinetics of cefoperazone after i.p. and/or i.v. administration were studied in 12 CAPD patients. After i.v. injection, the plasma half-life was 2.65 +/- 0.4 h, the total clearance amounting to 70.1 +/- 19.2 ml/min. Peritoneal clearance was calculated to be 6.9 +/- 1 ml/min. After peritoneal instillation, the bioavailability was 63.9 +/- 5%. After repeated i.p. administration, no accumulation of the drug in the body was observed. Thus, cefoperazone can be safely administered for the treatment of peritonitis in CAPD patients.

Pharmacokinetics of cefoperazone in full-term and premature neonates.

The pharmacokinetics of cefoperazone were evaluated in 28 newborn infants who were being treated for sepsis. A dose of 50 mg/kg was administered intravenously on days 0 to 2 in all, with a second dose administered on days 5 to 7 in 14 infants. Cerebrospinal fluid penetration was also studied in seven neonates. The mean peak concentration of cefoperazone in the serum of premature infants less than 33 weeks of gestational age, 159 (standard deviation, +/- 22) micrograms/ml, was higher than concentrations in premature infants 33 to 36 weeks of age and full-term infants (110 +/- 41 and 109 +/- 29 micrograms/ml, respectively). The mean concentrations 24 h after dosage were similar in all three groups, 13 to 17 micrograms/ml. The mean serum half-lives were similar in the three subgroups and ranged from 7 to 9 h. After the dose at 5 to 7 days, mean blood levels in the subgroups at 0.5 h were 149, 112, and 112 micrograms/ml; 24-h levels ranged from 9 to 12 micrograms/ml. The mean serum half-lives ranged from 5 to 7 h. Cerebrospinal fluid levels in patients with meningitis ranged from 2.8 to 9.5 micrograms/ml and in patients without meningitis from 1 to 7 micrograms/ml. Peak blood levels were 15 to 1,000 times higher than the 90% minimal inhibitory concentration of common pathogens found in newborns. These observations support the potential efficacy of cefoperazone in treatment of infections, including meningitis, in newborn infants.

Pharmacokinetics of cefoperazone in patients with normal and impaired hepatic and renal function.

The pharmacokinetics of cefoperazone in normal subjects and in patients with hepatic and renal dysfunction are reviewed. Peak serum concentrations and areas under serum level-time curves are linearly related to dose. The range of mean peak serum concentrations after a 2-g dose of cefoperazone is 202-375 micrograms/ml with iv injection or infusion and 111 micrograms/ml with im injection. The serum half-life is 1.6-2.6 hr. Urinary excretion is rapid, but only 15%-37% of the dose is recovered in urine. The drug is not metabolized significantly. Levels of drug in bile are many times higher than serum levels, and biliary excretion represents the major pathway of cefoperazone elimination. Serum kinetics of cefoperazone are not significantly altered by renal impairment. However, hepatic dysfunction is associated with a two- to fourfold increase in serum half-life. Even in these patients, drug accumulation was not observed after repeated administration of 1 g of cefoperazone at 12-hr intervals. Major dosage modification should only be required with concomitant renal and hepatic dysfunction.