Pharmacokinetics of intravenous and intraperitoneal ceftazidime in chronic ambulatory peritoneal dialysis

Pharmacokinetic analysis of ceftazidime and cefazolin in the treatment of continuous ambulatory peritoneal dialysis-related peritonitis

OBJECTIVE

Peritoneal dialysis-related peritonitis (PDRP) presents a significant challenge for nephrologists. Continuous intraperitoneal cefazolin and ceftazidime are recommended for the treatment of peritonitis. However, some pharmacokinetic studies have shown that doses of 15-20 mg/kg/d may not achieve sufficient therapeutic levels. In this study, we investigated the pharmacokinetics of ceftazidime and cefazolin in patients with continuous ambulatory peritoneal dialysis-related peritonitis and compared the pharmacokinetic characteristics between traditional and modified treatment groups.

METHODS

From February 2017 to December 2019, 42 PDRP patients (17 males, 25 females; mean age: 50.7 ± 12.1 years; mean body weight: 60.9 ± 11.8 kg) were recruited for the study, all participants were anuric. Twenty patients were enrolled in the traditional group and treated with cefazolin (1.0 g) and ceftazidime (1.0 g) via intraperitoneal administration once daily for 14 days. Twenty-two patients were enrolled in the modified group and received the same dose of antibiotics twice daily for the initial five days, followed by once daily for the subsequent nine days. Serum and dialysate samples were collected after days 1, 2, 3, 5, 7, 10, and 14 and analyzed via liquid chromatography-mass spectrometry.

RESULTS

In the traditional group, the highest and lowest serum concentrations of ceftazidime were 35.9 and 21.7 µg/mL, respectively. The highest concentration of cefazolin was 54.6 µg/mL on day 5 and the lowest concentration was 30.4 µg/mL on day 1. In the modified group, the highest and lowest serum concentrations of ceftazidime were 102.2 and 54.8 µg/mL, respectively. The highest concentration of cefazolin was 141.7 µg/mL and the lowest concentration was 79.8 µg/mL. All antibiotic concentrations were above the minimum inhibitory concentration (MIC) level (8 µg/mL of ceftazidime and 2 µg/mL of cefazolin) throughout the treatment period. However, on day 1, the concentration of ceftazidime in the third bag of dialysate effluent from the traditional group fell below the MIC level. Despite remaining above the MIC, cefazolin concentration was consistently lower in the third bag of dialysate effluent from the traditional group throughout the treatment period.

CONCLUSIONS

Intraperitoneal administration of cefazolin and ceftazidime at a dose of 1 g twice daily for 5 days and then once daily for the rest of the treatment period ensured adequate therapeutic levels of antibiotics for treating anuric PDRP patients.

Pharmacokinetics of Ceftazidime in CAPD-Related Peritonitis

Objective

The aim of this study was to measure and evaluate the appropriateness of the actual concentrations of serum and dialysate ceftazidime in Thai continuous ambulatory peritoneal dialysis (CAPD) patients.

Design

Prospective and descriptive study of patients treated following the International Society for Peritoneal Dialysis (ISPD) 2000 recommendation for the empiric therapy of CAPD-related peritonitis.

Setting

Institutional level of clinical care.

Patients

CAPD-related peritonitis patients were diagnosed by dialysate effluent white blood cell count of more than 100/mm3and polymorphonuclear leukocytes of at least 50%. There were 10 patients, all at least 18 years of age, entered; all completed the study.

Intervention

In accordance with the ISPD 2000 recommendations, the antibiotic regimen comprised continuous intraperitoneal (IP) cefazolin and once-daily IP ceftazidime. Cefazolin was administered as loading and continuous maintenance doses of 500 and 125 mg/L dialysate respectively. Ceftazidime (20 mg/kg body weight) was given IP once daily. Duration of treatment was 96 hours.

Main Outcome Measures

Serum and dialysate effluent samples of the 10 CAPD patients with peritonitis were measured for ceftazidime levels, which were used for the development of pharmacokinetic equations that could predict drug concentrations at any treatment time.

Results

Following ceftazidime administration as in the ISPD 2000 recommendation, serum ceftazidime levels were above 8 μg/mL, the minimum inhibitory concentration (MIC) recommended by NCCLS, throughout 24 hours. Dialysate ceftazidime levels were below the MIC for total periods of 4.19 and 6.26 hours in day 1 and day 4 respectively. The clinical response rate to the empiric regimen was 90%.

Conclusions

Once-daily IP administration of ceftazidime according to the ISPD 2000 recommendation could not provide adequately therapeutic levels of ceftazidime in dialysate throughout 24 hours. Despite this finding and the poor post-antibiotic property of ceftazidime, the empiric regimen including once-daily IP ceftazidime could yield good clinical outcome.

Reevaluation of ceftazidime dosing recommendations in patients on continuous ambulatory peritoneal dialysis

While intraperitoneal (i.p.) ceftazidime is commonly used to treat continuous ambulatory peritoneal dialysis (CAPD)-related infections, the ability of i.p. regimens to achieve critical pharmacodynamic targets in both blood and dialysate has not been reported. To understand the pharmacodynamic profile of ceftazidime during CAPD, data were obtained from a single-dose pharmacokinetic (PK) i.p. ceftazidime study that included 10 CAPD patients who received i.p. ceftazidime at 15 mg/kg of body weight. The probability of target attainment (concentrations maintained above the MIC for >60% of the dosing interval [60% T > MIC]) was determined for six simulated regimens. A 3-compartment model with each dialysis dwell modeled as a separate differential equation was fit to ceftazidime concentrations using BigNPAG. Embedded with the final PK model, serum and dialysate concentration-time profiles of ceftazidime at 1, 1.5, and 2 g i.p. every 24 h (q24h) to q48h were simulated using ADAPT 5. The mean population pharmacokinetic parameters were as follows: apparent volume of the central compartment (Vc), 7.57 liter; apparent volume of the peritoneal cavity (Vpd), 2.44 liter; clearance from the central compartment (CL), 0.379 liter/h; intercompartmental transfer rate constants (first order) between the central and peripheral compartments (k12 and k21), 4.66 and 4.88 h(-1), respectively; and intercompartmental transfer rate constants (first order) between the central and peritoneal compartments (k13 and k31), 0.111 and 0.227 h(-1), respectively. In serum, the probability of target attainment for MICs of ≤8 mg/liter exceeded 90% for 1.5 to 2 g i.p. q24h to q48h. However, no tested regimen provided adequate dialysate exposure at MICs of ≥8 mg/liter on day 1 without the use of a 3-g loading dose (post hoc analysis). On day 2, 1.5 to 2 g i.p. q24h or 2 g i.p. q48h provided adequate exposure in the peritoneal cavity. These results should be validated in the presence of infection. Ceftazidime i.p. at 1.5 or 2 g q24h to q48h is recommended for nonperitoneal infections. For peritonitis, a 3-g load with maintenance dosing of 1 to 2 g i.p. q24h or 2 g i.p. q48h is recommended.

Pharmacokinetic profiles of ceftazidime after intravenous administration in patients undergoing automated peritoneal dialysis

The pharmacokinetics (PK) of ceftazidime after intravenous (i.v.) administration during automated peritoneal dialysis (APD) and their dependence on peritoneal membrane transport are the targets of the present study. Eleven patients receiving a single i.v. dose of ceftazidime (15 mg/kg of body weight) (seven males, median [interquatile] age, 59 [36 to 62]) were recruited. Serum and dialysate samples were collected at the beginning, middle, and end of each of the five dwells during a 24-h period, with dwells 1, 2, and 3 using an automated cycler (designated on-cycler) and dwells 4 and 5 being manual exchanges (designated off-cycler), together with urine collection during the same period. Population PK analysis was employed to estimate the PK parameters. Peritoneal equilibration tests were performed for all patients, and correlations between peritoneal clearance (CL(PD)) for ceftazidime and dialysate-to-plasma ratios for creatinine (D/P(cr)) were obtained using the Spearman's product correlation coefficient (ρ). Ceftazidime renal clearance (CL(renal)) was 0.052 ml/min/kg, and CL(PD) was 0.063 ± 0.050 ml/min/kg. CL(PD) for on- and off-cycler were 0.071 and 0.058 ml/min/kg (P = 0.164), respectively. A significant correlation between CL(PD) and D/P(cr) was observed, with one outlier excluded, suggesting that CL(PD) for ceftazidime during APD is dependent upon the peritoneal small-solute transport rate. A model prediction yielded adequate serum and dialysate concentrations of ceftazidime throughout a 24-h period for sensitive organisms (MIC, 8 μg/ml) by either i.v. (at 15 mg/kg) or intraperitoneal (i.p.; at 20 mg/kg) administration during off-cycler dwells. The present study suggests that the i.v. administration of ceftazidime at 15 mg/kg or i.p. administration of ceftazidime at 20 mg/kg during a long dwell every 24 h can be recommended for treating systemic or intraperitoneal infections of APD patients.

Ceftazidime overdose-related nonconvulsive status epilepticus after intraperitoneal instillation

We report a case of ceftazidime-related nonconvulsive status epilepticus (NCSE) in a 70-year-old female patient with continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis. She was given ceftazidime intravenously which was then changed to intraperitoneal installation after clinical improvement. She received 11 g of ceftazidime via intraperitoneal installation for two days after being discharged from the hospital. Her consciousness was altered with mutism, asterisxis, and horizontal nystagmus. Her EEG showed continuous generalized three spikes-and-wave per second that were abolished after intravenous diazepam. Ceftazidime-related NCSE was suggested and ceftazidime therapy was stopped. Hemodialysis was done while phenytoin was also given to control the convulsions. Her consciousness improved after hemodialysis. Serum ceftazidime measured before and after hemodialysis on the second and third day were 105.2/39.4, 36.2/5.2 microg/mL (normal peak level 55 microg/mL), respectively. Repeated evaluation on day 6 showed normal EEG without epileptiform activity. She was later discharged with full recovery.

Disposition of Ceftazidime After Intraperitoneal Administration in Adolescent Patients Receiving Continuous Cycling Peritoneal Dialysis

BACKGROUND

Peritonitis is the single most common complication in children maintained on continuous cycling peritoneal dialysis (CCPD) and a significant cause of morbidity. Recent consensus guidelines for the treatment of peritonitis in children receiving peritoneal dialysis recommend the combined intraperitoneal administration of ceftazidime with either a first-generation cephalosporin or vancomycin. The objective of this study is to determine whether a continuous maintenance dose of intraperitoneal ceftazidime in the absence of a loading dose would maintain adequate serum and dialysate concentrations to be effective in the treatment of peritonitis.

METHODS

Five ambulatory patients on CCPD therapy were studied with continuous intraperitoneal administration of ceftazidime (125 mg/L). Blood, dialysate, and urine samples were collected at specified intervals during a 24-hour period. Ceftazidime concentrations were measured by using a high-performance liquid chromatography assay.

RESULTS

Mean serum concentrations at completion of the short rapid cycles and at 24 hours were 28.92 +/- 13.64 and 23.92 +/- 11.93 microg/mL, respectively. Serum bioavailability at 24 hours was 74% +/- 6%. Mean dialysate concentrations at completion of the short rapid cycles and at 24 hours were 87.43 +/- 19.18 and 32.06 +/- 6.27 microg/mL, respectively. All 5 patients achieved serum and dialysate ceftazidime concentrations greater than the mean inhibitory concentration within 4 hours.

CONCLUSION

In adolescent patients on CCPD therapy, a continuous maintenance dose of intraperitoneal ceftazidime in the absence of a loading dose achieves serum and dialysate levels greater than the mean inhibitory concentration of sensitive organisms within 4 hours that persist for 24 hours.

Pharmacokinetics of intraperitoneal cefazolin and ceftazidime coadministered to CAPD patients

PURPOSE

Guidelines for empiric treatment of PD-related peritonitis published in 2000 recommend concurrent intraperitoneal (IP) cefazolin and ceftazidime. The pharmacokinetics (PK) of these agents combined have not been studied. This study was designed to determine the PK of combined IP cefazolin and ceftazidime in CAPD patients.

DESIGN

Prospective PK study in seven non-infected CAPD patients.

PROCEDURES

Patients had a peritoneal equilibration test (PET), then received one IP dose of cefazolin and ceftazidime (15 mg/kg each) co-administered over a 4-hour dwell, then performed three CAPD exchanges over the next 16 hours. Serum and dialysate samples collected over the 20-hour study period were assayed for drug concentrations by HPLC.

OUTCOME MEASURES

PK parameters.

STATISTICAL METHODS

Correlations were tested between PET and PK parameters using the Pearson-product correlation coefficient.

MAIN FINDINGS

Serum cefazolin and ceftazidime levels exceeded the minimum inhibitory concentrations for susceptible organisms (8 mg/L) throughout the 20 hour study period. Mean cefazolin and ceftazidime PK parameters included: bioavailability, 71% and 63%; elimination rate constant, 0.031 and 0.045 h -1 ; total clearance, 5.8 and 16.0 ml/min; peritoneal clearance, 1.6 and 3.9 ml/min; renal clearance, 2.3 and 3.9 ml/min, respectively. Predictive equations suggest that 1000 mg IP of cefazolin and of ceftazidime every 24 hours would produce average steady-state trough serum cefazolin and ceftazidime concentrations of 70 +/- 52 mg/L and 17 +/- 7 mg/L, respectively. There was no correlation between PET and PK parameters.

CONCLUSIONS

Co-administration did not adversely affect the PK of either agent. IP cefazolin and ceftazidime (15 mg/kg) produced adequate serum and dialysate concentrations in CAPD patients for 20 hours. PK predictions suggest that most patients would achieve adequate cefazolin and ceftazidime concentrations with 1000 mg IP once-daily. Anuric patients and those with significant residual renal function may require a more individualized approach.

Infections in patients undergoing peritoneal dialysis

Considering experience acquired in the past years, it seems as though physicians have reached a plateau in the frequency of peritonitis. A peritonitis rate of 1 every 2 patient years may be acceptable. Further reduction of this peritonitis rate will require inordinately large efforts on all fronts. One will have to consider what are the acceptable costs and risks of peritonitis in patients on peritoneal dialysis. New developments in catheter technology, improved connections, better understanding of patient selection and training programs, improved diagnostic and therapeutic methods in the management of peritonitis, and understanding of the infectious and immune processes are eagerly awaited developments.

Intermittent versus continuous intraperitoneal glycopeptide/ceftazidime treatment in children with peritoneal dialysis-associated peritonitis. The Mid-European Pediatric Peritoneal Dialysis Study Group (MEPPS)

Intermittent intraperitoneal antibiotic administration appears as a practical and economical therapeutic concept in continuous peritoneal dialysis (CPD)-related peritonitis, but the equivalence of this principle with standard continuous treatment awaits confirmation by prospective, randomized clinical trials. This study evaluates the efficacy, safety, and clinical acceptance of an initial combination treatment including a glycopeptide (vancomycin or teicoplanin) and ceftazidime, each applied either intermittently or continuously, in a cohort of pediatric patients with CPD-related peritonitis. Patients randomized for continuous treatment received an intraperitoneal loading dose of glycopeptide and ceftazidime followed by maintenance doses added to each dialysate bag. In the intermittent treatment groups, the glycopeptide was administered in two loading doses 7 d apart, and ceftazidime during one dialysis cycle per day. Initial treatment response was evaluated after 60 h by the change in a Disease Severity Score and by the clinical decision to continue initial treatment. Of 152 patients observed for a total of 234 patient years, 90 patients developed 195 episodes of peritonitis (including 27 relapses within 4 wk after end of treatment). Dialysate cultures were positive in 83% of the episodes. In gram-positive peritonitis (79% of culture-positive cases), the primary success (overall 95%) and relapse rates (21%) were not different between continuous and intermittent, or between vancomycin and teicoplanin treatment. Oversensitivity reactions occurred in three and ototoxicity in one vancomycin-treated patient, whereas no such side effects were observed with teicoplanin. Residual renal function declined during peritonitis episodes regardless of treatment modality. In gram-negative peritonitis (18% of cases), intermittent ceftazidime treatment was less successful than continuous treatment according to clinical judgment (3 of 11 versus 10 of 14, P < 0.05), but not when rated by Disease Severity Score (8 of 11 versus 12 of 14). In conclusion, intermittent and continuous intraperitoneal treatment of CPD-related peritonitis with glycopeptides and ceftazidime is equally efficacious and safe when measured by objective clinical criteria. This contrasts with a strong tendency of clinicians to move from intermittent to continuous treatment in severe peritonitis.

Pharmacokinetics of intermittent intraperitoneal ceftazidime

Ceftazidime is currently recommended as an alternative first-line agent in the treatment of peritonitis and for Pseudomonas peritonitis. The pharmacokinetics of intermittent intraperitoneal (i.p.) ceftazidime have been poorly characterized. This study was designed to characterize the pharmacokinetic disposition of a single dose of ceftazidime in anuric and non-anuric CAPD patients, over 48 hours. This was a prospective, open label, pharmacokinetic study. The study was conducted in an independent, outpatient dialysis center. Ten volunteer continuous ambulatory peritoneal dialysis (CAPD) patients with and without residual renal function, no peritonitis or antibiotics in the previous 4 weeks, and on CAPD for at least 2 months were recruited. Patients received a single dose of i.p. ceftazidime (15 mg/kg) in the first daytime exchange over a 6-hour dwell, after an overnight dwell. Serum, urine, and dialysate were collected over a 48-hour period. A high-pressure liquid chromatography (HPLC) assay was used to analyze ceftazidime in these samples. Pharmacokinetic parameters were calculated. Six of the 10 patients were non-anuric with a mean residual renal creatinine clearance of 2.9 +/- 1.6 mL/min. The mean +/- SD bioavailability was 72% +/- 14%, and the volume of distribution was 0.34 +/- 0.08 L/kg. The mean serum elimination half-life of 22 +/- 5 hours. The peritoneal clearance was 5.74 +/- 1.6 mL/min. No difference was detected between anuric and nonanuric patients. Mean plasma and dialysate concentrations at 24 hours were 24 +/- 6 microg/mL and 18 +/- 7 microg/mL, respectively, and were 12.0 +/- 3.6 microg/mL and 7.4 +/- 3.1 microg/mL at 48 hours, respectively. Once-daily i.p. dosing of ceftazidime achieves serum and dialysate levels greater than the MIC of sensitive organisms over 48 hours.