Dose linearity testing of intravenous cefpirome (HR 810), a novel cephalosporin derivate

New Stability Indicating RP-HPLC Method for the Estimation of Cefpirome Sulphate in Bulk and Pharmaceutical Dosage Forms

A simple stability indicating reversed-phase HPLC method was developed and subsequently validated for estimation of Cefpirome sulphate (CPS) present in pharmaceutical dosage forms. The proposed RP-HPLC method utilizes a LiChroCART-Lichrosphere100, C18 RP column (250 mm × 4mm × 5 μm) in an isocratic separation mode with mobile phase consisting of methanol and water in the proportion of 50:50 % (v/v), at a flow rate 1ml/min, and the effluent was monitored at 270 nm. The retention time of CPS was 2.733 min and its formulation was exposed to acidic, alkaline, photolytic, thermal and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. The described method was linear over a range of 0.5-200μg/ml. The percentage recovery was 99.46. F-test and t-test at 95% confidence level were used to check the intermediate precision data obtained under different experimental setups; the calculated value was found to be less than the critical value.

Comparable population pharmacokinetics and pharmacodynamic breakpoints of cefpirome in cystic fibrosis patients and healthy volunteers

Cystic fibrosis (CF) patients are often reported to have higher clearances and larger volumes of distribution per kilogram of total body weight (WT) for beta-lactams than healthy volunteers. As pharmacokinetic (PK) data on cefpirome from studies of CF patients are lacking, we systematically compared its population PK and pharmacodynamic breakpoints for CF patients and healthy volunteers of similar body size. Twelve adult CF patients (median lean body mass [LBM] = 45.7 kg) and 12 healthy volunteers (LBM = 50.0 kg) received a single 10-min intravenous infusion of 2 g cefpirome. Plasma and urine concentrations were determined by high-performance liquid chromatography (HPLC). Population PK and Monte Carlo simulations were performed using NONMEM and S-ADAPT and a duration of an unbound plasma concentration above the MIC ≥ 65% of the dosing interval as a pharmacodynamic target. Unscaled clearances for CF patients were similar to those seen with healthy volunteers, and the volume of distribution was 6% lower for CF patients. Linear scaling of total clearance by WT resulted in clearance that was 20% higher (P ≤ 0.001 [nonparametric bootstrap]) in CF patients. Allometric scaling by LBM explained the differences between the two subject groups with respect to average clearance and volume of distribution and reduced the unexplained between-subject variability of renal and nonrenal clearance by 10 to 14%. For the CF patients, robust (>90%) probabilities of target attainment (PTA) were achieved by the administration of a standard dose of 2 g/70 kg WT every 12 h (Q12h) given as 30-min infusions for MICs ≤ 1.5 mg/liter. As alternative dosage regimens, a 5-h infusion of 1.33 g/70 kg WT Q8h achieved robust PTAs for MICs ≤ 8 to 12 mg/liter and a continuous infusion of 4 g/day for MICs ≤ 12 mg/liter. Prolonged infusion of cefpirome is expected to be superior to short-term infusions for MICs between 2 and 12 mg/liter.

Cefpirome. A review of its antibacterial activity, pharmacokinetic properties and clinical efficacy in the treatment of severe nosocomial infections and febrile neutropenia

Cefpirome is an injectable extended-spectrum or 'fourth generation' cephalosporin. Its antibacterial activity encompasses many of the pathogens involved in hospital-acquired infections such as Enterobacteriaceae, methicillin-susceptible Staphylococcus aureus, coagulase-negative staphylococci and viridans group streptococci. Cefpirome also has in vitro activity against Streptococcus pneumoniae regardless of penicillin susceptibility. It is stable against most plasmid- and chromosome-mediated beta-lactamases, with the exception of the extended-spectrum plasmid-mediated SHV enzymes. Intravenous cefpirome 2g twice daily has shown clinical efficacy comparable to that of ceftazidime 2g 3 times daily in the treatment of hospitalised patients with moderate to severe infections. Clinical response and bacteriological eradication rates were similar in patients with severe pneumonia or septicaemia treated with either cefpirome or ceftazidime. Cefpirome appeared more effective than ceftazidime in the eradication of bacteria in patients with febrile neutropenia in 1 study; however, clinical response rates were similar in the 2 treatment groups. The tolerability of cefpirome appears similar to that of ceftazidime and other third generation cephalosporins, diarrhoea being the most frequently observed event. Thus, cefpirome is likely to be a valuable extended-spectrum agent for the treatment of severe infections. Cefpirome offers improved coverage against some Gram-positive pathogens and Enterobacteriaceae producing class I beta-lactamases compared with the third generation cephalosporins, although this has yet to be demonstrated in clinical trials.

Pharmacokinetics of cefpirome in pediatric patients

Cefpirome is a new investigational cephalosporin. We designed a study to determine the pharmacokinetics and tolerance of cefpirome in pediatric patients. A single dose of cefpirome was administered intravenously over 15 min to 18 patients (age 0.5 to 18 years). The doses were 10 mg/kg of body weight for five patients, 25 mg/kg of body weight for seven patients, and 50 mg/kg of body weight for six patients. Blood samples were collected at 0, 0.25, 0.5, 1, 3, 5, and 8 h after the dose, and cefpirome was measured by a high-performance liquid chromatography method. The maximum concentration in serum ranged from about 53.6 to 454 micrograms/ml after doses of 10 to 50 mg/kg. The total body clearance, apparent volume of distribution, and elimination half-life were 2.15 +/- 0.70 ml/min/kg, 0.32 +/- 0.32 liter/kg, and 1.8 +/- 1.3 h, respectively. No significant adverse effects were attributed to cefpirome. These data may be useful in conducting efficacy and safety studies of cefpirome in pediatric patients.

A review of the adverse events profile of cefpirome

Cefpirome is a new fourth generation injectable cephalosporin antibiotic. Its tolerability profile was established in a programme of 16 clinical studies involving 3103 patients in Europe and the US. The overall incidence of clinical adverse events with cefpirome was 21.9% compared with 27.1% with comparators (ceftazidime, imipenem, ceftriaxone). Adverse events thought possibly related to treatment occurred in 12.5% of patients receiving cefpirome and 13.7% of recipients of comparator agents. Withdrawals from treatment due to adverse events occurred in 5.1 and 5.0% of patients receiving cefpirome and comparators, respectively. The commonest adverse events thought possibly related to treatment were gastrointestinal symptoms (mainly diarrhoea in 1.6 and 1.7%, respectively) and rash (1.4 and 1.4%, respectively). Comparison with data obtained from the literature for ceftazidime, ceftriaxone and the third generation cephalosporins in general shows that the adverse event profile of cefpirome is similar to that of other broad-spectrum injectable cephalosporins.

Cefpirome clinical pharmacokinetics

Cefpirome is a new cephalosporin that exhibits similar in vitro potency to ceftazidime against Gram-negative organisms but has significantly greater in vitro potency against Gram-positive organisms. Cefpirome differs from cefotaxime in that a 3'-pyridinium moiety replaces the acetoxy moiety of cefotaxime. This structural change imparts greater beta-lactamase stability, increases the ability to penetrate the outer membrane of Gram-negative bacteria, and enhances activity against Gram-positive organisms. The pharmacokinetic properties of cefpirome are typical of cephalosporins. The drug can be administered by intravenous or intramuscular injection, but is not well absorbed after oral administration. Bioavailability following intramuscular injection exceeds 90%. Cefpirome exhibits low protein binding (approximately 10%) and has a volume of distribution similar to extracellular fluid volume. Cefpirome penetrates the prostate gland, lung, blister fluid, cerebrospinal fluid and peritoneal fluid, reaching concentrations that are similar to those achieved by other later generation cephalosporins. Approximately 80% of an intravenous dose is eliminated unchanged in the urine. No active metabolites of cefpirome have been identified. The elimination half-life of cefpirome is approximately 2 hours. Elimination appears to be primarily by glomerular filtration since the total clearance of cefpirome is approximately equal to creatinine clearance. The time during which drug concentrations exceed the minimum inhibitory concentration (MIC) represents the most clinically important pharmacodynamic parameter for beta-lactam agents. When cefpirome is administered at a dosage of 2g every 12 hours to patients without renal insufficiency [creatinine clearance 70 ml/min (4.2 L/h)], drug concentrations continuously remain above the MIC for pathogens with MIC values of < or = 2 micrograms/ml. With this dosage regimen, drug concentrations will be above the MIC for a pathogen with an MIC of 4 micrograms/ml for 80% of the dosage interval. The time above MIC for pathogens with an MIC of 8 micrograms/ml is only 60% of the dosage interval.

Comparative study of pharmacokinetics and serum bactericidal activities of cefpirome, ceftazidime, ceftriaxone, imipenem, and ciprofloxacin

We compared the pharmacokinetics and the serum bactericidal activities of cefpirome, ceftazidime, ceftriaxone, imipenem, and ciprofloxacin. Fifteen healthy volunteers received 1 g of cefpirome, ceftazidime, and ceftriaxone intravenously, 500 mg of imipenem-cilastatin intravenously, and 500 mg of ciprofloxacin orally. High-performance liquid chromatographic assays were used to quantitate unchanged antibiotic in plasma and urine. Serum bactericidal activities were determined against six clinical isolates each of Staphylococcus aureus, Enterobacter cloacae, and Pseudomonas aeruginosa by using a modified microdilution method of Reller and Stratton (L. B. Reller and C. W. Stratton, J. Infect. Dis. 136:196-204, 1977). Overall, cefpirome exhibited pharmacokinetics similar to those of ceftazidime: half-life (t1/2), 1.95 h; concentration at 1 h (C1h), 47 to 49 micrograms/ml for both antibiotics. Ceftriaxone displayed the longest t1/2 (7.65 h) and the highest C1h (137.8 micrograms/ml), while we observed the shortest t1/2 (1.05 h) and the lowest C1h (19.85 micrograms/ml) with imipenem. At 1 h, cefpirome and, even more so, imipenem showed significantly better serum bactericidal activities against S. aureus (1:273 and 1:80) than did the other antibiotics (P less than 0.0005; analysis of variance with randomized block design and Bonferroni correction). Against E. cloacae, we observed the highest serum bactericidal titers at 1 h with cefpirome, and this superiority vis-à-vis the other antibiotics tested was maintained for up to 8 h after dosing. Ceftazidime remained the most active agent tested against P. aeruginosa (serum bactericidal activity titers, 1:43 at 1 h) up to 8 h. In summary, the study showed that cefpirome and imipenem provide more potent serum bactericidal activities than do broad-spectrum cephalosporins against S. aureus; thus, both of these antibiotics should be adequate against serious S. aureus infections. In addition, cefpirome appears to be a promising alternative for treatment of infections caused by E. cloacae and P. aeruginosa.

Single- and multiple-dose pharmacokinetics of intravenous cefpirome (HR810) to healthy volunteers

The safety and pharmacokinetics of single and multiple administrations of cefpirome (HR810), a new cephalosporin antibiotic agent with a broad antibacterial spectrum, were studied in healthy male volunteers. The single administration protocols included a 3-minute intravenous injection of 0.5 g or 1 g, and a 1-hour intravenous drip infusion of 0.5 g, 1 g, or 2 g. The multiple administration protocols included nine intravenous injections and 1-hour intravenous drip infusions of 1 g of cefpirome twice a day at intervals of 12 hours. Cefpirome was tolerated, and only a few mild, subjective and hepatic-function side effects were observed. There were no severe abnormalities. The drug concentrations in the plasma and the urine were determined by means of HPLC and bioassay, and the results correlated well (r = 0.99). The pharmacokinetic parameters were calculated using a two-compartment model. The elimination half-life (t1/2 beta) was about 1.7 hours for both intravenous injection and intravenous drip infusion and was not dose-dependent. AUC and Cmax were dose-dependent in this study, although an accumulation due to multiple administrations was not observed, and there were no changes in the pharmacokinetic parameters after the initial and the final administrations. The recovery rate of the unchanged compound in the urine was more than 80% in the 24 hours after a single administration and was the same after multiple administrations. Bioautography did not show any active metabolites in the plasma or the urine. The results, for safety and pharmacokinetics, show that cefpirome can be expected to have excellent clinical efficacy for bacterial infections.

Microanalytical high-performance liquid chromatography assay for cefpirome (HR 810) in serum

We report a microanalytical high-performance liquid chromatography method for quantitation of cefpirome (HR 810) from serum. The drug was extracted from 0.05 ml of serum with 0.2 ml of isopropanol containing beta-hydroxypropyltheophylline, the internal standard. Separations were performed on a C18 column at ambient temperature with detection at 240 nm. The mobile phase consisted of acetate buffer (0.05 M sodium acetate) containing tetrabutylammonium hydroxide and methanol (pH 5.1; 70:30, vol/vol). The method was linear to 500 micrograms of cefpirome per ml and had a sensitivity of 0.6 micrograms/ml. Analytical recovery was greater than 86%, and the between-day coefficient of variation was less than 4.2%. The stability for 1 week at 4 to 8 degrees C and for 30 days at -20 degrees C was documented. Interference with commonly used antibiotics, analgesics, methylxanthines, and anticonvulsants was not found. The small sample volume and ease of preparation make this method suitable for use in pediatric pharmacokinetic investigations of cefpirome.