In vitro and in vivo efficacy of YTR-830H and piperacillin combinations versus beta-lactamase-producing bacteria

Pharmacokinetics and Pharmacodynamics of High-Dose Piperacillin-Tazobactam in Obese Patients

Background and Objective

Standard piperacillin–tazobactam (P-T) dosing may be suboptimal in obesity, but high-dose regimens have not been studied. We prospectively evaluated the pharmacokinetics and pharmacodynamics of standard- and high-dose P-T in obese adult inpatients.

Methods

Those receiving standard-dose P-T with BMI ≥ 30 kg/m² weighing 105–139 kg or ≥ 140 kg were given up to 6.75 g or 9 g every 6 h, respectively. Patients were monitored closely for safety. Elimination phase blood samples were drawn for 28 patients on standard and high doses to calculate the pharmacokinetic values using a one-compartment model. The likelihood of pharmacodynamic target attainment (100% fT > 16/4 mg/L) on various P-T regimens was calculated using each patient’s own pharmacokinetic values.

Results

Piperacillin and tazobactam half-lives ranged from 0.5–10.6 to 0.9–15.0 h, while volumes of distribution ranged from 13.6–54.8 to 11.5–60.1 L, respectively. Predicted dose requirements for target attainment ranged from 2.25 g every 6 h in hemodialysis patients to a 27 g/24-h continuous infusion in a patient with a short P-T half-life. An amount of 4.5 g every 6 h would have met the target for only 1/12 (8%) patients with creatinine clearance ≥ 80 mL/min and 13/28 (46%) for all enrolled patients. One patient (3%) experienced an adverse event deemed probably related to high-dose P-T.

Conclusion

Some patients required high P-T doses for target attainment, but dosing requirements were highly variable. Doses up to 6.75 g or 9 g every 6 h may be tolerable; however, studies are needed to see if high dosing, prolonged infusions, or real-time therapeutic drug monitoring improves outcomes in obese patients.

Clinical trial registration (clinicaltrials.gov)

NCT01923363.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13318-021-00677-1.

Expanded studies of piperacillin/tazobactam formulations: variations among branded product lots and assessment of 46 generic lots

The experience with analyzing the potency of piperacillin/tazobactam generic formulations by a precise multiorganism in vitro assay was expanded to 46 lots (29 manufacturers, 17 countries). Across all generic lots, the range of activity compared with a reference branded lot (RLOT; Zosyn; Wyeth Pharmaceuticals, Philadelphia, PA) was +10% to -42% (average, -16%). Eight lots of Zosyn were also tested with a range of +7 to -19 (average, only -6%), and the reproducibility (13 replicates) of the RLOT assay was confirmed (+/-3%). This ongoing quality assurance project demonstrated wide activity variations in piperacillin/tazobactam generic lots with a consistent trend toward subpotent performance (-16%) compared with the branded product. Generic substitutions within hospital formularies should consider parameters of in vitro activity, in addition to applied chemical analyses and measures of bioavailability to avoid potential adverse clinical consequences.

Tazobactam-piperacillin compared with sulbactam-ampicillin, clavulanic acid-ticarcillin, sulbactam-cefoperazone, and piperacillin for activity against beta-lactamase-producing bacteria isolated from patients with complicated urinary tract infections

The antibacterial activity of tazobactam-piperacillin was compared with that of sulbactam-ampicillin, clavulanic acid-ticarcillin, sulbactam-cefoperazone and piperacillin against beta-lactamase-producing bacteria isolated from patients with complicated urinary tract infections. Tazobactam-piperacillin showed a broad antibacterial spectrum against gram-negative and gram-positive bacteria. The minimum inhibitory concentrations (MIC90) of tazobactam-piperacillin were 6.25 micrograms/ml against Escherichia coli, 1.56 micrograms/ml against Proteus mirabilis, 3.13 micrograms/ml against Proteus vulgaris, 6.25 micrograms/ml against methicillin-susceptible Staphylococcus aureus, and 6.25 micrograms/ml coagulase-negative methicillin-susceptible staphylococci. Against all beta-lactamase-producing bacteria tested the antibacterial activity of tazobactam-piperacillin was at least 4- to 64-fold stronger than that of piperacillin, clavulanic acid-ticarcillin, and sulbactam-ampicillin, and similar to or greater than that of sulbactam-cefoperazone except for E. coli.

Review of piperacillin/tazobactam in the treatment of bacteremic infections and summary of clinical efficacy

One method of resistance to beta-lactam antimicrobials involves production of beta-lactamases, enzymes that render the beta-lactam ineffective. Beta-lactamase inhibitors have been combined with beta-lactam antibiotics to combat beta-lactamase producing organisms. One such agent, piperacillin/tazobactam, has been shown to be safe and effective therapy for infections usually treated with a combination of antibiotics such as polymicrobial and nosocomial infection, and has been used for empiric therapy in cases of serious infection. A survey of the literature shows that piperacillin/tazobactam is a safe and efficacious therapy for bacteremia as well as soft tissue, intra-abdominal, and lower respiratory tract infections. When combined with an aminoglycoside, it is also useful in the treatment of severe nosocomial respiratory infections.

Piperacillin/tazobactam in the treatment of polymicrobial infections

Polymicrobial infections are characterized by the presence of micro-organisms from more than one group of bacteria. Empirical treatment of polymicrobial infections requires an agent active against both anaerobic and aerobic/facultative bacteria. An aminoglycoside used in combination with an anti-anaerobe agent is commonly used to treat polymicrobial infections. However, aminoglycoside nephrotoxicity and treatment failures raise questions about the use of such regimens. Among non-aminoglycoside treatment regimens such as penicillin and cephalosporins, effectiveness has been compromised by bacteria producing extended spectrum beta-lactamases. Cefoxitin shows satisfactory results for treatment of intra-abdominal infections. Other studies have shown good results with imipenem, cefotetan and piperacillin used as single agents. Piperacillin/tazobactam, a new combination broad-spectrum antibiotic and potent beta-lactamase inhibitor, can be used for the treatment of infections caused by piperacillin-sensitive micro-organisms as well as beta-lactamase-producing, piperacillin-resistant organisms. This broad-spectrum activity is appropriate for infections traditionally treated empirically by double or triple antibiotic therapy.

Piperacillin/tazobactam. A review of its antibacterial activity, pharmacokinetic properties and therapeutic potential

Combining tazobactam, a beta-lactamase inhibitor, with the ureidopenicillin, piperacillin, successfully restores the activity of piperacillin against beta-lactamase-producing bacteria. Tazobactam has inhibitory activity, and therefore protects piperacillin against Richmond and Sykes types II, III, IV and V beta-lactamases, staphylococcal penicillinase and extended-spectrum beta-lactamases. However, tazobactam has only species-specific activity against class I chromosomally-mediated enzymes. Resistant organisms include some Citrobacter spp., Enterobacter spp., Serratia spp., Xanthomonas maltophilia and Enterococcus faecium. Consistent with its in vitro activity, preliminary clinical data indicate that the fixed combination of piperacillin/tazobactam (dose ratio 8:1) is effective in the treatment of moderate to severe polymicrobial infections, including intra-abdominal, skin and soft-tissue and lower respiratory tract infections. In limited comparative trials, piperacillin/tazobactam demonstrated equivalent or better efficacy than standard comparator regimens in these infections. Piperacillin/tazobactam in combination with an aminoglycoside was effective in the empirical treatment of fever in patients with neutropenia and compared favourably with ceftazidime in combination with an aminoglycoside, although second-line therapy with a glycopeptide antibiotic may be indicated in unresponsive episodes. Data from phase III trials indicate that piperacillin/tazobactam has a tolerability profile typical of a penicillin agent. Piperacillin/tazobactam provides a broad spectrum of antibacterial activity in a convenient single formulation suitable for use in the treatment of polymicrobial infections. Possible limitations concern its restricted activity against class I beta-lactamases, enzymes that are becoming increasingly important in the nosocomial environment. Combined therapy with an aminoglycoside may be necessary in more serious infections.

Comparative in-vitro activity of piperacillin and piperacillin plus tazobactam towards beta-lactamase producing clinical isolates

The authors evaluated the in-vitro antibacterial activity of piperacillin alone and of piperacillin combined with tazobactam, a new beta-lactamase inhibitor, on 398 clinical isolates, both Gram-positive and Gram-negative. The piperacillin/tazobactam combination was evaluated in the fixed ratio 8:1. The vast majority of the microorganisms tested had reduced susceptibility to piperacillin (minimum inhibitory concentration (MIC) range 0.12- greater than 256 mg/l) due to beta-lactamase production. The following results were obtained: against Haemophilus influenzae, tazobactam was effective in reducing the MICs of piperacillin by 512 fold. The activity of piperacillin/tazobactam was lower against Pseudomonas sp., while some activity was demonstrated against some strains of Klebsiella. Good activity was seen not only against methicillin-susceptible (MS) staphylococci but also against some methicillin-resistant (MR) strains. In the latter, the combination of piperacillin/tazobactam was active only if the strains showed beta-lactamase production. These findings are interesting above all in regard to the synergistic effect demonstrated against MR beta-lactamase producing staphylococci and the Klebsiella-Enterobacter-Serratia (KES) group.