Steady-state pharmacokinetics and pharmacodynamics of piperacillin and tazobactam administered by prolonged infusion in obese patients.

The study objective was to evaluate steady-state pharmacokinetics and pharmacodynamics of piperacillin and tazobactam administered by prolonged infusion in obese patients. Fourteen hospitalised patients weighing >120kg received piperacillin/tazobactam 4.5 g every 8 h (q8h) or 6.75 g q8h infused over 4h. Blood samples were collected at steady-state and drug concentrations were determined. Pharmacokinetic parameters were estimated and 5000-patient Monte Carlo simulations were performed for four prolonged-infusion dosing regimens. The probability of target attainment (PTA) for ≥50% fT>MIC was calculated for piperacillin at various MICs, and the PTA for fAUC(0-24)≥96 mg h/L was calculated for tazobactam. Mean±S.D. patient demographics were: age 49±10 years; weight 161±29 kg; and body mass index 52.3±10.8 kg/m(2). For piperacillin and tazobactam, respectively, the mean±S.D. elimination rate was 0.440±0.177 h(-1) and 0.320±0.145 h(-1), volume of distribution was 33.4±14.0L (0.21±0.07L/kg) and 37.5±15.3L (0.23±0.08 L/kg), and systemic clearance was 13.7±5.2L/h and 11.1±4.2L/h. For piperacillin, the PTA was ≥91% for doses ≥4.5g q8h at MICs≤16 μg/mL. For tazobactam, the PTA was 57%, 84% and 94% for doses of 4.5, 6.75 and 9.0g q8h, respectively. The pharmacokinetics of piperacillin and tazobactam are altered in obese patients. To ensure adequate tazobactam concentrations for β-lactamase inhibition, it may be prudent to employ larger initial doses for empirical therapy in obese patients.

Cheatham SC ，Fleming MR ，Healy DP ，Chung CE ，Shea KM ，Humphrey ML ，Kays MB ... -  《-》

Population pharmacokinetics and pharmacodynamics of piperacillin and tazobactam administered by prolonged infusion in obese and nonobese patients.

The study objective was to evaluate the population pharmacokinetics and pharmacodynamics of piperacillin and tazobactam administered by prolonged infusion in obese and nonobese patients. Twenty-seven patients (total body weight [TBW], 60 to 211 kg; body mass index [BMI], 19.6 to 72.9 kg/m(2) ) received 4.5 or 6.75 g every 8 hours, infused over 4 hours, and serum concentrations were measured at steady state. Population pharmacokinetic parameters were estimated using NONMEM, and Monte Carlo simulations were performed for three 4-hour dosing regimens to calculate probability of target attainment (PTA) at ≥50% fT>MIC.A 1-compartment linear-elimination model best fit the pharmacokinetic data for piperacillin and tazobactam. Creatinine clearance (CRCL), TBW, and BMI were significantly associated with piperacillin pharmacokinetics, and CRCL was significantly associated with tazobactam pharmacokinetics. Clearance and volume of distribution for piperacillin and tazobactam were significantly different between obese and nonobese patients (P < .05). At MICs ≤ 16 mg/L, PTA was >90% for dosing regimens ≥3.375 g every 8 hours in nonobese patients and ≥ 4.5 g every 8 hours in obese patients. Piperacillin and tazobactam pharmacokinetics are altered in obesity, and 4.5 g every 8 hours infused over 4 hours should be recommended for empiric therapy in obese patients.

Chung EK ，Cheatham SC ，Fleming MR ，Healy DP ，Shea KM ，Kays MB ... -  《-》

Steady-state pharmacokinetics and pharmacodynamics of piperacillin/tazobactam administered by prolonged infusion in hospitalised patients.

Shea KM ，Cheatham SC ，Wack MF ，Smith DW ，Sowinski KM ，Kays MB ... -  《-》

Comparative pharmacodynamics of intermittent and prolonged infusions of piperacillin/tazobactam using Monte Carlo simulations and steady-state pharmacokinetic data from hospitalized patients.

Shea KM ，Cheatham SC ，Smith DW ，Wack MF ，Sowinski KM ，Kays MB ... -  《-》

Pharmacokinetics and pharmacodynamics of extended-infusion piperacillin/tazobactam in adult patients with cystic fibrosis-related acute pulmonary exacerbations.

Butterfield JM ，Lodise TP ，Beegle S ，Rosen J ，Farkas J ，Pai MP ... -  《-》