Human plasma pharmacokinetics of thiotepa following administration of high-dose thiotepa and cyclophosphamide.

1988 ◽  
Vol 6 (7) ◽  
pp. 1192-1196 ◽  
Author(s):  
S P Ackland ◽  
K E Choi ◽  
M J Ratain ◽  
M J Egorin ◽  
S F Williams ◽  
...  
Keyword(s):  
Stepwise Regression ◽  
Total Body Clearance ◽  
Linear Functions ◽  
High Dose ◽  
Metabolic Clearance ◽  
Plasma Decay ◽  
Plasma Pharmacokinetics ◽  
Total Body ◽  
Dose Dependent ◽  
Body Clearance

Thiotepa is an established alkylating agent whose pharmacokinetics in standard doses are well defined. In order to ascertain whether dose-dependent variations in pharmacokinetics occur, we have undertaken an analysis of plasma thiotepa levels in 16 patients entered on a phase I-II study of bialkylator chemotherapy. High-dose thiotepa (1.8 to 7.0 mg/kg) and cyclophosphamide (2.5 g/m2) were administered intravenously (IV) on days -6, -4, and -2 followed by autologous marrow reinfusion on day 0. Plasma and urinary thiotepa was assayed by gas chromatography. Biexponential plasma decay curves were seen in ten patients, with a t 1/2 alpha of 10.0 +/- 6.4 minutes, a t 1/2 beta of 174 +/- 61 minutes and a total body clearance of 379 +/- 153 mL/h/kg (mean +/- SD). Six patients displayed monoexponential plasma decay curves with a terminal t 1/2 of 137 +/- 83 minutes and a total body clearance of 440 +/- 195 mL/h/kg. Although there was a trend toward reduced plasma clearance in the three patients treated at the highest dose level, the available data suggest that metabolic clearance mechanisms for thiotepa were not saturated with the doses used in this study. By stepwise regression analysis, linear functions using only 15-minute and four-hour postinfusion plasma levels were derived that correlated closely with area under the plasma concentration X time curves (AUC) (P less than .002). We conclude that high-dose thiotepa results in similar pharmacokinetic values to conventional doses with no apparent dose-dependent variation. The value of specific time points to predict AUC and clearance will require prospective evaluation.

scholarly journals Pharmacokinetics of Intravenous Piperacillin Administration in Patients Undergoing On-Line Hemodiafiltration

2009 ◽  
Vol 53 (8) ◽  
pp. 3266-3268 ◽  
Author(s):  
Kook-Hwan Oh ◽  
Chiweon Kim ◽  
Hankyu Lee ◽  
Hajeong Lee ◽  
Ji Yong Jung ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Total Body Clearance ◽  
Volume Of Distribution ◽  
Pharmacokinetic Parameters ◽  
Recovery Method ◽  
Elimination Half ◽  
On Line ◽  
The Mean ◽  
Total Body ◽  
Body Clearance

ABSTRACT The pharmacokinetic characteristics of piperacillin sodium were studied in five volunteers undergoing on-line hemodiafiltration (HDF). The subjects were given 2 g of piperacillin sodium intravenously over 1 min and placed on on-line HDF for 4 h starting at 60 min after the piperacillin infusion. Noncompartmental models were employed for estimation of the pharmacokinetic parameters, and intradialytic piperacillin clearance was calculated by the recovery method. The mean volume of distribution and the elimination half-life were 0.27 ± 0.13 liter/kg (mean ± standard deviation) and 1.1 ± 0.6 h, respectively. The total body clearance of piperacillin was 0.19 ± 0.08 liter/h/kg. Piperacillin clearance through on-line HDF was 0.11 ± 0.06 liter/h/kg. The mean serum piperacillin concentration was 4.0 ± 1.9 μg/ml at the end of the 4-h on-line HDF session. The concentration of infused piperacillin recovered in the dialysate was 527 ± 236 mg (26.3% ± 11.8%). We suggest the replacement of 500 mg of piperacillin after each on-line HDF session.

High-dose cisplatin with sodium thiosulfate protection.

1985 ◽  
Vol 3 (2) ◽  
pp. 237-244 ◽  
Author(s):  
C E Pfeifle ◽  
S B Howell ◽  
R D Felthouse ◽  
T B Woliver ◽  
P A Andrews ◽  
...  
Keyword(s):  
Renal Damage ◽  
Drug Exposure ◽  
Elimination Rate ◽  
Sodium Thiosulfate ◽  
Volume Of Distribution ◽  
High Dose ◽  
Concurrent Administration ◽  
Neutralizing Agent ◽  
Total Body ◽  
Body Clearance

Nephrotoxicity frequently limits the dose of cisplatin to less than 120 mg/m2 per injection. Sodium thiosulfate is a neutralizing agent for cisplatin that protects against renal damage. To determine whether injection of thiosulfate would permit larger doses of cisplatin to be administered, a fixed 9.9-g/m2 dose of thiosulfate was given intravenously over three hours concurrently with escalating doses of cisplatin. Cisplatin was administered over the last two hours of the thiosulfate infusion. Using this technique, it was possible to escalate the cisplatin dose to 225 mg/m2 before dose-limiting toxicities were encountered. Comparison of cisplatin pharmacokinetics in patients treated with 202.5 mg/m2 plus thiosulfate to those in patients treated with 100 mg/m2 without thiosulfate indicated that there were no changes in the elimination rate constant, volume of distribution, or total body clearance of cisplatin. The total drug exposure for the plasma was approximately twofold at the higher cisplatin dose. This study demonstrates that concurrent administration of thiosulfate permits at least a twofold increase in dose and total exposure to cisplatin.

Hepatomesenteric release and removal of norepinephrine in swine

1995 ◽  
Vol 268 (4) ◽  
pp. R924-R930 ◽  
Author(s):  
A. Aneman ◽  
G. Eisenhofer ◽  
L. Fandriks ◽  
P. Friberg
Keyword(s):  
Total Body Clearance ◽  
Splanchnic Nerve ◽  
Neuronal Uptake ◽  
Blocking Drug ◽  
Hepatic Extraction ◽  
Valid Assessment ◽  
Total Body ◽  
Splanchnic Nerve Stimulation ◽  
Body Clearance ◽  
Venous Plasma

Release and removal of norepinephrine (NE) by hepatomesenteric organs in anesthetized swine were examined using measurements of NE in arterial, portal, and hepatic venous plasma. NE spillover from the liver and mesenteric organs increased during splanchnic nerve stimulation, validating these measurements as indexes of sympathetic outflow. Administration of the neuronal uptake-blocking drug desipramine reduced mesenteric NE extraction more than hepatic extraction, suggesting that neuronal uptake was more important for NE removal in mesenteric organs than in the liver. Circulating NE was removed by the liver more efficiently than by mesenteric organs, whereas mesenteric NE spillover (2.46 nmol/min) exceeded liver NE spillover (0.74 nmol/min). Hepatomesenteric NE spillover represented 53% of total body spillover; NE clearance was 42% of total body clearance. Because of efficient hepatic extraction of NE released by mesenteric organs, the sum of mesenteric and hepatic NE spillovers (3.20 pmol/min) exceeded net hepatomesenteric spillover estimated using arterial and hepatic venous measurements alone (1.96 pmol/min). Thus valid assessment of the substantial amounts of NE released by hepatomesenteric organs requires separate examination of mesenteric and hepatic spillovers.

scholarly journals β-Lactam Dosage Regimens in Septic Patients with Augmented Renal Clearance

2018 ◽  
Vol 62 (9) ◽  
Author(s):  
Alexandra Jacobs ◽  
Fabio Silvio Taccone ◽  
Jason A. Roberts ◽  
Frédérique Jacobs ◽  
Frederic Cotton ◽  
...  
Keyword(s):  
Creatinine Clearance ◽  
Renal Clearance ◽  
Total Body Clearance ◽  
Therapeutic Drug ◽  
Population Pharmacokinetic ◽  
Augmented Renal Clearance ◽  
Drug Concentrations ◽  
Trough Concentrations ◽  
Total Body ◽  
Body Clearance

ABSTRACTAugmented renal clearance is commonly observed in septic patients and may result in insufficient β-lactam serum concentrations. The aims of this study were to evaluate potential correlations between drug concentrations or total body clearance of β-lactam antibiotics and measured creatinine clearance and to quantify the need for drug dosage adjustments in septic patients with different levels of augmented renal clearance. We reviewed 256 antibiotic measurements (512 drug concentrations) from a cohort of 215 critically ill patients who had a measured creatinine clearance of ≥120 ml/min and who received therapeutic drug monitoring of meropenem, cefepime, ceftazidime, or piperacillin from October 2009 until December 2014 at Erasme Hospital. Population pharmacokinetic (PK) analysis of the data was performed using the Pmetrics software package for R. Fifty-five percent of drug concentrations showed insufficient β-lactam serum concentrations to treat infections due toPseudomonas aeruginosa. There were significant, yet weak, correlations between measured creatinine clearance and trough concentrations of meropenem (r= −0.21,P= 0.01), trough concentrations of piperacillin (r= −0.28,P= 0.0071), concentrations at 50% of the dosage interval (r= −0.41,P< 0.0001), and total body clearance of piperacillin (r= 0.39,P= 0.0002). Measured creatinine clearance adequately explained changes in drug concentrations in population pharmacokinetic models for cefepime, ceftazidime, and meropenem but not for piperacillin. Therefore, specific PK modeling can predict certain β-lactam concentrations based on renal function but not on absolute values of measured creatinine clearance, easily available for clinicians. Currently, routine therapeutic drug monitoring is required to adjust daily regimens in critically ill patients receiving standard dosing regimens.

Plasma concentration for optimal sedation and total body clearance of propofol in patients after esophagectomy

2005 ◽  
Vol 19 (1) ◽  
pp. 88-90 ◽  
Author(s):  
Daisuke Takizawa ◽  
Eri Sato ◽  
Koichi Nishikawa ◽  
Hiroshi Hinohara ◽  
Haruhiko Hiraoka ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Total Body Clearance ◽  
Total Body ◽  
Body Clearance

A toxicokinetic analysis in a patient with acute glufosinate poisoning

1999 ◽  
Vol 18 (5) ◽  
pp. 305-308 ◽  
Author(s):  
Y Hirose ◽  
M Kobayashi ◽  
K Koyama ◽  
Y Kohda ◽  
T Tanaka ◽  
...  
Keyword(s):  
Total Body Clearance ◽  
Artificial Ventilation ◽  
Compartment Model ◽  
Toxic Dose ◽  
Glufosinate Ammonium ◽  
Two Compartment Model ◽  
Serial Change ◽  
Total Body ◽  
Apparent Distribution ◽  
Body Clearance

Incidents of poisoning in humans caused by the ingestion of the glufosinate ammonium containing herbicides are gradually increasing in Japan. This poisoning is characterized by various neurological symptoms such as disturbances of consciousness, convulsions and apnea which appear after an asymptomatic interval of several hours. We studied the toxicokinetics of glufosinate in a patient with this poisoning successfully treated without extracorporeal hemopurification. A 65-year-old male ingested BASTA, which contains 20% w/v of glufosinate ammonium, about 300 ml, more than the estimated human toxic dose. Four and a half hours after ingestion, he showed speech ataxia and systemic tremor. He was prophylactically intubated before the occurrence of serious respiratory failure. After 5 days of artificial ventilation he was extubated and discharged without any sequelae. We studied the serial change of serum glufosinate concentration every 3-6 h and assessed the urinary excretion of glufosinate every 24 h. The absorbed amount of glufosinate was estimated from the cumulative excreted in urine. Toxicokinetic analysis was performed using the two-compartment model. The changes in serum glufosinate concentration exhibited T1/2α of 1.84 and T1/2α of 9.59 h. The apparent distribution volume at b-phase and the total body clearance were 1.44 l/kg and 86.6 ml/min, respectively. Renal clearance was estimated to be 77.9 ml/ min. The indication for extracorporeal hemopurification for this poisoning has been discussed.

Factors Influencing Procainamide Total Body Clearance in the Immediate Postmyocardial Infarction Period

1981 ◽  
Vol 21 (1) ◽  
pp. 20-25 ◽  
Author(s):  
MILFORD G. WYMAN ◽  
BRUCE N. GOLDREYER ◽  
DAVID S. CANNOM ◽  
THOMAS M. LUDDEN ◽  
DAVID LALKA
Keyword(s):  
Total Body Clearance ◽  
Postmyocardial Infarction ◽  
Factors Influencing ◽  
Total Body ◽  
Body Clearance
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