scholarly journals O35 Midazolam pharmacokinetics in children with obesity

2019 ◽  
Vol 104 (6) ◽  
pp. e15.2-e16
Author(s):  
C Gade ◽  
E Sverrisdóttir ◽  
K Dalhoff ◽  
J Sonne ◽  
H Rolighed Christensen ◽  
...  
Keyword(s):  
Body Weight ◽  
Status Epilepticus ◽  
Intravenous Administration ◽  
Plasma Concentrations ◽  
Total Body Weight ◽  
Volume Of Distribution ◽  
Convulsive Status Epilepticus ◽  
List Type ◽  
Obese Children ◽  
Total Body

BackgroundMidazolam is a first-line drug for treatment of status epilepticus,1 2 both by buccal and intravenous administration. In children with obesity, the midazolam pharmacokinetics may be altered, and the current dosing guidelines may therefore be insufficient.The aim of the study was to investigate the pharmacokinetics of midazolam, after intravenous administration, in obese and non-obese children, aged 11–18 years.MethodsTrial subjects were divided into groups by Body Mass Standard Deviation Score (SDS). All children received 1 µg midazolam administered an intravenous bolus dose. Thirteen blood samples were collected per participant at prespecified timepoints over 9 hours. Plasma concentration-time data was fitted to pharmacokinetic models using non-linear mixed effects modelling (NONMEM, 7.4).ResultsSeventy-two children were enrolled in the study, of these 67 children were included in the analysis. The pharmacokinetics of midazolam was best described with a two-compartment model. The changes in pharmacokinetics in children with obesity were best described with a linear function of BMI SDS on inter-compartmental clearance and peripheral volume. Thus, the rate of distribution was faster, and the peripheral volume of distribution was larger in children with obesity as compared to non-obese children. Simulations revealed that long-term infusions based on total body weight, could lead to high plasma concentrations in children with obesity. Furthermore, simulated plasma concentrations after a fixed buccal dose showed that children with obesity may be at risk of subtherapeutic plasma concentrations.ConclusionBMI SDS was shown to have a significant influence on the peripheral volume of distribution and the inter-compartmental clearance of midazolam. The current Danish dosing guidelines for status epilepticus (http://www.paediatri.dk), where midazolam dose is adjusted to total body weight or age, may lead to both supra- and subtherapeutic doses respectively, in children with obesity. However, confirmatory studies are needed.ReferencesSmith R, Brown J. Midazolam for status epilepticus. Aust Prescr. februar 2017;40(1):23–5.Ulvi H, Yoldas T, Müngen B, Yigiter R. Continuous infusion of midazolam in the treatment of refractory generalized convulsive status epilepticus. Neurol Sci Off J Ital Neurol Soc Ital Soc Clin Neurophysiol oktober 2002;23(4):177–82.Disclosure(s)Nothing to disclose

Pharmacokinetics and Drug Dosing in Obese Children

2010 ◽  
Vol 15 (2) ◽  
pp. 94-109
Author(s):  
Jennifer G. Kendrick ◽  
Roxane R. Carr ◽  
Mary H. H. Ensom
Keyword(s):  
Body Weight ◽  
Total Body Weight ◽  
Volume Of Distribution ◽  
Drug Dose ◽  
Normal Weight ◽  
Obese Children ◽  
Physiochemical Properties ◽  
Drug Dosing ◽  
Hydrophilic Drugs ◽  
Total Body

ABSTRACT OBJECTIVES To review pharmacokinetics in obese children and to provide medication dosing recommendations. METHODS EMBASE, MEDLINE, and International Pharmaceutical Abstracts databases were searched using the following terms: obesity, morbid obesity, overweight, pharmacokinetics, drug, dose, kidney function test, creatinine, pediatric, and child. RESULTS We identified 10 studies in which the authors examined drug dosing or pharmacokinetics for obese children. No information was found for drug absorption or metabolism. Obese children have a higher percent fat mass and a lower percent lean mass compared with normal-weight children. Therefore, in obese children, the volume of distribution of lipophilic drugs is most likely higher, and that of hydrophilic drugs is most likely lower, than in normal-weight children. Serum creatinine concentrations are higher in obese than normal-weight children. Total body weight is an appropriate size descriptor for calculating doses of antineoplastics, cefazolin, and succinylcholine in obese children. Initial tobramycin doses may be determined using an adjusted body weight, although using total body weight in the context of monitoring serum tobramycin concentrations would also be an appropriate strategy. We found no information for any of the opioids; antibiotics such as penicillins, carbapenems, vancomycin, and linezolid; antifungals; cardiac drugs such as digoxin and amiodarone; corticosteroids; benzodiazepines; and anticonvulsants. In particular, we found no information about medications that are widely distributed to adipose tissue or that can accumulate there. CONCLUSIONS The available data are limited because of the small numbers of participating children, study design, or both. The number and type of drugs that have been studied limit our understanding of the pharmacokinetics in obese children. In the absence of dosing information for obese children, it is important to consider the nature and severity of a child's illness, comorbidities, organ function, and side effects and physiochemical properties of the drug. Extrapolating from available adult data is possible, as long as practitioners consider the effects of growth and development on the pharmacokinetics relevant to the child's age.

Vancomycin volume of distribution estimation in adults with class III obesity

2019 ◽  
Author(s):  
Ryan D Dunn ◽  
Ryan L Crass ◽  
Joseph Hong ◽  
Manjunath P Pai ◽  
Lynne C Krop
Keyword(s):  
Body Weight ◽  
Total Body Weight ◽  
Volume Of Distribution ◽  
Patient Specific ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Parameter Estimates ◽  
Class Iii ◽  
Class Iii Obesity ◽  
Total Body

Abstract Purpose To compare methods of estimating vancomycin volume of distribution (V) in adults with class III obesity. Methods A retrospective, multicenter pharmacokinetic analysis of adults treated with vancomycin and monitored through measurement of peak and trough concentrations was performed. Individual pharmacokinetic parameter estimates were obtained via maximum a posteriori Bayesian analysis. The relationship between V and body weight was assessed using linear regression. Mean bias and root-mean-square error (RMSE) were calculated to assess the precision of multiple methods of estimating V. Results Of 241 patients included in the study sample, 159 (66.0%) had a BMI of 40.0–49.9 kg/m2, and 82 (34.0%) had a BMI of ≥50.0 kg/m2. The median (5th, 95th percentile) weight of patients was 136 (103, 204) kg, and baseline characteristics were similar between BMI groups. The mean ± S.D. V was lower in patients with a BMI of 40.0–49.9 kg/m2 than in those with a BMI of ≥50.0 kg/m2 (72.4 ± 19.6 L versus 79.3 ± 20.6 L, p = 0.009); however, body size poorly predicted V in regression analyses (R2 < 0.20). A fixed estimate of V (75 L) or use of 0.52 L/kg by total body weight yielded similar bias and error in this population. Conclusion Results of the largest analysis of vancomycin V in class III obesity to date indicated that use of a fixed V value (75 L) and use of a TBW-based estimate (0.52 L/kg) for estimation of vancomycin V in patients with a BMI of ≥40.0 kg/m2 have similar bias. Two postdistribution vancomycin concentrations are needed to accurately determine patient-specific pharmacokinetic parameters, estimate AUC, and improve the precision of vancomycin dosing in this patient population.

scholarly journals Pharmacokinetics of Ceftaroline in Normal Body Weight and Obese (Classes I, II, and III) Healthy Adult Subjects

2015 ◽  
Vol 59 (7) ◽  
pp. 3956-3965 ◽  
Author(s):  
Julie Ann Justo ◽  
Stockton M. Mayer ◽  
Manjunath P. Pai ◽  
Melinda M. Soriano ◽  
Larry H. Danziger ◽  
...  
Keyword(s):  
Body Weight ◽  
Healthy Adult ◽  
Plasma Concentrations ◽  
Area Under The Curve ◽  
Total Body Weight ◽  
Pharmacokinetic Profile ◽  
Volume Of Distribution ◽  
Population Pharmacokinetic ◽  
Ceftaroline Fosamil ◽  
Plasma And Urine Samples

ABSTRACTThe pharmacokinetic profile of ceftaroline has not been well characterized in obese adults. The purpose of this study was to evaluate the pharmacokinetics of ceftaroline in 32 healthy adult volunteers aged 18 to 50 years in the normal, overweight, and obese body size ranges. Subjects were evenly assigned to 1 of 4 groups based on their body mass index (BMI) and total body weight (TBW) (ranges, 22.1 to 63.5 kg/m2and 50.1 to 179.5 kg, respectively). Subjects in the lower-TBW groups were matched by age, sex, race/ethnicity, and serum creatinine to the upper-BMI groups. Serial plasma and urine samples were collected over 12 h after the start of the infusion, and the concentrations of ceftaroline fosamil (prodrug), ceftaroline, and ceftaroline M-1 (inactive metabolite) were assayed. Noncompartmental and population pharmacokinetic analyses were used to evaluate the data. The mean plasma ceftaroline maximum concentration and area under the curve were ca. 30% lower in subjects with a BMI of ≥40 kg/m2compared to those <30 kg/m2. A five-compartment pharmacokinetic model with zero-order infusion and first-order elimination optimally described the plasma concentration-time profiles of the prodrug and ceftaroline. Estimated creatinine clearance (eCLCR) and TBW best explained ceftaroline clearance and volume of distribution, respectively. Although lower ceftaroline plasma concentrations were observed in obese subjects, Monte Carlo simulations suggest the probability of target attainment is ≥90% when the MIC is ≤1 μg/ml irrespective of TBW or eCLCR. No dosage adjustment for ceftaroline appears to be necessary based on TBW alone in adults with comparable eCLCR. Confirmation of these findings in infected obese patients is necessary to validate these findings in healthy volunteers. (This study has been registered at ClinicalTrials.gov under registration no. NCT01648127.)

scholarly journals Pharmacokinetics of Clindamycin in Obese and Nonobese Children

2017 ◽  
Vol 61 (4) ◽  
Author(s):  
Michael J. Smith ◽  
Daniel Gonzalez ◽  
Jennifer L. Goldman ◽  
Ram Yogev ◽  
Janice E. Sullivan ◽  
...  
Keyword(s):  
Total Body Weight ◽  
The United States ◽  
Volume Of Distribution ◽  
Model Parameters ◽  
Obese Children ◽  
Obesity Status ◽  
Postmenstrual Age ◽  
Total Body ◽  
Using Data ◽  
Require Dose

ABSTRACT Although obesity is prevalent among children in the United States, pharmacokinetic (PK) data for obese children are limited. Clindamycin is a commonly used antibiotic that may require dose adjustment in obese children due to its lipophilic properties. We performed a clindamycin population PK analysis using data from three separate trials. A total of 420 samples from 220 children, 76 of whom had a body mass index greater than or equal to the 95th percentile for age, were included in the analysis. Compared to other metrics, total body weight (TBW) was the most robust measure of body size. The final model included TBW and a sigmoidal maturation relationship between postmenstrual age (PMA) and clearance (CL): CL (liters/hour) = 13.8 × (TBW/70)0.75 × [PMA2.83/(39.52.83+PMA2.83)]; volume of distribution (V) was associated with TBW, albumin (ALB), and alpha-1 acid glycoprotein (AAG): V (liters) = 63.6 × (TBW/70) × (ALB/3.3)−0.83 × (AAG/2.4)−0.25. After accounting for differences in TBW, obesity status did not explain additional interindividual variability in model parameters. Our findings support TBW-based dosing for obese and nonobese children.

scholarly journals Pharmacokinetics of Telavancin in Adult Patients with Cystic Fibrosis during Acute Pulmonary Exacerbation

2019 ◽  
Vol 64 (1) ◽  
Author(s):  
James M. Kidd ◽  
Colleen M. Sakon ◽  
Louise-Marie Oleksiuk ◽  
Jeffrey J. Cies ◽  
Rebecca S. Pettit ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Body Weight ◽  
Total Body Weight ◽  
Central Compartment ◽  
Volume Of Distribution ◽  
Peripheral Compartment ◽  
Population Pharmacokinetic ◽  
Minimal Risk ◽  
Content Type ◽  
Total Body

ABSTRACT Adults with cystic fibrosis (CF) frequently harbor Staphylococcus aureus, which is increasingly antibiotic resistant. Telavancin is a once-daily rapidly bactericidal antibiotic active against methicillin-, linezolid-, and ceftaroline-resistant S. aureus. Because CF patients experience alterations in pharmacokinetics, the optimal dose of telavancin in this population is unknown. Adult CF patients (n = 18) admitted for exacerbations received 3 doses of telavancin 7.5 mg/kg of body weight (first 6 patients) or 10 mg/kg (final 12 patients) every 24 h (q24h). Population pharmacokinetic models with and without covariates were fitted using the nonparametric adaptive grid algorithm in Pmetrics. The final model was used to perform 5,000-patient Monte Carlo simulations for multiple telavancin doses. The best fit was a 2-compartment model describing the volume of distribution of the central compartment (Vc) as a multiple of total body weight (TBW) and the volume of distribution of the central compartment scaled to total body weight (Vθ) normalized by the median observed value (Vc = Vθ × TBW/52.1) and total body clearance (CL) as a linear function of creatinine clearance (CRCL) (CL = CLNR + CLθ × CRCL), where CLNR represents nonrenal clearance and CLθ represents the slope term on CRCL to estimate renal clearance. The mean population parameters were as follows: Vθ, 4.92  ± 0.76 liters · kg−1; CLNR, 0.59  ± 0.30 liters · h−1; CLθ, 5.97 × 10−3 ± 1.24 × 10−3; Vp (volume of the peripheral compartment), 3.77  ± 1.41 liters; Q (intercompartmental clearance), 4.08  ± 2.17 liters · h−1. The free area under the concentration-time curve (fAUC) values for 7.5 and 10 mg/kg were 30  ± 4.6 and 52  ± 12 mg · h/liter, respectively. Doses of 7.5 mg/kg and 10 mg/kg achieved 76.5% and 100% probability of target attainment (PTA) at a fAUC/MIC threshold of >215, respectively, for MIC of ≤0.12 mg/liter. The probabilities of reaching the acute kidney injury (AKI) threshold AUC (763 mg · h · liter−1) for these doses were 0% and 0.96%, respectively. No serious adverse events occurred. Telavancin 10 mg/kg yielded optimal PTA and minimal risk of AKI, suggesting that this FDA-approved dose is appropriate to treat acute pulmonary exacerbations in CF adults. (The clinical trial discussed in this study has been registered at ClinicalTrials.gov under identifier NCT03172793.)

scholarly journals A Large Impact of Obesity on the Disposition of Ivermectin, Moxidectin and Eprinomectin in a Canine Model: Relevance for COVID-19 Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Alain Bousquet-Mélou ◽  
Anne Lespine ◽  
Jean-François Sutra ◽  
Isabelle Bargues ◽  
Pierre-Louis Toutain
Keyword(s):  
Body Weight ◽  
Steady State ◽  
Obese Subject ◽  
Control Period ◽  
Total Body Weight ◽  
Canine Model ◽  
Volume Of Distribution ◽  
Lean Body Weight ◽  
Total Body

Ivermectin (IVM) and moxidectin (MOX) are used extensively as parasiticides in veterinary medicine. Based on in vitro data, IVM has recently been proposed for the prevention and treatment of COVID-19 infection, a condition for which obesity is a major risk factor. In patients, IVM dosage is based on total body weight and there are no recommendations to adjust dosage in obese patients. The objective of this study was to establish, in a canine model, the influence of obesity on the clearance and steady-state volume of distribution of IVM, MOX, and a third analog, eprinomectin (EPR). An experimental model of obesity in dogs was based on a high calorie diet. IVM, MOX, and EPR were administered intravenously, in combination, to a single group of dogs in two circumstances, during a control period and when body weight had been increased by 50%. In obese dogs, clearance, expressed in absolute values (L/day), was not modified for MOX but was reduced for IVM and EPR, compared to the initial control state. However, when scaled by body weight (L/day/kg), plasma clearance was reduced by 55, 42, and 63%, for IVM, MOX and EPR, respectively. In contrast, the steady-state volume of distribution was markedly increased, in absolute values (L), by obesity. For IVM and MOX, this obese dog model suggests that the maintenance doses in the obese subject should be based on lean body weight rather than total weight. On the other hand, the loading dose, when required, should be based on the total body weight of the obese subject.

scholarly journals Pharmacokinetics of Intravenous Linezolid in Moderately to Morbidly Obese Adults

2012 ◽  
Vol 57 (3) ◽  
pp. 1144-1149 ◽  
Author(s):  
Amira A. Bhalodi ◽  
Pavlos K. Papasavas ◽  
Darren S. Tishler ◽  
David P. Nicolau ◽  
Joseph L. Kuti
Keyword(s):  
Body Weight ◽  
Ideal Body Weight ◽  
Total Body Weight ◽  
Compartment Model ◽  
Central Compartment ◽  
Volume Of Distribution ◽  
Lean Body Weight ◽  
Morbidly Obese ◽  
Total Body ◽  
Nonobese Patients

ABSTRACTThe pharmacokinetics of linezolid was assessed in 20 adult volunteers with body mass indices (BMI) of 30 to 54.9 kg/m2receiving 5 intravenous doses of 600 mg every 12 h. Pharmacokinetic analyses were conducted using compartmental and noncompartmental methods. The mean (±standard deviation) age, height, and weight were 42.2 ± 12.2 years, 64.8 ± 3.5 in, and 109.5 ± 18.2 kg (range, 78.2 to 143.1 kg), respectively. Linezolid pharmacokinetics in this population were best described by a 2-compartment model with nonlinear clearance (original value, 7.6 ± 1.9 liters/h), which could be inhibited to 85.5% ± 12.2% of its original value depending on the concentration in an empirical inhibition compartment, the volume of the central compartment (24.4 ± 9.6 liters), and the intercompartment transfer constants (K12andK21) of 8.04 ± 6.22 and 7.99 ± 5.46 h−1, respectively. The areas under the curve for the 12-h dosing interval (AUCτ) were similar between moderately obese and morbidly obese groups: 130.3 ± 60.1 versus 109.2 ± 25.5 μg · h/ml (P= 0.32), and there was no significant relationship between the AUC or clearance and any body size descriptors. A significant positive relationship was observed for the total volume of distribution with total body weight (r2= 0.524), adjusted body weight (r2= 0.587), lean body weight (r2= 0.495), and ideal body weight (r2= 0.398), but not with BMI (r2= 0.171). Linezolid exposure in these obese participants was similar overall to that of nonobese patients, implying that dosage adjustments based on BMI alone are not required, and standard doses for patients with body weights up to approximately 150 kg should provide AUCτ values similar to those seen in nonobese participants.

scholarly journals Large Impact of obesity on the disposition of ivermectin, moxidectin and eprinomectin in a canine model: relevance for COVID-19 patients.

2021 ◽  
Author(s):  
Alain Bousquet-Melou ◽  
Anne Lespine ◽  
Jean-François Sutra ◽  
Isabelle Bargues ◽  
Pierre Louis Toutain
Keyword(s):  
Body Weight ◽  
Steady State ◽  
Obese Subject ◽  
Control Period ◽  
Total Body Weight ◽  
Canine Model ◽  
Volume Of Distribution ◽  
Lean Body Weight ◽  
Total Body

Background and Purpose: Based on in vitro data, ivermectin (IVM) has been proposed for the prevention and treatment of COVID-19, a condition for which obesity is a major risk factor. IVM dosage is based on total body weight and there are no recommendations to adjust dosage in obese patients. The objective of this study was to establish, in a canine model, the influence of obesity on the clearance and steady-state volume of distribution of IVM and two analog compounds, moxidectin (MOX) and eprinomectin (EPR). Experimental Approach: An experimental model of obesity in dogs was based on a high calorie diet. IVM, MOX and EPR were administered intravenously, simultaneously in combination, to a single group of dogs in two circumstances, during a control period and when body weight had been increased by 50%. Key Results: In obese dogs, clearance, expressed in absolute values (L/day), was not modified for MOX and reduced for IVM and EPR, compared to the initial control state. When scaled by body weight (L/day/kg), plasma clearance was reduced by 42, 55 and 63%, for MOX, IVM and EPR, respectively. In contrast, the steady-state volume of distribution was markedly increased in absolute values (L) by obesity. Conclusion and Implications: For IVM and MOX, the obese dog model suggests that the maintenance dose should not be adjusted by total body weight in the obese subject but should be based on lean body weight. On the other hand, the loading dose should be computed based on the total body weight of the obese subject.

Prescribing in obese children: how good are paediatricians?

2016 ◽  
Vol 102 (1) ◽  
pp. 61-62 ◽  
Author(s):  
Helen Collier ◽  
Maria Nasim ◽  
Anjum Gandhi
Keyword(s):  
Body Weight ◽  
Childhood Obesity ◽  
Ideal Body Weight ◽  
Total Body Weight ◽  
Obese Children ◽  
Poor Understanding ◽  
Drug Doses ◽  
Ideal Body ◽  
Total Body ◽  
The Ideal

Childhood obesity is increasing nationally and worldwide. Using the child's total body weight to calculate drug doses for certain medications could result in incorrect dosing. The aim of this study was to assess whether paediatric doctors have knowledge about prescribing correct doses of medications for obese children by using methods to calculate the ‘ideal body weight’ (IBW). A questionnaire was sent to paediatric doctors asking whether they understand IBW and how to calculate it using the McLaren method. The results suggested that most paediatric doctors did not determine whether a child was obese when calculating drug doses. There was relatively poor understanding about the concept of IBW and only 9% of paediatricians in this study knew how to calculate it. There should be more training and guidance about calculating IBW in obese children to avoid potentially toxic errors.

scholarly journals Lean body weight versus total body weight to calculate the iodinated contrast media volume in abdominal CT: a randomised controlled trial

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Moreno Zanardo ◽  
Fabio Martino Doniselli ◽  
Anastassia Esseridou ◽  
Massimiliano Agrò ◽  
Nicol Antonina Rita Panarisi ◽  
...  
Keyword(s):  
Body Weight ◽  
Contrast Media ◽  
Controlled Trial ◽  
Total Body Weight ◽  
Lean Body Weight ◽  
Iodinated Contrast Media ◽  
Abdominal Ct ◽  
Iodinated Contrast ◽  
Significant Difference ◽  
Total Body

Abstract Objectives Iodinated contrast media (ICM) could be more appropriately dosed on patient lean body weight (LBW) than on total body weight (TBW). Methods After Ethics Committee approval, trial registration NCT03384979, patients aged ≥ 18 years scheduled for multiphasic abdominal CT were randomised for ICM dose to LBW group (0.63 gI/kg of LBW) or TBW group (0.44 gI/kg of TBW). Abdominal 64-row CT was performed using 120 kVp, 100–200 mAs, rotation time 0.5 s, pitch 1, Iopamidol (370 mgI/mL), and flow rate 3 mL/s. Levene, Mann–Whitney U, and χ2 tests were used. The primary endpoint was liver contrast enhancement (LCE). Results Of 335 enrolled patients, 17 were screening failures; 44 dropped out after randomisation; 274 patients were analysed (133 LBW group, 141 TBW group). The median age of LBW group (66 years) was slightly lower than that of TBW group (70 years). Although the median ICM-injected volume was comparable between groups, its variability was larger in the former (interquartile range 27 mL versus 21 mL, p = 0.01). The same was for unenhanced liver density (IQR 10 versus 7 HU) (p = 0.02). Median LCE was 40 (35–46) HU in the LBW group and 40 (35–44) HU in the TBW group, without significant difference for median (p = 0.41) and variability (p = 0.23). Suboptimal LCE (< 40 HU) was found in 64/133 (48%) patients in the LBW group and 69/141 (49%) in the TBW group, but no examination needed repeating. Conclusions The calculation of the ICM volume to be administered for abdominal CT based on the LBW does not imply a more consistent LCE.

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