scholarly journals An Evaluation of Systemic Vancomycin Dosing in Obese Patients

2015 ◽  
Vol 2 (4) ◽  
Author(s):  
David W. Kubiak ◽  
Mohammed Alquwaizani ◽  
David Sansonetti ◽  
Megan E. Barra ◽  
Michael S. Calderwood

Abstract We retrospectively identified 67 patients with severe or morbid obesity (body mass index ≥35 kg/m2) who had received intravenous vancomycin at our institution. We observed that an initial dose of 45 to 65 mg/kg vancomycin per day based upon ideal body weight rather than actual body weight was more predictive of initial trough concentrations between 15 and 20 mcg/mL.

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4535-4535
Author(s):  
Noga Shem-Tov ◽  
Myriam Labopin ◽  
Leila Moukhtari ◽  
Fabio Ciceri ◽  
Jordi Esteve ◽  
...  

Rates of obesity have substantially increased in recent years. Pharmacokinetics of drugs including chemotherapy is different in obese patients due to alteration in the clearance and volume of distribution. Thus, appropriate chemotherapy dosing for obese patients with malignant diseases is a significant issue. Limiting chemotherapy doses in overweight and obese patients may negatively influence the outcomes in these patients. ASCO has recently published clinical practice guidelines for conventional chemotherapy dosing for obese patients with cancer indicating that up to 40% of obese patients received reduced chemotherapy doses that are not based on actual body weight (ABW) [Grigg A, JCO 2012]. Concerns about toxicity or overdosing in obese patients, based on the use of ABW, are unfounded. Moreover, there is a paucity of information addressing the pharmacokinetics of high dose chemotherapy in obese patients undergoing hematopoietic stem cell transplantation (HSCT). A rather small international survey of drug dosing schemes among transplant centers revealed that there is no consensus regarding appropriate dose adjustment for obese patients [Grigg A, Leuk Lymphoma 1997]. Also, there is limited data on outcomes in obese versus non-obese patients in various small retrospective studies. For this reason, the ALWP of the EBMT constructed an electronic survey for assessing current practice of dose adjustment of chemotherapy in patients undergoing HSCT, in transplant centers and for planning retrospective analysis and prospective studies in the future. Fifty six EBMT centers from 27 countries filled the online survey. Among the 56 centers, the percentage of obese patients was less than 10% in 22 centers (40%), between 10 to 19% in 23 centers (42%) and more than 20% in 10 centers (17%). Forty five centers declared they adjust chemotherapy dose for obese patients (80.5%) and only 11 (19.5%) declared they do not adjust dose. Among centers which adjust dose, most uses BMI as the parameter for defining obesity (28 centers, 62%), others use percentage over the actual body weight (ABW) as the basis for defining obesity (11 centers, 24.5%), both BMI and ABW (3 centers, 6.7%) or other parameter (3 centers, 6.7%). Most of the centers that use BMI for adjusting dose define BMI > 30 kg/m2 as the cut-off value (formal definition for obesity), only one center uses morbid obesity (BMI > 40 kg/m2), and the remainder uses other cut-off values. Among 11 centers who use ABW, 9 use ABW more than 120% of ideal body weight for adjustment. Eighty four percents of the centers use one level of obesity for adjustment while the rest uses 2 levels. The method for determining the weight for chemotherapy calculation was actual body weight (ABW) in 16 centers, ideal body weight (IBW) in 10 centers, IBW + 25% of difference between IBW and ABW (IBW+0.25*(ABW-IBW)) in 16 centers and other methods in the rest. Among centers that use dose adjustment, 44% also cap the dose at 2 m2 for chemotherapy dose based on BSA while 56% do not cap. On the contrary, most of the centers (9/11) that do not adjust dose for weight also do not cap the BSA at 2 m2. Seventy nine percents of responding centers use the same approach to dose adjustments for myeloablative, reduced intensity (RIC) or non myeloablative (NMA) conditioning, while 21% reduce the dose less for RIC or NMA conditioning. For Busulfan dose only 7 centers monitor pharmacokinetics (pk). Eleven centers use ideal body weight for calculation, 17 centers use actual weight and 18 centers correct weight according to percentage over actual body weight. Conclusion This EBMT survey reveal large diversity among transplant centers regarding dose adjustment practice for high dose conditioning chemotherapy. Most of the EBMT centers use dose adjustment for obese patients and about half of them also cap BSA at 2 m2, while capping is uncommon in the centers that do not adjust dose. Thus, the range of the final dose is very wide. Even for Busulfan where dose is calculated normally according to ideal body weight, the diversity of dose given for obese patients is wide. Our next step is to analyze outcomes of transplantation according to dose adjustment practice and subsequently to formulate a methodology for future prospective studies. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5445-5445
Author(s):  
Lijo Simpson ◽  
Robert C. Wolfe ◽  
Dennis A. Gastineau ◽  
William J. Hogan ◽  
Shaji Kumar

Abstract Background: Obesity is a prevalent health problem and significant heterogeneity is seen in the body weight and BMI among adult patients undergoing autologous stem cell transplantation (SCT). At least two critical steps of the SCT are influenced by the body weight. Stem cell collection targets are usually determined based on the actual body weight and conditioning chemotherapy doses are usually determined based on corrected ideal body weight. One could hypothesize that since the stem cells home to bone marrow, the ideal body weight (IBW) being based on the height may be a better indicator of the stem cell numbers required rather than the actual body weight (ABW). Since chemotherapy doses are calculated based on corrected ideal body weight, and the volume of distribution is higher in obese patients, these patients may have decreased drug exposure and hence a higher risk of progression. Methods: We retrospectively evaluated the engraftment kinetics and response outcome of 306 SCTs done at our institution between March 1998 and October 2001. These included patients who had undergone SCT for multiple myeloma (46%), NHL (34%), HD (6%) and AL amyloidosis (14%). Body weight, height, stem cell dose and engraftment data was obtained from medical records. The stem cell dose received was calculated based on their ABW as well as IBW and correlated with the time to white cell and platelet engraftment. We also evaluated the effect of BMI on the progression free survival after the stem cell transplant using various cut offs. Results: The mean (range) for the ABW, IBW and BMI were 46.6 kg to 189 Kg; 45.5 kg to 94 kg; and 17.5 to 55.8 respectively. Using logistic regression, we estimated the ability of CD34 cell dose by actual and ideal body weight to predict the likelihood of platelet engraftment (50,000) by day 21 post transplant. The coefficients using both the doses were very similar (.391 for ideal and 0.361 for actual). Using Receiver operating characteristic analysis (ROC analysis); we determined the stem cell dose cutoff that best predicted for failure to engraft neutrophils by 21 days post transplantation, median CD34 dose by ABW of 3.6 million/Kg and by IBW of 4.2 million/Kg. Similarly, for failure to engraft platelets by day 30 the cutoffs were 2.89 million/Kg by actual weight and 3.77 million/kg by ideal weight. Among the individuals with actual body weight more than 25% of ideal body weight (n=122, 40%), we calculated the optimal total CD34 dose required and compared to the actual dose infused using both the cutoff sets (286 million vs. 446 million, P < 0.001 using ANC cutoff and 251 million vs. 446 million using the platelet cutoff, P < 0.001). We then examined the effect of BMI on progression free and overall survival from transplant. The progression free and overall survival post transplant was similar for patients with BMI over 30 kg/m2 compared to those below this cutoff. There was no difference when patients with myeloma or lymphoma were studied separately. Conclusion: This study, as in previous studies, confirms that stem cell dose determined on the basis of ideal body weight is comparable to that by actual body weight in terms of engraftment kinetics. In patients significantly above the ideal body weight, it is reasonable to use a target based on ideal body weight which will allow for collection of less numbers of CD34 cells, thus conserving resources. Among patient undergoing stem cell transplant, the practice of using corrected ideal body weight does not appear to compromise the outcome of stem cell transplant.


2013 ◽  
Vol 58 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Jennifer K. Ng ◽  
Lucas T Schulz ◽  
Warren E. Rose ◽  
Barry C. Fox ◽  
David R. Andes ◽  
...  

ABSTRACTDaptomycin use at our institution changed to ideal body weight dosing based on a published analysis of pharmacokinetic-pharmacodynamic efficacy target attainment, bacterial ecology, and a desire to reduce drug toxicity. The current study compared outcomes between actual body weight and ideal body weight dosing of daptomycin before and after this intervention. In the evaluable group, 69 patients received doses based on actual body weight and 48 patients received doses based on ideal body weight. Patients were treated for documentedEnterococcusspecies,Staphylococcus aureus, or coagulase-negativeStaphylococcusinfections, including bloodstream, intraabdominal, skin and soft tissue, urinary, and bone. There was no statistically significant difference in clinical success between the groups (88.9% for actual body weight compared to 89.1% for ideal body weight,P= 0.97). After we adjusted for gender, age, body mass index, concomitant 3-hydroxy-3-methylglutaryl–coenzyme A reductase inhibitors, infection type, and organism type, clinical success rates remained similar between groups (adjusted odds ratio of 0.68 in favor of actual body weight, 95% confidence interval [CI] of 0.13 to 3.55). Microbiological outcomes, length of stay, mortality, and adverse effects were also similar between groups. Further studies are warranted to confirm that ideal body weight dosing provides similar outcomes to actual body weight dosing for all patients and types of infections and organisms.


2008 ◽  
Vol 18 (2) ◽  
pp. 345-351 ◽  
Author(s):  
I. Skírnisdóttir ◽  
B. Sorbe

The present study was performed to find out if the body mass index (BMI) was associated with clinical and pathologic features (age, histology, tumor grade, and substages) and prognosis in early stages (FIGO I–II) of epithelial ovarian cancer. Further aims of the study were to evaluate if overweight or obesity affected the feasibility of optimal surgery and postoperative adjuvant therapy. A total of 635 patients were included in this study. Four percent of the patients were underweight (BMI <18.5), 53% were of ideal body weight (BMI 18.5–25), 31% were overweight (BMI 25–30), and 12% were obese (BMI >30). Overweight and obese patients were significantly (P= 0.006) older than underweight and ideal body weight patients. Tumor grade and histologic type distributions were not different across the BMI strata. FIGO stage (P= 0.011) and presence of ascites (P= 0.007) at primary surgery were associated with the BMI status. A history of cardiovascular disease was significantly (P= 0.006) more common in overweight and obese patients. Survival analyses in the four BMI subgroups did not show any significant differences with regard to recurrence-free survival. The 5-year recurrence-free survival of the complete series was 72%. Overweight and obese patients did not have worse survival than normal weight and underweight patients. Perioperative or postoperative morbidity and adjuvant oncologic treatment were not affected by the BMI. In a multivariate Cox analysis, FIGO substage and tumor grade, but not BMI, were independent and significant prognostic factors with regard to all types of survival rates.


2007 ◽  
Vol 25 (30) ◽  
pp. 4707-4713 ◽  
Author(s):  
Alex Sparreboom ◽  
Antonio C. Wolff ◽  
Ron H.J. Mathijssen ◽  
Etienne Chatelut ◽  
Eric K. Rowinsky ◽  
...  

Purpose Despite the rising prevalence of obesity, there is paucity of information describing how doses of anticancer drugs should be adjusted in clinical practice. Here, we assessed the pharmacokinetics of eight anticancer drugs in adults and evaluated the potential utility of alternative weight descriptors in dose calculation for the obese. Patients and Methods A total of 1,206 adult cancer patients were studied, of whom 162 (13.4%) were obese (body mass index ≥ 30). Pharmacokinetic parameters were calculated using noncompartmental analysis, and compared between lean (body mass index ≤ 25) and obese patients. Results The absolute clearance of cisplatin, paclitaxel, and troxacitabine was significantly increased in the obese (P < .023), but this was not observed for carboplatin, docetaxel, irinotecan, or topotecan (P < .17). For doxorubicin, the systemic clearance was statistically significantly reduced in obese women (P = .013), but not in obese men (P = .52). Evaluation of alternate weight descriptors for dose calculation in the obese, including predicted normal weight, lean body mass, (adjusted) ideal body weight, and the mean of ideal and actual body weight, indicated that, for most of the evaluated drugs, weight scalars used to calculate body-surface area should consider actual body weight regardless of size. Conclusion The results suggest that a number of widely used empiric strategies for dose adjustments in obese patients, including a priori dose reduction or dose capping, should be discouraged.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
H. Reza Ahmadian ◽  
Joseph J. Sclafani ◽  
Ethan E. Emmons ◽  
Michael J. Morris ◽  
Kenneth M. Leclerc ◽  
...  

Background. Oxygen uptake at maximal exercise (VO2max) is considered the best available index for assessment of exercise capacity. The purpose of this study is to determine if the use of actual versus ideal body weight in standard regression equations for predicted VO2max results in differences in predicted VO2max.Methods. This is a retrospective chart review of patients who were predominantly in active military duty with complaints of dyspnea or exercise tolerance and who underwent cardiopulmonary exercise testing (CPET) from 2007 to 2009.Results. A total of 230 subjects completed CPET on a bicycle ergometer with a male predominance (62%) and an average age of 37 ± 15 years. There was significant discordance between the measured VO2max and predicted VO2max when measured by the Hansen and Wasserman reference equations (P<0.001). Specifically, there was less overestimation when predicted VO2max was based on ideal body weight as opposed to actual body weight.Conclusion. Our retrospective analysis confirmed the wide variations in predicted versus measured VO2max based on varying prediction equations and showed the potential advantage of using ideal body weight as opposed to actual body weight in order to further standardize reference norms.


2021 ◽  
pp. 152692482110032
Author(s):  
Rachel J. Bubik ◽  
Kristen T. Peterson ◽  
Laura J. Myhre ◽  
Stacy A. Bernard ◽  
Patrick Dean ◽  
...  

Introduction: Contemporary dosing strategies for rabbit anti-thymocyte globulin (rATG) in kidney transplantation aim to reduce cumulative exposure, minimizing long-term adverse events. The use of ideal body weight-based dosing has been trialed, however concern for increased rejection post-transplant exists due to lower doses of rATG. Research Questions: The primary aim of this study was to compare rejection rates between rATG dosing protocols using actual body weight and ideal body weight and secondarily to evaluate cost savings following protocol implementation. Design: This was a retrospective study surrounding implementation of an ideal body weight-based dosing protocol for rATG. We compared 75 kidney transplant recipients in whom rATG was dosed based on actual body weight (pre-protocol group) to 64 in whom dosing was based on ideal body weight (post-protocol group), following a nine-month washout. Results: The mean cumulative rATG dose in the pre-protocol group was 6.3 mg/kg of actual body weight. When ideal body weight was used in the post-protocol group, the mean dose was 4.5 mg/kg of actual body weight. The rejection rate was 18.7% pre-protocol and 23.4% postprotocol, which did not represent a statistically significant difference (p = 0.491). The actual annual cost savings after protocol implementation exceeded $162,000, approximately $2,500 per patient. Conclusion: Results suggest ideal body weight-based dosing of rATG may reduce exposure and cost, without significantly impacting the risk of rejection in kidney transplant recipients. More studies are needed to confirm these findings.


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