1
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Guan JL, Han YY, Wang MR, Xia SH, Li JY, Zhang MY, Zhao K, Feng LN, Zhang Y, Dong RN, Liao JZ, Li PY. Impact of body size on efficacy of high-dose dual therapy for Helicobacter pylori eradication. Helicobacter 2023; 28:e12953. [PMID: 36738099 DOI: 10.1111/hel.12953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 01/11/2023] [Accepted: 01/15/2023] [Indexed: 02/05/2023]
Abstract
BACKGROUND High-dose dual therapy (HDDT) is an emerging and promising therapeutic regime for Helicobacter pylori (H. pylori) eradication. However, the pharmacokinetics of the components of HDDT, amoxicillin and proton pump inhibitor, are likely to be affected by body size. In this study, we aimed to find out the impact of body size on the efficacy of HDDT. METHODS We collected the medical data of 385 treatment-naive patients infected with H. pylori who received HDDT (esomeprazole 20 mg and amoxicillin 750 mg four times daily) for 14 days from July 2020 to December 2021. The associations among the eradication efficacy, adverse events, and variables (sex, age, height, body weight, body mass index (BMI), body surface area (BSA), smoking, drinking, etc.) were analyzed respectively in our study. Among these factors, continuous variables were classified into categorical variables using the cut-off values which were calculated by receiver operating characteristic analysis. RESULTS The eradication rate of HDDT was 89.9%. There were 55 (14.3%) patients who occurred adverse events during the treatment. Patients with height <170.5 cm, body weight <60.5 kg, BMI <20.55 kg/m2 , BSA <1.69 m2 had a higher eradication rate (92.1% vs. 84.0%, 93.1% vs. 86.8%, 96.0% vs. 87.8%, 93.4% vs. 84.8%, all p < .05). The multivariate analysis showed that BSA ≥1.69 m2 (OR 2.53, 95% CI: 1.28-4.99, p = .007) was the only independent predictor of eradication failure. CONCLUSION HDDT could achieve better eradication efficacy in patients with small BSA. Clinicians should be aware of the impact of BSA on the H. pylori eradication rate and pay more attention to patients with large BSA.
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Affiliation(s)
- Jia-Lun Guan
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying-Ying Han
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Mu-Ru Wang
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Su-Hong Xia
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ji-Yan Li
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ming-Yu Zhang
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kai Zhao
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li-Na Feng
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Zhang
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ruo-Nan Dong
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jia-Zhi Liao
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Pei-Yuan Li
- Division of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Gastroenterology, Wenchang People's Hospital, Wenchang, China
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Mieresova M, Balazova K, Kubele J, Cerny D, Halacova M. Piperacillin/Tazobactam in critically ill morbidly obese patients: A case series: The first One-Centre experience with TDM. Clin Case Rep 2023; 11:e7032. [PMID: 36919150 PMCID: PMC10008261 DOI: 10.1002/ccr3.7032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 01/20/2023] [Accepted: 02/13/2023] [Indexed: 03/14/2023] Open
Abstract
The aim of this article is to demonstrate extreme interindividual variability of piperacilin/tazobactam (PIP/TAZO) pharmacokinetics in critically ill morbidly obese patients and to emphasize the need for the practice of routine PIP/TAZO plasma concentrations measurement in order to ensure optimal efficacy and safety of antibiotic therapy.
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Affiliation(s)
- M Mieresova
- Department of Clinical Pharmacy Na Homolce Hospital Prague Czech Republic.,Department of Pharmacology Motol University Hospital and 2nd Faculty of Medicine, Charles University Prague Czech Republic
| | - K Balazova
- Department of Clinical Pharmacy Na Homolce Hospital Prague Czech Republic
| | - J Kubele
- Department of Clinical Microbiology and Antibiotic Surveillance Na Homolce Hospital Prague Czech Republic
| | - D Cerny
- Department of Clinical Pharmacy Na Homolce Hospital Prague Czech Republic.,Institute of Pharmacology, General University Hospital and 1st Faculty of Medicine, Charles University Prague Czech Republic
| | - M Halacova
- Department of Clinical Pharmacy Na Homolce Hospital Prague Czech Republic.,Department of Pharmacology Motol University Hospital and 2nd Faculty of Medicine, Charles University Prague Czech Republic
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3
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Mellon G, Hammas K, Burdet C, Duval X, Carette C, El-Helali N, Massias L, Mentré F, Czernichow S, Crémieux AC. Population pharmacokinetics and dosing simulations of amoxicillin in obese adults receiving co-amoxiclav. J Antimicrob Chemother 2021; 75:3611-3618. [PMID: 32888018 DOI: 10.1093/jac/dkaa368] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/27/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Pneumonia, skin and soft tissue infections are more frequent in obese patients and are most often treated by co-amoxiclav, using similar dosing regimens to those used for non-obese subjects. No data are available on amoxicillin pharmacokinetics among obese subjects receiving co-amoxiclav. MATERIALS AND METHODS Prospective, single-centre, open-label, non-randomized, crossover pharmacokinetic trial having enrolled obese otherwise healthy adult subjects. A first dose of co-amoxiclav (amoxicillin/clavulanate 1000/200 mg) was infused IV over 30 min, followed by a second dose (1000/125 mg) administered orally, separated by a washout period of ≥24 h. We assayed concentrations of amoxicillin by a validated ultra HPLC-tandem MS technique. We estimated population pharmacokinetic parameters of amoxicillin by non-linear mixed-effect modelling using the SAEM algorithm developed by Monolix. RESULTS Twenty-seven subjects were included in the IV study, with 24 included in the oral part of the study. Median body weight and BMI were 109.3 kg and 40.6 kg/m2, respectively. Amoxicillin pharmacokinetics were best described by a two-compartment model with first-order elimination. Mean values for clearance, central volume, intercompartmental clearance and peripheral volume were, respectively, 14.6 L/h, 9.0 L, 4.2 L/h and 6.4 L for amoxicillin. Oral bioavailability of amoxicillin was 79.7%. Amoxicillin Cmax after oral administration significantly reduced with weight (P = 0.013). Dosing simulations for amoxicillin predicted that most of the population will achieve the pharmacodynamic target of fT>MIC ≥40% with the regimen of co-amoxiclav 1000/200 mg (IV) or 1000/125 mg (oral) q8h for MICs titrated up to 0.5 mg/L (IV) and 1 mg/L (oral). CONCLUSIONS Pharmacokinetic/pharmacodynamic goals for amoxicillin can be obtained in obese subjects.
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Affiliation(s)
- G Mellon
- AP-HP, Tropical and Infectious Diseases department, Hôpital Saint-Louis, Paris, France
| | - K Hammas
- CIC-EC 1425, INSERM, F-75018 Paris, France.,AP-HP, Hôpital Bichat, DEBRC, F-75018 Paris, France
| | - C Burdet
- CIC-EC 1425, INSERM, F-75018 Paris, France.,AP-HP, Hôpital Bichat, DEBRC, F-75018 Paris, France.,Université de Paris, IAME, INSERM, F-75018 Paris, France
| | - X Duval
- CIC-EC 1425, INSERM, F-75018 Paris, France.,Université de Paris, IAME, INSERM, F-75018 Paris, France
| | - C Carette
- AP-HP, Nutrition department, Hôpital Georges-Pompidou, Paris, France
| | - N El-Helali
- Microbiology Laboratory, Hôpital Paris Saint Joseph, Paris, France
| | - L Massias
- Université de Paris, IAME, INSERM, F-75018 Paris, France.,AP-HP, Toxicology Laboratory, Hôpital Bichat, Paris, France
| | - F Mentré
- CIC-EC 1425, INSERM, F-75018 Paris, France.,AP-HP, Hôpital Bichat, DEBRC, F-75018 Paris, France.,Université de Paris, IAME, INSERM, F-75018 Paris, France
| | - S Czernichow
- AP-HP, Nutrition department, Hôpital Georges-Pompidou, Paris, France.,Université de Paris, CRESS, INSERM, INRA, F-75004 Paris, France
| | - A-C Crémieux
- AP-HP, Tropical and Infectious Diseases department, Hôpital Saint-Louis, Paris, France
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4
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Veillette JJ, Winans SA, Maskiewicz VK, Truong J, Jones RN, Forland SC. Pharmacokinetics and Pharmacodynamics of High-Dose Piperacillin-Tazobactam in Obese Patients. Eur J Drug Metab Pharmacokinet 2021; 46:385-394. [PMID: 33743171 PMCID: PMC8093170 DOI: 10.1007/s13318-021-00677-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2021] [Indexed: 11/09/2022]
Abstract
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.
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Affiliation(s)
- John J Veillette
- Department of Pharmacy Practice, Loma Linda University School of Pharmacy, Loma Linda, CA, USA.
| | - S Alexander Winans
- Department of Pharmacy Practice, Loma Linda University School of Pharmacy, Loma Linda, CA, USA
| | - Victoria K Maskiewicz
- Department of Pharmaceutical and Administrative Sciences, Loma Linda University School of Pharmacy, Loma Linda, CA, USA
| | - James Truong
- Department of Pharmacy Practice, Loma Linda University School of Pharmacy, Loma Linda, CA, USA
| | | | - Steven C Forland
- Department of Pharmacy Practice, Loma Linda University School of Pharmacy, Loma Linda, CA, USA.,Department of Pharmacy, Loma Linda University Medical Center, Loma Linda, CA, USA.,Loma Linda University School of Medicine, Loma Linda, CA, USA
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5
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Derendorf H, Heinrichs T, Reimers T, Lebert C, Brinkmann A. Calculated initial parenteral treatment of bacterial infections: Pharmacokinetics and pharmacodynamics. GMS INFECTIOUS DISEASES 2020; 8:Doc17. [PMID: 32373442 PMCID: PMC7186811 DOI: 10.3205/id000061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This is the third chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The chapter features the pharmacokinetic and pharmacodynamics properties of the most frequently used antiinfective agents.
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Affiliation(s)
- Hartmut Derendorf
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, USA
| | | | - Tobias Reimers
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, USA
| | | | - Alexander Brinkmann
- Klinik für Anästhesie, operative Intensivmedizin und spezielle Schmerztherapie, Klinikum Heidenheim, Germany
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6
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Mazuski JE, Tessier JM, May AK, Sawyer RG, Nadler EP, Rosengart MR, Chang PK, O'Neill PJ, Mollen KP, Huston JM, Diaz JJ, Prince JM. The Surgical Infection Society Revised Guidelines on the Management of Intra-Abdominal Infection. Surg Infect (Larchmt) 2017; 18:1-76. [PMID: 28085573 DOI: 10.1089/sur.2016.261] [Citation(s) in RCA: 317] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. METHODS Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. RESULTS This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. SUMMARY The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline.
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Affiliation(s)
- John E Mazuski
- 1 Department of Surgery, Washington University School of Medicine , Saint Louis, Missouri
| | | | - Addison K May
- 3 Department of Surgery, Vanderbilt University , Nashville, Tennessee
| | - Robert G Sawyer
- 4 Department of Surgery, University of Virginia , Charlottesville, Virginia
| | - Evan P Nadler
- 5 Division of Pediatric Surgery, Children's National Medical Center , Washington, DC
| | - Matthew R Rosengart
- 6 Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Phillip K Chang
- 7 Department of Surgery, University of Kentucky , Lexington, Kentucky
| | | | - Kevin P Mollen
- 9 Division of Pediatric Surgery, Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Jared M Huston
- 10 Department of Surgery, Hofstra Northwell School of Medicine , Hempstead, New York
| | - Jose J Diaz
- 11 Department of Surgery, University of Maryland School of Medicine , Baltimore, Maryland
| | - Jose M Prince
- 12 Departments of Surgery and Pediatrics, Hofstra-Northwell School of Medicine , Hempstead, New York
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7
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Russell JM, Nick-Dart RL, Nornhold BD. Development of a pharmacist-driven protocol for automatic medication dosage adjustments in obese patients. Am J Health Syst Pharm 2016; 72:1656-63. [PMID: 26386107 DOI: 10.2146/ajhp140315] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
PURPOSE A hospital protocol utilizing automatic dosage adjustments and pharmacist consultations to optimize the use of certain medications in obese patients is described. SUMMARY After conducting a literature search focused on medication dosing in obese patients, pharmacists at a large community hospital developed a list of commonly ordered medications appropriate for inclusion in a pharmacy-driven institutional protocol for automatic medication dosage adjustment in adult patients with obesity. Evidence-based recommendations on initial dosing of eight antimicrobials and two anticoagulant agents according to weight and renal function were formulated. Under the protocol, pharmacists receive electronic alerts regarding protocol-eligible patients during initial order verification and automatically adjust medication dosages as appropriate. For patients prescribed anticoagulants at specified dosage levels, clinical pharmacists consult with prescribers to help ensure safe and effective initial and ongoing therapy. Multidisciplinary educational initiatives were conducted prior to protocol implementation. During two designated three-week postimplementation data collection periods, pharmacists received a total of 372 protocol-eligible medication orders. Pharmacists adjusted a total of 149 dosages and verified an additional 183 dosages consistent with the protocol as originally ordered. Clinical pharmacy consults were completed for 10-15% of patients, with laboratory monitoring ordered in 25-30% of those cases (all patients were found to have appropriate test values). There have been no documented adverse drug reactions in patients whose medication dosages were adjusted per protocol. CONCLUSION Pharmacists implemented weight- and renal function-based dosage adjustments for obese patients in 40% of evaluated protocol-eligible cases to achieve 89% compliance with the protocol. Heparin and cefazolin were the medications most likely to require obesity-related dosage adjustments.
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Affiliation(s)
- Justine M Russell
- Justine M. Russell, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Emergency Department; Rebecca L. Nick-Dart, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Internal Medicine; and Brandon D. Nornhold, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Critical Care, Saint Vincent Hospital, Erie, PA.
| | - Rebecca L Nick-Dart
- Justine M. Russell, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Emergency Department; Rebecca L. Nick-Dart, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Internal Medicine; and Brandon D. Nornhold, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Critical Care, Saint Vincent Hospital, Erie, PA
| | - Brandon D Nornhold
- Justine M. Russell, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Emergency Department; Rebecca L. Nick-Dart, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Internal Medicine; and Brandon D. Nornhold, Pharm. D., BCPS, is Clinical Pharmacy Specialist, Critical Care, Saint Vincent Hospital, Erie, PA
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8
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Dietch ZC, Duane TM, Cook CH, O'Neill PJ, Askari R, Napolitano LM, Namias N, Watson CM, Dent DL, Edwards BL, Shah PM, Guidry CA, Davies SW, Willis RN, Sawyer RG. Obesity Is Not Associated with Antimicrobial Treatment Failure for Intra-Abdominal Infection. Surg Infect (Larchmt) 2016; 17:412-21. [PMID: 27027416 DOI: 10.1089/sur.2015.213] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Obesity and commonly associated comorbidities are known risk factors for the development of infections. However, the intensity and duration of antimicrobial treatment are rarely conditioned on body mass index (BMI). In particular, the influence of obesity on failure of antimicrobial treatment for intra-abdominal infection (IAI) remains unknown. We hypothesized that obesity is associated with recurrent infectious complications in patients treated for IAI. METHODS Five hundred eighteen patients randomized to treatment in the Surgical Infection Society Study to Optimize Peritoneal Infection Therapy (STOP-IT) trial were evaluated. Patients were stratified by obese (BMI ≥30) versus non-obese (BMI≥30) status. Descriptive comparisons were performed using Chi-square test, Fisher exact test, or Wilcoxon rank-sum tests as appropriate. Multivariable logistic regression using a priori selected variables was performed to assess the independent association between obesity and treatment failure in patients with IAI. RESULTS Overall, 198 (38.3%) of patients were obese (BMI ≥30) versus 319 (61.7%) who were non-obese. Mean antibiotic d and total hospital d were similar between both groups. Unadjusted outcomes of surgical site infection (9.1% vs. 6.9%, p = 0.36), recurrent intra-abdominal infection (16.2% vs. 13.8, p = 0.46), death (1.0% vs. 0.9%, p = 1.0), and a composite of all complications (25.3% vs. 19.8%, p = 0.14) were also similar between both groups. After controlling for appropriate demographics, comorbidities, severity of illness, treatment group, and duration of antimicrobial therapy, obesity was not independently associated with treatment failure (c-statistic: 0.64). CONCLUSIONS Obesity is not associated with antimicrobial treatment failure among patients with IAI. These results suggest that obesity may not independently influence the need for longer duration of antimicrobial therapy in treatment of IAI versus non-obese patients.
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Affiliation(s)
- Zachary C Dietch
- 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia
| | - Therese M Duane
- 3 Department of Surgery, Virginia Commonwealth University , Richmond, Virginia
| | - Charles H Cook
- 4 Department of Surgery, Beth Israel Deaconess Medical Center , Boston, Massachusetts
| | - Patrick J O'Neill
- 5 Department of Surgery, Maricopa Integrated Health System , Phoenix, Arizona
| | - Reza Askari
- 6 Department of Surgery, Brigham and Women's Hospital , Boston, Massachusetts
| | - Lena M Napolitano
- 7 Department of Surgery, University of Michigan , Ann Arbor, Michigan
| | - Nicholas Namias
- 8 Department of Surgery, University of Miami Miller School of Medicine , Miami, Florida
| | - Christopher M Watson
- 9 Department of Surgery, University of South Carolina , Columbia, South Carolina
| | - Daniel L Dent
- 10 Department of Surgery, University of Texas Health Science Center at San Antonio , San Antonio, Texas
| | - Brandy L Edwards
- 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia
| | - Puja M Shah
- 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia
| | - Christopher A Guidry
- 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia
| | - Stephen W Davies
- 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia
| | - Rhett N Willis
- 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia
| | - Robert G Sawyer
- 1 Department of Surgery, The University of Virginia Health System , Charlottesville, Virginia.,2 Division of Patient Outcomes, Policy and Population Research, Department of Public Health Sciences, The University of Virginia Health System , Charlottesville, Virginia
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9
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Population pharmacokinetics and pharmacodynamics of piperacillin and tazobactam administered by prolonged infusion in obese and nonobese patients. J Clin Pharmacol 2015; 55:899-908. [DOI: 10.1002/jcph.505] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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10
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Hites M, Taccone FS. Optimization of antibiotic therapy in the obese, critically ill patient. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13546-015-1060-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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11
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Tucker CE, Lockwood AM, Nguyen NH. Antibiotic dosing in obesity: the search for optimum dosing strategies. Clin Obes 2014; 4:287-95. [PMID: 25826157 DOI: 10.1111/cob.12076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 08/01/2014] [Accepted: 09/05/2014] [Indexed: 02/07/2023]
Abstract
Global obesity has nearly doubled and is now a common occurrence in high-income and developing countries. The World Health Organization estimates that more than 1.4 billion adults are obese. Although the prevalence of obesity is increasing over the last decades, pharmacokinetic evaluations are still conducted in individuals with a body weight of approximately 70 kg. Morbid obesity is associated with several pathophysiological changes that can profoundly affect drug distribution and clearance. There are currently no specific dosing recommendations for antibiotics in obese patients, making dosing suggestions primarily based on pharmacokinetic characteristics of the medications and dosing recommendations in other disease states. Understanding of the pharmacokinetic alterations and maximum doses of antibiotics safely used is paramount to appropriate treatment in the obese population.
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Affiliation(s)
- C E Tucker
- Department of Pharmacy, St. Vincent's Medical Center, Jacksonville, FL, USA
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12
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Abstract
Objectives: Obesity may alter the pharmacokinetics of β-lactams. The goal of this study was to evaluate if and why serum concentrations are inadequate when standard β-lactam regimens are administered to obese, non-critically ill patients. Subjects and methods: During first year, we consecutively included infected, obese patients (body mass index (BMI) ⩾30 kg m−2) who received meropenem (MEM), piperacillin-tazobactam (TZP) or cefepime/ceftazidime (CEF). Patients with severe sepsis or septic shock, or those hospitalized in the intensive care unit were excluded. Serum drug concentrations were measured twice during the elimination phase by high-performance liquid chromatography. We evaluated whether free or total drug concentrations were >1 time (fT>minimal inhibition concentration (MIC)) or >4 times (T>4MIC) the clinical breakpoints for Pseudomonas aeruginosa during optimal periods of time: ⩾40% for MEM, ⩾50% for TZP and ⩾70% for CEF. Results: We included 56 patients (median BMI: 36 kg m−2): 14 received MEM, 31 TZP and 11 CEF. The percentage of patients who attained target fT>MIC and T>4MIC were 93% and 21% for MEM, 68% and 19% for TZP, and 73% and 18% for CEF, respectively. High creatinine clearance (107 (range: 6–398) ml min−1) was the only risk factor in univariate and multivariate analyses to predict insufficient serum concentrations. Conclusions: In obese, non-critically ill patients, standard drug regimens of TZP and CEF resulted in insufficient drug concentrations to treat infections due to less susceptible bacteria. Augmented renal clearance was responsible for these low serum concentrations. New dosage regimens need to be explored in this patient population (EUDRA-CT: 2011-004239-29).
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13
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Payne KD, Hall RG. Dosing of antibacterial agents in obese adults: does one size fit all? Expert Rev Anti Infect Ther 2014; 12:829-54. [DOI: 10.1586/14787210.2014.912942] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kenna D Payne
- Texas Tech University Health Sciences Center,
1300 S. Coulter, Rm 323, Amarillo, TX 79106, USA
| | - Ronald G Hall
- Texas Tech University Health Sciences Center,
1300 S. Coulter, Rm 323, Amarillo, TX 79106, USA
- Dose Optimization and Outcomes Research (DOOR) Program,
5920 Forest Park Rd, Suite 400, Dallas, TX 75235, USA
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Gaulton TG, Weiner MG, Morales KH, Gaieski DF, Mehta J, Lautenbach E. The effect of obesity on clinical outcomes in presumed sepsis: a retrospective cohort study. Intern Emerg Med 2014; 9:213-21. [PMID: 24072354 PMCID: PMC5991089 DOI: 10.1007/s11739-013-1002-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 09/12/2013] [Indexed: 12/31/2022]
Abstract
Sepsis is a major cause of hospital admissions and mortality. Nevertheless, there are significant gaps in our knowledge of the epidemiology of sepsis in obese people, who now represent more than one-third of the population in the United States. The objective of this study was to measure the association between obesity and mortality from presumed sepsis. A retrospective cohort study was used of 1,779 adult inpatients with presumed sepsis at a Tertiary Care Academic Institution from March 1, 2007 to June 30, 2011. Cases of sepsis were identified using a standardized algorithm for sepsis antibiotic treatment. Exposure (i.e., obesity) was defined as a body mass index ≥30 kg/m(2). Multivariable logistic regression was used to assess the adjusted association between obesity and mortality. Patients with presumed sepsis were of a median age of 60.9 years (interquartile range 49.7-71) and 41.1 % were women. A total of 393 patients died, resulting in a 28-day in-hospital mortality of 22.1 %. In adjusted analysis, obesity was not significantly associated with increased mortality (odds ratio 1.11, 95 % CI 0.85-1.41, P = 0.47). There was also no difference in the in-hospital length of stay (P = 0.45) or maximum percent change in serum creatinine (P = 0.32) between obese and non-obese patients. Finally, there was no difference in the proportion of initial inadequate vancomycin levels (P = 0.1) after presumed sepsis. Obesity was not associated with increased mortality in patients with presumed sepsis. Further research is needed to determine how excess adiposity modulates inflammation from sepsis.
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Affiliation(s)
- Timothy Glen Gaulton
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, CWN-L 1, Rm L111, 75 Francis Street, Boston, MA, 02115, USA,
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16
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Evaluation of extended interval dosing aminoglycosides in the morbidly obese population. Adv Pharmacol Sci 2013; 2013:194389. [PMID: 24023540 PMCID: PMC3760189 DOI: 10.1155/2013/194389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 07/25/2013] [Accepted: 07/25/2013] [Indexed: 11/18/2022] Open
Abstract
Aminoglycoside dosing has been studied in the obese population, typically recommending an adjusted weight utilizing a 40% dosing weight correction factor (IBW + 0.4 × (TBW-IBW)). These studies included limited numbers of morbidly obese patients and were not done in the era of extended interval aminoglycoside dosing. Here, we report a retrospective evaluation of morbidly obese patients receiving gentamicin or tobramycin at our hospital. The objective of this study was to evaluate the accuracy of the commonly recommended adjusted weight for weight-based dosing. There were 31 morbidly obese patients who received gentamicin or tobramycin 5-7 mg/kg every 24 hours using a 40% dosing weight correction factor. Our institution utilizes 16-hour postdose concentrations to monitor extended interval aminoglycosides. Twenty-two of the 31 patients (71%) achieved an appropriate serum drug concentration. Four patients (13%) were found to be supratherapeutic and 5 patients (16%) subtherapeutic. The only variable that correlated with supratherapeutic levels was older age (P = 0.0378). Our study helps to validate the current dosing weight correction factor (40%) in the morbidly obese population. We recommend caution when dosing aminoglycosides in morbidly obese patients who are of older age.
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Sturm AW, Allen N, Rafferty KD, Fish DN, Toschlog E, Newell M, Waibel B. Pharmacokinetic analysis of piperacillin administered with tazobactam in critically ill, morbidly obese surgical patients. Pharmacotherapy 2013; 34:28-35. [PMID: 23864417 DOI: 10.1002/phar.1324] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
STUDY OBJECTIVE To evaluate the steady-state pharmacokinetic and pharmacodynamic parameters of piperacillin in morbidly obese, surgical intensive care patients. DESIGN Open-label single-center prospective study. SETTING Level I trauma center and university-affiliated teaching institution. PATIENTS Nine morbidly obese (body mass index [BMI] 40.0 kg/m² or higher) hospitalized patients admitted to the trauma and surgical intensive care service who were treated with piperacillin-tazobactam between December 15, 2010, and April 18, 2012. INTERVENTION Patients received intravenous piperacillin-tazobactam 4.5 g every 6 hours, administered as a 30-minute infusion. MEASUREMENTS AND MAIN RESULTS Patients' blood samples were collected after the administration of the fourth, fifth, or sixth dose (i.e., at steady state). Serum piperacillin concentrations were determined by using a validated high-performance liquid chromatography assay; these concentrations were used to estimate pharmacokinetic parameters, and 5000-patient Monte Carlo simulations were performed. The probability of target attainment for 50% or higher of the dosing interval during which free (unbound) drug concentrations exceeded the minimum inhibitory concentration (%fT > MIC) of likely pathogens was calculated for piperacillin at various MICs. Patient demographic and clinical characteristics included a mean ± SD total body weight of 164 ± 50 kg, BMI of 57 ± 15.3 kg/m², and age 57 ± 11 years, and a median Acute Physiology and Chronic Health Evaluation II score of 22 (interquartile range 21-26). Compared with values previously reported in other populations, the volume of distribution was increased in the study patients, and total system clearance was decreased. The net result was a mean ± SD half-life of 3.7 ± 1.2 hours compared with ~1 hour reported in other populations. This contributed to an extended %fT > MIC for likely pathogens. Results from all nine patients showed %fT > MIC of 100% at the susceptibility breakpoint MIC of 16 mg/L and 85% or higher at an MIC of 32 mg/L. CONCLUSION The pharmacokinetics of piperacillin is altered in morbidly obese, surgical intensive care patients. The use of standard-dosage piperacillin-tazobactam 4.5 g intravenously every 6 hours was shown to be an appropriate dosage for this study population.
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Affiliation(s)
- Ashley W Sturm
- Department of Pharmacy, Vidant Medical Center, Greenville, North Carolina
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Cheatham SC, Fleming MR, Healy DP, Chung CE, Shea KM, Humphrey ML, Kays MB. Steady-state pharmacokinetics and pharmacodynamics of piperacillin and tazobactam administered by prolonged infusion in obese patients. Int J Antimicrob Agents 2013; 41:52-6. [DOI: 10.1016/j.ijantimicag.2012.09.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 09/05/2012] [Indexed: 02/06/2023]
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20
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Case-control study of drug monitoring of β-lactams in obese critically ill patients. Antimicrob Agents Chemother 2012; 57:708-15. [PMID: 23147743 DOI: 10.1128/aac.01083-12] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Severe sepsis and septic shock can alter the pharmacokinetics of broad-spectrum β-lactams (meropenem, ceftazidime/cefepime, and piperacillin-tazobactam), resulting in inappropriate serum concentrations. Obesity may further modify the pharmacokinetics of these agents. We reviewed our data on critically ill obese patients (body mass index of ≥ 30 kg/m(2)) treated with a broad-spectrum β-lactam in whom therapeutic drug monitoring was performed and compared the data to those obtained in critically nonobese patients (body mass index of <25 kg/m(2)) to assess whether there were differences in reaching optimal drug concentrations for the treatment of nosocomial infections. Sixty-eight serum levels were obtained from 49 obese patients. There was considerable variability in β-lactam serum concentrations (coefficient of variation of 50% to 92% for the three drugs). Standard drug regimens of β-lactams resulted in insufficient serum concentrations in 32% of the patients and overdosed concentrations in 25%. Continuous renal replacement therapy was identified by multivariable analysis as a risk factor for overdosage and a protective factor for insufficient β-lactam serum concentrations. The serum drug levels from the obese cohort were well matched for age, gender, renal function, and sequential organ failure assessment (SOFA) score to 68 serum levels measured in 59 nonobese patients. The only difference observed between the two cohorts was in the subgroup of patients treated with meropenem and who were not receiving continuous renal replacement therapy: serum concentrations were lower in the obese cohort. No differences were observed in pharmacokinetic variables between the two groups. Routine therapeutic drug monitoring of β-lactams should be continued in obese critically ill patients.
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Abstract
The interactions between obesity and infectious diseases have recently received increasing recognition as emerging data have indicated an association between obesity and poor outcome in pandemic H1N1 influenza infection. Obesity is an established risk factor for surgical-site infections, nosocomial infections, periodontitis and skin infections. Several studies indicate that acute pancreatitis is more severe in the obese. Data are controversial and limited as regards the association between obesity and the risk and outcome of community-acquired infections such as pneumonia, bacteremia and sepsis and obesity and the course of HIV infection. As the cause-effect relationship between obesity and infection remains obscure in many infectious diseases, further studies are warranted. The consequences of obesity may have substantial effects on the global burden of infectious diseases.
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Zakrison TL, Hille DA, Namias N. Effect of Body Mass Index on Treatment of Complicated Intra-Abdominal Infections in Hospitalized Adults: Comparison of Ertapenem with Piperacillin-Tazobactam. Surg Infect (Larchmt) 2012; 13:38-42. [PMID: 22217196 DOI: 10.1089/sur.2010.095] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Tanya L. Zakrison
- Division of General Surgery, St. Michael's Hospital, University of Toronto, Toronto, Canada
| | | | - Nicholas Namias
- Ryder Trauma Center, Department of Trauma and Surgical Critical Care, Miller School of Medicine, University of Miami, Miami, Florida
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Deman H, Verhaegen J, Willems L, Spriet I. Dosing of piperacillin/tazobactam in a morbidly obese patient. J Antimicrob Chemother 2011; 67:782-3. [DOI: 10.1093/jac/dkr503] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
Despite the growing epidemic of obesity in the United States, dosing medications in such patients remains poorly studied and understood. Most recommendations are based on small independent studies, case reports, and expert opinion. Applying manufacturer kinetics and dosing recommendations in the obese patient may result in toxicity or treatment failure, leading to increased morbidity, mortality, and hospital length of stay.
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Chopra T, Zhao JJ, Alangaden G, Wood MH, Kaye KS. Preventing surgical site infections after bariatric surgery: value of perioperative antibiotic regimens. Expert Rev Pharmacoecon Outcomes Res 2010; 10:317-28. [PMID: 20545596 DOI: 10.1586/erp.10.26] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Bariatric surgery for obesity has emerged as an effective and commonly used treatment modality. This paper reviews the surgical site infections (SSIs) that occur post bariatric surgery and SSI prevention. The benefit of bariatric surgery resulting in profound weight loss brings with it consequences in the form of postoperative complications that can have profound effects on morbidity and mortality in these patients. This paper sets out to define different types of SSIs that occur following bariatric surgery and to discuss existing literature on the critical aspects of SSI prevention and the appropriate use of surgical antimicrobial prophylaxis for bariatric surgery.
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Affiliation(s)
- Teena Chopra
- Division of Infectious Diseases, Department of Medicine Wayne State University, Detroit Medical Center, 4201 Saint Antoine, Suite 2B, Box 331, Detroit, MI 48201, USA
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Abstract
Clinical response to medication can differ between patients. Among the known sources of variability is an individual's nutrition status. This review defines some pharmacokinetic terms, provides relevant body size metrics and describes the physiologic influences of protein–energy malnutrition and obesity on drug disposition. Weight-based drug dosing, which presumes a healthy BMI, can be problematic in the protein–energy malnourished or obese patient. The use of total body weight, lean body weight, or an adjusted body weight depends on the drug and how it is differently handled in malnutrition or obesity. Most of the recognized influences are seen in drug distribution and drug elimination as a result of altered body composition and function. Distribution characteristics of each drug are determined by several drug-related factors (e.g. tissue affinity) in combination with body-related factors (e.g. composition). Drug elimination occurs through metabolic and excretory pathways that can also vary with body composition. The current data are limited to select drugs that have been reported in small studies or case reports. In the meantime, a rational approach to evaluate the potential influences of malnutrition and obesity can be used clinically based on available information. Antimicrobials are discussed as a useful example of this approach. Further advancement in this field would require collaboration between experts in body composition and those in drug disposition. Until more data are available, routine monitoring by the clinician of the protein–energy malnourished or obese patient receiving weight-based drug regimens is necessary.
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Hayashi Y, Roberts JA, Paterson DL, Lipman J. Pharmacokinetic evaluation of piperacillin-tazobactam. Expert Opin Drug Metab Toxicol 2010; 6:1017-31. [DOI: 10.1517/17425255.2010.506187] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Arnold A, Brouse SD, Pitcher WD, Hall RG. Empiric therapy for gram-negative pathogens in nosocomial and health care-associated pneumonia: starting with the end in mind. J Intensive Care Med 2010; 25:259-70. [PMID: 20622257 DOI: 10.1177/0885066610371189] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Nosocomial pneumonia is a major cause of morbidity and mortality for hospitalized patients. Antimicrobial resistance is increasing, creating a strain between ensuring the provision of adequate empiric therapy and slowing the development of antimicrobial resistance. Excessive antimicrobial therapy places patients are at greater risk of drug interactions, adverse events, and superinfections. Ways to maximize adequate empiric therapy include (1) categorizing each patient's risk of being infected with a multidrug-resistant pathogen and knowledge of local susceptibility patterns, (2) de-escalating antimicrobial therapy to decrease the rates of superinfections such as Clostridium difficile, and (3) limiting the duration of therapy to decrease the likelihood of adverse events, drug interactions, and antimicrobial resistance. Pharmacodynamically enhanced dosing regimens also have the potential to improve clinical outcomes and slow the development of antimicrobial resistance. Drugs whose killing is optimized by the percentage time above the minimum inhibitory concentration (MIC), such as beta-lactams, can be given by continuous or extended infusion to provide superior pharmacodynamic (PD) target attainment rates compared with traditional regimens. Drugs whose killing is optimized with a high-peak plasma concentration to MIC ratio (eg, aminoglycosides) should be administered once daily to maximize the likelihood of achieve optimal target attainment rates. Drugs whose killing is optimized by the ratio of the area under the curve (AUC) to MIC ratio (eg, fluoroquinolones) depend on the total daily dose as opposed to the dosing schedule or infusion time. Determining the optimal drug dosing schedules for obese patients remains critical because these patients have may have significantly increased volumes of distribution and clearance rates compared to normal weight patients. Optimizing the use of current antimicrobials is paramount to ensure quality treatment options are available, given the lack of gram-negative antimicrobials in the pipeline.
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Affiliation(s)
- Amy Arnold
- Texas Tech University Health Sciences Center, Dallas, TX 75235, USA
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Hanley MJ, Abernethy DR, Greenblatt DJ. Effect of obesity on the pharmacokinetics of drugs in humans. Clin Pharmacokinet 2010; 49:71-87. [PMID: 20067334 DOI: 10.2165/11318100-000000000-00000] [Citation(s) in RCA: 507] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The prevalence of obesity has dramatically increased in recent years and now includes a significant proportion of the world's children, adolescents and adults. Obesity is linked to a number of co-morbidities, the most prominent being type 2 diabetes mellitus. While many agents are available to treat these conditions, the current knowledge regarding their disposition in the obese remains limited. Over the years, both direct and indirect methodologies have been utilized to assess body composition. Commonly used direct measures include underwater weighing, skinfold measurement, bioelectrical impedance analysis and dual-energy x-ray absorptiometry. Unfortunately, these methods are not readily available to the majority of clinicians. As a result, a number of indirect measures to assess body composition have been developed. Indirect measures rely on patient attributes such as height, bodyweight and sex. These size metrics are often utilized clinically and include body mass index (BMI), body surface area (BSA), ideal bodyweight (IBW), percent IBW, adjusted bodyweight, lean bodyweight (LBW) and predicted normal weight (PNWT). An understanding of how the volume of distribution (V(d)) of a drug changes in the obese is critical, as this parameter determines loading-dose selection. The V(d) of a drug is dependent upon its physiochemical properties, the degree of plasma protein binding and tissue blood flow. Obesity does not appear to have an impact on drug binding to albumin; however, data regarding alpha(1)-acid glycoprotein binding have been contradictory. A reduction in tissue blood flow and alterations in cardiac structure and function have been noted in obese individuals. At the present time, a universal size descriptor to describe the V(d) of all drugs in obese and lean individuals does not exist. Drug clearance (CL) is the primary determinant to consider when designing a maintenance dose regimen. CL is largely controlled by hepatic and renal physiology. In the obese, increases in cytochrome P450 2E1 activity and phase II conjugation activity have been observed. The effects of obesity on renal tubular secretion, tubular reabsorption, and glomerular filtration have not been fully elucidated. As with the V(d), a single, well validated size metric to characterize drug CL in the obese does not currently exist. Therefore, clinicians should apply a weight-normalized maintenance dose, using a size descriptor that corrects for differences in absolute CL between obese and non-obese individuals. The elimination half-life (t((1/2))) of a drug depends on both the V(d) and CL. Since the V(d) and CL are biologically independent entities, changes in the t((1/2)) of a drug in obese individuals can reflect changes in the V(d), the CL, or both. This review also examines recent publications that investigated the disposition of several classes of drugs in the obese--antibacterials, anticoagulants, antidiabetics, anticancer agents and neuromuscular blockers. In conclusion, pharmacokinetic data in obese patients do not exist for the majority of drugs. In situations where such information is available, clinicians should design treatment regimens that account for any significant differences in the CL and V(d) in the obese.
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Affiliation(s)
- Michael J Hanley
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine and Tufts Medical Center, Boston, Massachusetts 02111, USA
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