Kenna D. Payne

Multicenter Evaluation of Vancomycin Dosing – Emphasis on Obesity

BACKGROUND There is a paucity of data available regarding the dosing of antimicrobials in obesity. However, data are available demonstrating that vancomycin should be dosed on the basis of actual body weight. METHODS This study was conducted at 2 tertiary care medical centers that did not have pharmacy-guided vancomycin dosing programs or other institutional vancomycin dosing policies or protocols. Patients who received vancomycin between July 1, 2003, and June 30, 2006, were stratified by body mass index and randomly selected from the computer-generated queries. Patients >or=18 years of age with a creatinine clearance of at least 60 mL/min who received vancomycin for at least 36 hours were included. RESULTS Data were collected on a random sampling of 421 patients, stratified by body mass index, who met the inclusion criteria. Most patients in each body mass index category received a fixed dose of vancomycin 2 g daily divided into 2 doses (underweight 82%, normal weight 90%, overweight 86%, and obese 91%). Adequate initial dosing (>or=10 mg/kg/dose) was achieved for 100% of underweight, 99% of normal weight, 93.9% of overweight, and 27.7% of obese patients (P < .0001). Ninety-seven percent of underweight, 46% of normal weight, 1% of overweight, and 0.6% of obese patients received >or=15 mg/kg/dose recommended by several Infectious Diseases Society of America guidelines. Pharmacists also failed to correct inadequate dosing because only 3.3% of patients receiving less than 10 mg/kg/dose had their regimen changed in the first 24 hours of therapy. CONCLUSION In this multicenter pilot study, obese patients routinely received inadequate empiric vancomycin using a lenient assessment of dosing. Greater efforts should be undertaken to ensure patients receive weight-based dosing because inadequate dosing can lead to subtherapeutic concentrations and potentially worse clinical outcomes.

Lipid-Lowering Efficacy and Safety After Switching to Atazanavir-Ritonavir-Based Highly Active Antiretroviral Therapy in Patients with Human Immunodeficiency Virus

Study Objective. To evaluate the efficacy, safety, and lipid‐lowering effects after switching from a non‐atazanavir‐containing, protease inhibitor‐based highly active antiretroviral therapy (HAART) to atazanavir‐ritonavir‐based HAART in patients infected with human immunodeficiency virus (HIV).

Safety and efficacy of simvastatin for the treatment of dyslipidemia in human immunodeficiency virus-infected patients receiving efavirenz-based highly active antiretroviral therapy.

Study Objectives. To evaluate the safety and efficacy of simvastatin for treatment of dyslipidemia in patients with the human immunodeficiency virus (HIV) who were receiving efavirenz‐based highly active antiretroviral therapy (HAART), and to evaluate the effect of simvastatin when added to efavirenz on CD4+ count, HIV viral load, and frequency of attainment of patient‐specific National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III lipid goals.

Dosing of antifungal agents in obese people

ABSTRACT Obesity is a worldwide epidemic associated with multiple comorbidities that increase the risk of hospitalization. Very little pharmacokinetic data are available for antifungal agents in obesity, as this population is often excluded from drug development studies and these agents are less commonly used than other antimicrobials. Systemic antifungal therapy for invasive candidiasis continues to have a high failure rate, and dose optimization in obesity provides an opportunity for improvement. Based on currently available data, some antifungals should be dosed based on total body weight (i.e. fluconazole), while others should not be adjusted for increased body weight (i.e. posaconazole). More studies are needed to determine if and when dosing changes are needed for many of the antifungal agents. Therefore, drug therapy regimens should be individually evaluated for dose optimization due to body weight.

Dosing of antibacterial agents in obese adults: does one size fit all?

Obesity is a global pandemic affecting 33% of adults in the United States. Obese persons receiving cefazolin or fluconazole have been shown to have worse outcomes with suboptimal dosing. Studies evaluating the safety of colistin, daptomycin, and vancomycin have shown increased weight or obesity may potentially increase toxicity. Many antimicrobials lack pharmacokinetic data to support dose individuation in obese persons, due in part to the lack of obese patients in drug development studies. A one size fits all approach to dose optimization for obese patients is not likely. Current expert opinion suggests some antimicrobials (i.e. vancomycin) be dosed according to total body weight, whereas others (i.e. aminoglycosides) require adjusted body weight for dose calculations. Yet other antimicrobials are reported to need no dose adjustment, largely based on studies using body mass index groups. Therefore, each drug should be individually evaluated to determine the proper dose for obese persons.

Dosing strategies to optimize currently available anti-MRSA treatment options (Part 1: IV options)

ABSTRACT Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a predominant pathogen resulting in significant morbidity and mortality. Optimal dosing of anti-MRSA agents is needed to help prevent the development of antimicrobial resistance and to increase the likelihood of a favorable clinical outcome. Areas covered: This review summarizes the available data for antimicrobials routinely used for MRSA infections that are not administered orally or topically. We make recommendations and highlight the current gaps in the literature. A PubMed (1966 – Present) search was performed to identify relevant literature for this review. Expert commentary: Improvements in MIC determination and therapeutic drug monitoring are needed to fully implement individualized dosing that optimizes antimicrobial pharmacodynamics.Additional data will become available for these agents in regards to effectiveness for severe MRSA infections and pharmacokinetic data for special patient populations.

Multi-state medication take back initiative: Controlled substances collected from 2011 to 2015

ABSTRACT It is important to assess which dispensed medications remain unused as accumulated home medications serve as a source for poisonings, abuse, and misuse. The objective of this study was to characterize and quantify controlled substances relinquished at community medication take back events. Medications were brought to events from 2011 to 2015 across six states. We analyzed medication classification (over-the counter, controlled, non-controlled), medication name, strength, formulation, original dispensed quantity, collected quantity, and therapeutic class. The top nine controlled therapeutic class categories are reported in this study, excluding liquid formulations. The total number of collected controlled prescriptions and units (tablets/capsules/patches) were calculated. Averages are presented for dispensed and collected quantity, and percent waste (unused) for medication categories. Over 10,270 prescriptions with 280,813 units were collected and logged. With 85 units per prescription, morphine had the greatest average originally dispensed units. Hydrocodone had the greatest quantity of prescriptions (4,717), containing 104,460 units. Pregabalin had the highest waste at 74.8%, followed by fentanyl patches (70.1%) and morphine (68.4%). Of the medications returned, more than half of the originally dispensed prescriptions for all medication categories remained unused. All aspects of controlled substance supply and demand should be scrutinized to address this public health epidemic while ensuring optimal patient care.