Appendix B. Selecting Appropriate Dosing Weight for Antimicrobial Medications From: Renal Function-Based Dose Adjustments – Adult – Inpatient/Ambulatory – Consensus Care Model Contact for Content: Lucas Schulz, PharmD, BCPS (AQ-ID); 608-890-8617; LSchulz2@uwhealth.org Definitions and Equations: • TBW = Total body weight (also called “Actual Body Weight”) • IBW = ideal body weight o IBW in kg (male) = 50 𝑘𝑘𝑘𝑘 + 2.3 × [𝐻𝐻𝑎𝑎𝑖𝑖𝑘𝑘ℎ𝐻𝐻 (𝑖𝑖𝑖𝑖𝐵𝐵ℎ𝑎𝑎𝑒𝑒)− 60] o IBW in kg (female) = 45.5 𝑘𝑘𝑘𝑘 + 2.3 × [𝐻𝐻𝑎𝑎𝑖𝑖𝑘𝑘ℎ𝐻𝐻 (𝑖𝑖𝑖𝑖𝐵𝐵ℎ𝑎𝑎𝑒𝑒)− 60] • AdjBW = adjusted body weight o AdjBW in kg = 𝐼𝐼𝐴𝐴𝐴𝐴(𝑘𝑘𝑘𝑘) + 0.4 × [𝐴𝐴𝐴𝐴𝐴𝐴(𝑘𝑘𝑘𝑘)− 𝐼𝐼𝐴𝐴𝐴𝐴(𝑘𝑘𝑘𝑘)] Appendix B: Selecting appropriate dosing weight for antimicrobial dosing (all recommendations are UW Health GRADE Low-moderate quality evidence, conditional recommendation) If patient TBW less than IBW, use this column If patient is non- obese and TBW is greater than IBW, use this column If patient is obese (BMI >30 kg/m2), use this column Antibiotics Aminoglycosides TBW IBW AdjBW1 Colistin IBW IBW2,3 Daptomycin IBW IBW4 Polymyxin B TBW AdjBW5-9 Trimethoprim/Sulfamethoxazole TBW AdjBW10 Vancomycin TBW TBW11,12 Antivirals Acyclovir TBW IBW IBW10 Ganciclovir TBW AdjBW10 Foscarnet TBW AdjBW 10; see footnote A Antifungals Liposomal amphotericin TBW TBW AdjBW 13; see footnote B Flucytosine IBW IBW14,15 Voriconazole TBW AdjBW16,17 Miscellaneous Bezlotoxumab TBW TBW TBW13 Ethambutol IBW IBW14 Pyrazinamide IBW IBW14,15 A Use TBW for the indication of ganciclovir-resistant cytomegalovirus B Consider IBW if risk of nephrotoxicity outweighs risk of infection Copyright © 2020 University of Wisconsin Hospitals and Clinics Authority. All Rights Reserved. Printed with Permission Contact: CCKM@uwhealth.org Last Revised: 08/2020 Effective 12/15/2020. Contact CCKM@uwhealth.org for previous versions Appendix B References 1. Bauer LA, Edwards WA, Dellinger EP, Simonowitz DA. Influence of weight on aminoglycoside pharmacokinetics in normal weight and morbidly obese patients. European journal of clinical pharmacology. 1983;24(5):643-647. 2. Garonzik SM, Li J, Thamlikitkul V, et al. Population pharmacokinetics of colistin methanesulfonate and formed colistin in critically ill patients from a multicenter study provide dosing suggestions for various categories of patients. Antimicrobial agents and chemotherapy. 2011;55(7):3284-3294. 3. Ortwine JK, Kaye KS, Li J, Pogue JM. Colistin: understanding and applying recent pharmacokinetic advances. Pharmacotherapy. 2015;35(1):11-16. 4. Ng JK, Schulz LT, Rose WE, et al. Daptomycin dosing based on ideal body weight versus actual body weight: comparison of clinical outcomes. Antimicrobial agents and chemotherapy. 2014;58(1):88-93. 5. Sandri AM, Landersdorfer CB, Jacob J, et al. Population pharmacokinetics of intravenous polymyxin B in critically ill patients: implications for selection of dosage regimens. Clin Infect Dis. 2013;57(4):524-531. 6. Pai MP. Polymyxin B dosing in obese and underweight adults. In: Clin Infect Dis. Vol 57. United States2013:1785. 7. Onufrak NJ, Rao GG, Forrest A, et al. Critical Need for Clarity in Polymyxin B Dosing. Antimicrob Agents Chemother. 2017;61(5). 8. Pogue JM, Ortwine JK, Kaye KS. Are there any ways around the exposure-limiting nephrotoxicity of the polymyxins? Int J Antimicrob Agents. 2016;48(6):622-626. 9. Pogue JM, Ortwine JK, Kaye KS. Clinical considerations for optimal use of the polymyxins: A focus on agent selection and dosing. Clin Microbiol Infect. 2017;23(4):229-233. 10. Polso AK, Lassiter JL, Nagel JL. Impact of hospital guideline for weight-based antimicrobial dosing in morbidly obese adults and comprehensive literature review. Journal of clinical pharmacy and therapeutics. 2014;39(6):584-608. 11. Rybak MJ, Lomaestro BM, Rotschafer JC, et al. Therapeutic monitoring of vancomycin in adults summary of consensus recommendations from the American Society of Health-System Pharmacists, the Infectious Diseases Society of America, and the Society of Infectious Diseases Pharmacists. Pharmacotherapy. 2009;29(11):1275- 1279. 12. Srinivas NR. Influence of Morbidly Obesity on the Clinical Pharmacokinetics of Various Anti-Infective Drugs: Reappraisal Using Recent Case Studies-Issues, Dosing Implications, and Considerations. American journal of therapeutics. 2016. 13. Amsden JR, Slain D. Antifungal Dosing in Obesity: A Review of the Literature. Current Fungal Infection Reports. 2011;5(2):83. 14. Vermes A, Guchelaar HJ, Dankert J. Flucytosine: a review of its pharmacology, clinical indications, pharmacokinetics, toxicity and drug interactions. The Journal of antimicrobial chemotherapy. 2000;46(2):171- 179. 15. Tucker CE, Lockwood AM, Nguyen NH. Antibiotic dosing in obesity: the search for optimum dosing strategies. Clinical obesity. 2014;4(6):287-295. 16. Koselke E, Kraft S, Smith J, Nagel J. Evaluation of the effect of obesity on voriconazole serum concentrations. The Journal of antimicrobial chemotherapy. 2012;67(12):2957-2962. 17. Sebaaly JC, MacVane SH, Hassig TB. Voriconazole concentration monitoring at an academic medical center. American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists. 2016;73(5 Suppl 1):S14-21. Copyright © 2020 University of Wisconsin Hospitals and Clinics Authority. All Rights Reserved. Printed with Permission Contact: CCKM@uwhealth.org Last Revised: 08/2020 Effective 12/15/2020. Contact CCKM@uwhealth.org for previous versions Appendix B. Selecting Appropriate Dosing Weight for Antimicrobial Medications