Antimicrobial Use Guidelines (AMUG) version 21 - UW Health

CommentsFood and/or acid is required for the absorption of posaconazole; 15 grams of fat are necessary for maximal absorption ofa dose. A meal, nutritional supplement shake or serving of ice cream should be provided with each dose. Ideally, PPIacid suppressants should be avoided, or another class, i.e., histamine H 2 -blockers, substituted to maximize absorption.Jacqueline Sullivan, RD, kindly provided the following list of fat content in Room Service foods and supplements:• 2 cartons whole milk = 16 g• 1 serving French fries = 19 g• 2 – 1 oz slices cheese = 15 g• 1 serving cheeseburger = >15 g• 2 packets (2 Tbsp.) peanut butter = 15 g• 1 serving hot dog = > 15 g• 1 Tbsp. cooking oil or olive oil = 14 g• 1 serving fried chicken breast sandwich = > 15g• 4 pats butter = 16 g• 1 serving Ensure Plus (240 mL) = 11 g• 1 croissant = 19 g• 1 serving Magic Cup = 11 g• 1 serving brownie = 22 g• 1 serving Scandishake (240 mL) = 31 g• 1 serving cherry pie = 14 g• 1 serving Ensure High Protein (240 mL) = 6 g• 1 serving apple cinnamon coffee cake = 23 g• 1 serving Enlive = 0 g• 1 package brown sugar Pop-Tart = 14 g• 1 chocolate chip cookie = 10 gDrug InteractionsPosaconazole is an inhibitor of CYP3A4; concomitant administration of other CYP3A4 substrates may result in increasedplasma levels of those drugs, leading to adverse reactions. The following list of drugs are CYP3A4 substrates that maycause QT interval prolongation and potentially torsades de pointes when serum levels are increased, thus concomitantadministration with posaconazole is contraindicated:• astemizole• cisapride• halofantrine• pimozide• quinidine• terfenadineThe following drugs may have their levels increased by CYP3A4 inhibition with posaconazole; there is the potential forincreased toxicity so caution and increased vigilance are indicated:• Amlodipine • Felodipine • Rifabutin• Atazanavir • Lercanidipine • Ritonavir• Cyclosporine • Midazolam • Sirolimus• Diltiazem • Nifedipine • Tacrolimus• Ergot alkaloids • Nisoldipine • Verapamil• Etravirine • Nitrendipine • Vinca alkaloids• Everolimus • PhenytoinThe following drugs decrease serum levels of posaconazole when administered concurrently:• Efavirenz – induces glucuronidation elimination pathway• Metoclopramide – due to decreased GI motility• Phenytoin – induces metabolism• Rifabutin – induces metabolismMiscellaneous drug interactions with posaconazole are as follows:• Digoxin – increased digoxin serum levels with concurrent administration• Topiramate – increased topiramate serum levels with concurrent administration