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 based on actual body weight.

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.