Obesity is associated with an increased risk of infection. Unfortunately clinical trials examining the safety and efficacy of antibiotics in obese patients are deficient. Thus, clinicians predominately rely on pharmacokinetic and pharmacodynamic data for appropriate antibiotic dosing. The current literature for vancomycin, aminoglycosides, beta-lactams, fluoroquinolones, linezolid, and macrolides was reviewed to evaluate appropriate dosing in obese patients. Due to the limited number of studies and various pharmacokinetic parameters of antibiotics, dosing should be based on both patient- and drug-specific factors.
Obesity is a growing problem in the United States. Currently, 68% of adult Americans are overweight (BMI >25 kg/m2).1 Of those, 35% are obese (BMI >30 kg/m2) and 6% are morbidly obese (BMI >40 kg/m2). It is estimated that by 2030, 51% of the population will be obese and 11% will be morbidly obese.1 We are often confronted with dosing drugs in an obese patient. Unfortunately, many clinical trials exclude or have limited overweight patients enrolled; thus, optimal dosing for both safety and efficacy in this population is lacking. Pharmacokinetic studies in obese patients have shown that the volumes of distribution of lipophilic drugs and the clearance of hydrophilic drugs can be increased. For this reason, dosing in obesity should be patient- and drug-specific.