Dosing of antimicrobials in obesity
From IDWiki
Calculating Body Weight
| Statistic | Equation (Male) | Equation (Female) | Notes |
|---|---|---|---|
| Body mass index (BMI) (kg/m2) | weight, kg / (height, m)2 | ||
| Body surface area (BSA) (m2) | (height, cm × weight, kg / 3600)1/2 | ||
| Ideal body weight (IBW) (kg) | 50 + 2.3 × (inches over 5 ft) | 45.5 + 2.3 × (inches over 5 ft) | |
| Adjusted body weight (ABW) (kg) | IBW + C × (TBW - IBW) | C = 0.3 to 0.4 | |
| Lean body weight (LBW) (kg) | 9270 × TBW / 6680 + 216 x BMI | 9270 × TBW / 8780 + 244 x BMI | |
| Fat-free weight (FFW) (kg) | 0.00139 × (height, cm)2 - 0.0801 × R + 0.187 × TBW + 39.83 | 0.00151 × (height, cm)2 - 0.0344 × R + 0.14 × TBW - (0.158 × age) + 20.387 | R = resistance |
Antibiotics
Penicillins
| Drug | Usual Dose | Obesity | Max dose |
|---|---|---|---|
| Amoxicillin | 1 g PO q8h | No data | |
| Ampicillin | 2 g IV q4h | ||
| Nafcillin | 2 g IV q4h | No data | |
| Piperacillin-tazobactam | 4.5 g IV q6-8h | Prolonged infusion | 18 g daily |
Cephalosporins
| Drug | Usual Dose | Obesity | Max dose |
|---|---|---|---|
| Cefazolin | 1-2 g IV q8h | 2-3 g IV q6-8h | No data; 12 g daily |
| Cephalexin | 500-1000 g PO qid | 1000 g PO qid | No data |
| Cefipime | 2 g IV q8h | 2 g IV q8h prolonged infusion | 2 g IV q8h prolonged infusion |
| Ceftazidime | 2 g IV q8h | 2 g IV q8h prolonged infusion | 2 g IV q8h prolonged infusion |
| Ceftazidime-avibactam | Usual dose | ||
| Ceftolozane-tazobactam | Usual dose |
Carbapenems
| Drug | Usual Dose | Obesity | Max dose |
|---|
Quinolones
| Drug | Usual Dose | Obesity | Max dose |
|---|
Quinolones
| Drug | Usual Dose | Obesity | Max dose |
|---|
Macrolides
| Drug | Usual Dose | Obesity | Max dose |
|---|
Tetracyclines
| Drug | Usual Dose | Obesity | Max dose |
|---|
Others
| Drug | Usual Dose | Obesity | Max dose |
|---|
Further Reading
- Comprehensive Guidance for Antibiotic Dosing in Obese Adults. Pharmacotherapy. 2017;37(11):1415-1431. doi: 10.1002/phar.2023
