Ideal Body Weight (Devine Formula)
Ideal and adjusted body weight for drug dosing.
About this calculator
Ideal Body Weight (IBW) by the Devine formula – calculates ideal weight for drug dosing. Developed by Devine (Drug Intell Clin Pharm, 1974) for gentamicin dosing in obesity. Formula. Men: IBW = 50 + 2.3 × (height in inches – 60). Women: IBW = 45.5 + 2.3 × (height in inches – 60). When height is in cm: inches = cm / 2.54. Clinical use. Drug dosing in obese patients. Drugs distributing into fat (lipophilic – propofol, midazolam, digoxin) – use actual body weight. Drugs distributing into lean mass (hydrophilic – aminoglycosides, vancomycin, non-specific anesthetics) – use IBW or adjusted body weight (IBW + 0.4 × (actual – IBW)). Other formulas. Robinson – slightly higher than IBW for men. Miller – slightly lower. Hamwi – popular US quick estimate (men 48 kg + 2.7 kg per inch above 152 cm, women 45 kg + 2.2 kg per inch). Current ASHP 2020 guidance recommends Devine as standard. Examples. 175 cm man – 175/2.54 = 68.9 inches, IBW = 50 + 2.3 × (68.9-60) = 70.5 kg. 165 cm woman – 65 inches, IBW = 45.5 + 2.3 × 5 = 57 kg. Limitations. Not used in patients under 152 cm or under 18 – formula not validated. In amputees adjust for missing mass. In pregnancy and patients with ascites or severe edema – actual weight is distorted. In very thin patients (BMI <18.5) dose by actual weight, not IBW.
Source
Devine BJ. Gentamicin therapy. Drug Intell Clin Pharm. 1974;8:650-655.
Formula version: devine-1974-v1
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