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General medicine

Ideal and Adjusted Body Weight (Devine)

Fraction of the excess weight added to the IBW; 0.4 is the common convention.

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Formula

IBW (male) = 50 + 2.3 x (height in inches - 60); IBW (female) = 45.5 + 2.3 x (height in inches - 60). Adjusted weight = IBW + 0.4 x (actual weight - IBW).

Limitations

  • The Devine formula was derived for drug dosing in adults; below 60 inches the linear extrapolation is unreliable (flagged in the details).
  • The 0.4 adjustment factor and the 120%-of-IBW threshold are conventions that vary by institution and drug; they are not part of the original paper.

References

  1. Gentamicin therapy. Devine BJ. Drug Intell Clin Pharm. 1974;8:650-655.
  2. The origin of the "ideal" body weight equations. Pai MP, Paloucek FP. Ann Pharmacother. 2000;34(9):1066-1069. PMID 10981254