Dosing Weights

Different weights should be used for drugs dosed on a mg/kg basis depending on the physicochemical properties of the drug, as noted in the table below. For patients with extreme obesity or who are significantly underweight, or if toxicity is suspected, consult ID Pharmacy for dosing assistance.

Ideal and adjusted body weight calculator.

Drug Name Adjustment in Obesity
Acyclovir IV
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
AmBisome (liposomal amphotericin B)
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Amikacin
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Cidofovir
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Colistin IV
Ideal Body Weight when patient weight >120% of ideal body weight
Daptomycin
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Flucytosine
Ideal Body Weight when patient weight >120% of ideal body weight
Foscarnet
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Ganciclovir
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Gentamicin
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Pentamidine IV
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Plazomicin
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Polymyxin B
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
TMP/SMX (trimethoprim/sulfamethoxazole)
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Tobramycin
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight
Voriconazole
Adjusted Body Weight when patient weight >120% of ideal body weight
Total Body Weight