MedCalc: Vancomycin Pharmacokinetics
* = minimum information needed for Revision calculations

Step 1 : Patient Information :
Gender : Age : years
Weight : Serum Creatinine :
Height :
Ideal Body Weight : kg
CrCl : ml/min CrCl : L/hr
* Vd : L * Kel : hr-1
t½ : hr

Step 2 : Based on displayed / current dose :
Dose : mg * t :
 hr ( usu. 1-2 x t ½ ) ( i.e. q12º, q24º, q48º )
* Target Cpss trough : mg/L * Time 'peak' obtained : hr   (usu. 1 hr + infusion time)
or
Cpss max : mg/L Cpss min : mg/L

Step 3 : Revisions :
Actual 'trough' level : mg/L Time 'trough' obtained : hrs before (+) / after (-) t

If 'trough' were drawn on-time :
kel =
ln(
 dose / Vd + C (trough) C (trough)
) t
Revised k : hr-1
Revised t½ : hr
(from Step 2)   Dose : mg
'Trough' not drawn on-time :
Cp (estim trough) = Cp0 ( e - kt )

Revised k =
ln(
 Cpss max Cp (estim trough)
) t - 2

Estimated trough (Cp) : mg/L
Revised k : hr-1
Revised t½ : hr
(from Step 2)   Dose : mg
Cpss-anytime (mg/L) =
 Dose ( e - kt ) Vd ( 1 - e - kt )
Revised k : hr-1
Revised t½ : hr
(from Step 2)   Dose : mg
Cockcroft-Gault : GFR =
 (140 - age) x weight (kg) PCr x 72
x 0.85 (for women)
Vd (L) =  0.7 (L/kg) x (actual body weight)
kel (hr-1) =
 CrCl (L/hr) Vd (L)
t½ (hr) =
 0.693 kel (hr-1)
Dose (mg) =
 Cpss x Vd x ( 1 - e - kt ) e - kt
Cpss max (mg/L) =
 Dose ( e - kt ) Vd ( 1 - e - kt )
Cpss min (mg/L) =
 Dose ( e - kt ) Vd ( 1 - e - kt )
kel =
ln(
 dose / Vd + C (trough) C (trough)
) t

Created: Tuesday, January 9, 2001