NOTE:  These equations are not to be used in children, infants, or
       neonates.

General:

IBW = 50 Kg + (2.3 x Inches over 5 ft) [Males]
IBW = 45.5 Kg + (2.3  x Inches over 5 ft) [Females]
DOSING WEIGHT = (PATIENT WEIGHT - IBW) * 0.4 +IBW
                         
       (140 - Age) x IBW*
CrCl = ------------------ [x 0.85 for females]
          72 x SCr


(* if actual weight less than IBW actual weight is used for calculation)

AMINOGLYCOSIDES (First order/one compartment equations):
VANCOMYCIN


Assumptions:
  The equations assume that steady state has been achieved.
  If steady state has not been achieved, then a pre-dose
  C(min) should be used in place of the C(min-actual)
  in the Vd equation.

Definitions:
  Ke = elimination rate constant
  CrCl = creatinine clearance
  IBW = ideal body weight
  C1 = first concentration
  C2 = second concentration
  T1 = time of C1
  T2 = time of C2
  LD = loading dose
  C(desired) = desired level
  T(inf) = time of infusion or time to peak level
  Tau = dosing interval
  C(max) = maximum serum concentration
  C(min) = minimum serum concentration
  Cx = any given concentration
  Tx = time of Cx
  Vd = volume of distribution in liters
  MD = maintenance dose




Ke = 0.014 + (0.00293 x CrCl) [Tobramycin/Gentamicin]
Vd= 0.28 * body weight(selected) [Tobramycin/Gentamicin]


Ke = (0.00083 x CrCl) +0.0044   [Vancomycin]
Vd= 0.60 * body weight(selected) [Vancomycin]


      ln C1 - ln C2
Ke = ---------------
         t2 - t1

     Vd x T(inf) x Ke x C(desired)
LD = ------------------------------
            -Ke x T(inf)
       1 - e

       1       C(max)
Tau = --- x ln ------ + T(inf)
      Ke      C(min)


                -Ke x Tau
MD = LD x (1 - e          )


 


                 -Ke x T(inf)
      MD x (1 - e             )
Vd(l)=-----------------------------------------------------------------
                                          -Ke x T(inf)
      Ke x T(inf) x [C(max) - (C(min) x e             )]


                                        -Ke x Tau
     C(max) x Ke x T(inf) x Vd x (1 - e          )
MD = ----------------------------------------------
                    -Ke x T(inf)
               1 - e



                    -Ke x T(inf)
         MD x (1 - e             )
C(max) = -------------------------
                                   -Ke x Tau
         Ke x T(inf) x Vd x (1 - e          )


          -Ke x (Tau - T(inf))
C(min) = e                      x C(max)