Inotropes

NORMAL RANGE

Dopamine & dobutamine = 5-20mcg/kg/min

Noradrenaline                  = 0.05-0.5mcg/kg/min

Adrenaline                        = 1-20mcg/min (NOT/kg)

PREPARATION

Dopamine (1vial)         = 200mg in 5cc

Dobutamine  (1vial)     = 250mg in 20cc

Noradrenaline (1vial)   = 1mg in 1cc

FORMULA 1

choose desired rate (in mcg/kg/min)

rate (mL/H) = desired rate (in mcg/kg/min) x 60 x Wt (kg)

                                 drug concentration (mcg/mL)

e.g. dopamine @ 5mcg/kg/min in 40kg using dopamine 400mcg/ml

        rate (mL/H) = 5x60x40/400 = 30mL/H

Advantage of this formula

avoid wastage of drug as all the drugs contained in the vials used in the dilution

FORMULA 2

1. Dopamine and dobutamine

    3 x Wt (kg) = X mg

    X mg dilute in 50cc NS/DS

    Rate

    1mL/H = 1mcg/kg/min 

2.  Noradrenaline 

  

      0.3 x Wt (kg) = X mg

      X mg dilute in 50cc D5%

      Rate

      1mL/H = 0.1mcg/kg/min 

Advantage: Standardise rate

Disadvantage: Wastage of drugs (only X mg used for dilution)