Example: Amrinone is a drug used to improve the cardiac output through its vasodilatation and positive inotropic actions. Its Vd is 2 L/kg and elimination rate constant is 0.16 hr-1. Recommend an iv loading dose and an infusion rate to maintain amrinone plasma conc at 1.5mg/L.
Loading dose:
= 1.5mg/L X 2 L/kg = 3 mg/kg
Infusion rate:
= 1.5mg/L X 2 L/kg X 0.16 hr-1
=0.48 mg/kg/hr