The initial volume of distribution (Vi) is a pharmacological term used to quantify the distribution of a drug throughout the body relatively soon after oral or intravenous dosing of a drug and prior to the drug reaching a steady state equilibrium.
The term "initial volume of distribution" (Vi) describes the amount of a drug that is distributed into tissues and fluids within the body immediately after it's administered orally or intravenously. This measurement helps determine how quickly a drug reaches its target site in the body.