Apparent volume of distribution (Vd) Definition:
A pharmacokinetic parameter that describes the apparent volume into which a drug distributes.
Apparent volume of distribution is a ratio of the total amount of drug in the body to the plasma concentration of the drugs such that Vd = amount of drug in body/plasma drug concentration. Volume of distribution is not a physical, anatomical space; rather it is a calculated volume that helps determine the relative distribution of a drug within the body. Apparent volume of distribution is important for determining the dose required to produce a desired plasma concentration of the drug.
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