Volume of distribution

Under the volume of distribution ( Vd), also known as apparent volume of distribution, is understood in pharmacokinetics, a branch of pharmacology, the notional volume of a human or animal body, into which a given drug or drug would distribute to the observed concentration in the blood plasma to explain. The volume of distribution is to be understood as a pure mathematical parameter. It represents a ratio relating the dose of an administered active ingredient to the concentration in the blood plasma in the relationship:

Unit for the distribution volume is the liter, often referred to as liters / kg (normalized to body mass) specified. Depending on the lipid solubility ( lipophilicity ) or water solubility of a drug volume of distribution can vary in size and include making volumes that are significantly larger than the body volume for the same organism for various active ingredients.

Volumes of distribution play an important role in multi -compartment models of pharmacokinetics; A compartment has train counts, mainly a certain volume of distribution and clearance.

Are thereby the central volume of distribution ( ), in which a drug is distributed rapidly after absorption into the body, the volume of distribution at steady state: a distinction that is taken after the distribution in the body. As the volume of distribution is referred to in the final phase of the terminal elimination.