Pharmacology & Dosage
Basic

Volume of Distribution

Apparent volume into which a drug distributes — a larger Vd means the drug leaves the bloodstream and enters tissues.

Formula

Vd=DC0V_d = \frac{D}{C_0}

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Variables

V_dVolume of distribution (L)
DDose administered (IV bolus)
C_0Initial plasma concentration

Example

500 mg IV → C₀ = 10 mg/L → Vd = 50 L

Did You Know?

Chloroquine has a Vd of over 200 L/kg — far exceeding total body water — because it concentrates heavily in tissues.

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