Pharmacology Corner

Pharmacology CME for physicians, pharmacists and nurses.

Loading dose definition

The following pharmacology definition has been taken from the Pharmacology and Experimental Therapeutics Department Glossary at Boston University School of Medicine.

Loading Dose:

A larger than normal dose (D*) administered as the first in a series of doses, the others of which are smaller than D* but equal to each other. The loading dose is administered in order to achieve a therapeutic amount in the body more rapidly than would occur only by accumulation of the repeated smaller doses. The smaller doses (D) which are given after D* are called “maintenance doses”. The effect of D* on C becomes relatively less with each succeeding maintenance dose; finally Css,max and Css,min are determined by D, and are uninfluenced by D*.

The relative sizes of D and D* can be adjusted so that peak plasma concentrations (Cmax) are the same following every dose, including the first with D*, and all are equal to Css,max. These conditions are met when D/D* = 1-f.

The copyright of the quoted is hold by Trustees of Boston University. Permission has been granted for its use in this blog.

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