Guide to Good Prescribing - A Practical Manual
(1994; 115 pages) [French] [Spanish] View the PDF document
Table of Contents
View the documentAcknowledgments
View the documentWhy you need this book
Open this folder and view contentsPart 1: Overview
Open this folder and view contentsPart 2: Selecting your P(ersonal) drugs
Open this folder and view contentsPart 3: Treating your patients
Open this folder and view contentsPart 4: Keeping up-to-date
Close this folderAnnexes
Close this folderAnnex 1: Essentials of pharmacology in daily practice
View the documentIntroduction
Close this folderPharmacodynamics
View the documentThe Cp/response curve
Open this folder and view contentsPharmacokinetics
Open this folder and view contentsDrug treatment
Open this folder and view contentsSpecial features of the curve
View the documentAnnex 2: Essential references
Open this folder and view contentsAnnex 3: How to explain the use of some dosage forms
Open this folder and view contentsAnnex 4. The use of injections
View the documentBack Cover
 

Pharmacodynamics

The effects of a drug are usually presented in a dose-response curve. The effect of the drug is plotted on the Y-axis and the dose on the X-axis (Figure 10). The dose is usually plotted on a logarithmic scale. The higher the dose the stronger the effect, until the effect levels off to a maximum. The effect is usually expressed as a percentage of the maximum. The maximum effect of one drug may be more than that of another. Desired and side effects can both be plotted in dose-response curves.


Figure 10: Dose-response curve

The dose is usually expressed per kilogram body weight or per m2 body surface area. However, the most accurate way is to use the plasma concentration, because it excludes differences in absorption and elimination of the drug. In the following text the plasma concentration-response curve (Cp/response curve) is used.

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