Pharmacology

Reception Theory

A drug receptor is a specialized target macromolecule that binds a drug and mediates its pharmacological action.

These receptors may be enzymes, nucleic acids, or specialized membrane-bound proteins.

The formation of the drug-receptor complex leads to a biological response.

The magnitude of the response is proportional to the number of drug-receptor complexes.

A common way to present the relationship between the drug concentration and the biological response is with a concentration- (or dose-) response curve. Because the biological effect is more closely related to the plasma concentration than to the dose, this will be shown.

FIGURE 2–1

In A, the concentration-response curve for a full agonist is presented. The drug can produce a maximal effect. In B, the concentration-response curve for a partial agonist is also shown. In this case, the partial agonist is able to produce only 60% of the maximal response.

Two graphs show concentration-response curves and compare a partial agonist with a full agonist.

Agonists

Reception Theory

FIGURE 2–1

Pharmacological Principles