ABSTRACT
The study of the way drugs work is called pharmacodynamics. Understanding drug activity is important for both the prescribing and the delivery of drug treatment, and for making sense of side-effects.
Neuropharmacology (dealing with the drugs affecting the nervous system) involves two basic drug actions, the agonist and the antagonist (Figure 6.1). Agonist drugs bind to receptors and activate the receptor in a manner similar to that of the natural ligand (the neurotransmitter), and in
Pharmacodynamics
this way the drug enhances the neurotransmitter activity. Antagonist drugs also bind to receptors but do not activate them. Instead, they block the receptor, thus preventing the binding of the natural ligand and the stimulation of the receptor. Antagonists are often called blockers as an indication of their role in preventing receptor activation.
