Chapter 1: Pharmacokinetics

Overview Pharmacokinetics refers to what the body does to a drug, whereas pharmacodynamics (see Chapter 2) describes what the drug does to the body. Once administered through one of several available routes, four pharmacokinetic properties determine the speed of onset of drug action, the intensity of the drug’s effect, and the duration of drug action […]

Chapter 2: Drug–Receptor Interactions and Pharmacodynamics

Overview Pharmacodynamics describes the actions of a drug on the body and the influence of drug concentrations on the magnitude of the response. Most drugs exert their effects, both beneficial and harmful, by interacting with receptors (that is, specialized target macromolecules) present on the cell surface or within the cell. The drug–receptor complex initiates alterations […]

Chapter 3: The Autonomic Nervous System

Overview The autonomic nervous system (ANS), along with the endocrine system, coordinates the regulation and integration of bodily functions. The endocrine system sends signals to target tissues by varying the levels of blood-borne hormones. In contrast, the nervous system exerts its influence by the rapid transmission of electrical impulses over nerve fibers that terminate at […]

Chapter 4: Cholinergic Agonists

Overview Drugs affecting the autonomic nervous system (ANS) are divided into two groups according to the type of neuron involved in their mechanism of action. The cholinergic drugs, which are described in this and the following chapter, act on receptors that are activated by acetylcholine (ACh), whereas the adrenergic drugs (discussed in Chapters 6 and […]

Chapter 5: Cholinergic Antagonists

Overview The cholinergic antagonists (also called cholinergic blockers, parasympatholytics, or anticholinergic drugs) bind to cholinoceptors, but they do not trigger the usual receptor-mediated intracellular effects. The most useful of these agents selectively block muscarinic receptors of the parasympathetic nerves. The effects of parasympathetic innervation are, thus, interrupted, and the actions of sympathetic stimulation are left […]

Chapter 6: Adrenergic Agonists

Overview The adrenergic drugs affect receptors that are stimulated by norepinephrine or epinephrine. Some adrenergic drugs act directly on the adrenergic receptor (adrenoceptor) by activating it and are said to be sympathomimetic. Others, which will be dealt with in Chapter 7, block the action of the neurotransmitters at the receptors (sympatholytics), whereas still other drugs […]

Chapter 7: Adrenergic Antagonists

Overview The adrenergic antagonists (also called blockers or sympatholytic agents) bind to adrenoceptors but do not trigger the usual receptor-mediated intracellular effects. These drugs act by either reversibly or irreversibly attaching to the receptor, thus preventing its activation by endogenous catecholamines. Like the agonists, the adrenergic antagonists are classified according to their relative affinities for […]

Chapter 8: Neurodegenerative Diseases

Overview Most drugs that affect the central nervous system (CNS) act by altering some step in the neurotransmission process. Drugs affecting the CNS may act presynaptically by influencing the production, storage, release, or termination of action of neurotransmitters. Other agents may activate or block postsynaptic receptors. This chapter provides an overview of the CNS, with […]

Chapter 9: Anxiolytic and Hypnotic Drugs

Overview Anxiety is an unpleasant state of tension, apprehension, or uneasiness (a fear that seems to arise from a unknown source). Disorders involving anxiety are the most common mental disturbances. The physical symptoms of severe anxiety are similar to those of fear (such as tachycardia, sweating, trembling, and palpitations) and involve sympathetic activation. Episodes of […]

Chapter 10: CNS Stimulants

Overview This chapter describes two groups of drugs that act primarily to stimulate the central nervous system (CNS). The first group, the psychomotor stimulants, cause excitement and euphoria, decrease feelings of fatigue, and increase motor activity. The second group, the hallucinogens, or psychotomimetic drugs, produce profound changes in thought patterns and mood, with little effect […]