Chapter 21: Histamine, Bradykinin, and Their Antagonists

INTRODUCTION

This chapter will be most useful after having a basic understanding of the material in Chapter 32, Histamine, Bradykinin, and Their Antagonists in Goodman & Gilman’s The Pharmacological Basis of Therapeutics, 12th Edition. In addition to the material presented here, the 12th Edition contains:

• Table 32-1 Characteristics of Histamine Receptors, which shows the biochemical properties, tissue distribution, and representative agonists and antagonists of the 4 histamine receptors (H₁, H₂, H₃, and H₄)

• Table 32-2 Preparations and Dosage of Representative H₁-Receptor Antagonists

• The molecular structures of histamine and drugs that are agonists and antagonists of the various histamine receptors

LEARNING OBJECTIVES

• Understand the role of histamine and bradykinin in different physiological and pathophysiological processes.

• Understand the mechanisms of action of drugs that act as antagonists of the H₁ receptor.

• Know the therapeutic utility of H₁-receptor antagonists, alone and in combination with other agents.

• Know the important adverse effects of H₁-receptor antagonists, and the difference between first- and second-generation H₁ antihistamines with regard to adverse effects.