Emphasizing the molecular action of drugs, this text incorporates recent findings from biochemical pharmacology along with the latest insights into the interactions of drugs with their receptors. It is organized by targets of drug action--endogenous messengers and their receptors, membranes, enzymes, and DNA, among others--and covers all drug groups and their therapeutic applications. This new edition has been thoroughly revised to provide expanded coverage of co-transmitters and neurohormones as well as adenosine receptors and calcium channel blockers. The chapter on drug distribution and metabolism has been extended, and the final chapter on principles of drug design outlines new methods, such as numerical techniques and computer graphics. Other new topics include atrial natriuretic factors, antiarrhythmic drugs, and DNA topoisomerase inhibitory mechanism of antitumor and antibacterial agents. The text is illustrated with hundreds of formulas and tables, and the index inclu.