Principles of pharmacotherapy: I. Pharmacodynamics.

This paper and the ensuing series present the principles guiding and affecting the ability of drugs to produce therapeutic benefit or untoward harm. The principles of pharmacodynamics and pharmacokinetics, the physiologic basis of adverse drug reactions and suitable antidotal therapy, and the biologic basis of drug allergy, drug-drug interactions, pharmacogenetics, teratology and hematologic reactions to chemicals are explored. These principles serve to guide those administering and using drugs to attain the maximum benefit and least attendant harm from their use. Such is the goal of rational therapeutics.