Antiacetylcholine Drugs: Chemistry, Stereochemistry, and Pharmacology

Publisher Summary This chapter discusses the chemistry, stereochemistry, and pharmacology of antiacetylcholine drugs. Acetylcholine and certain other esters and ethers of choline have marked effects on the cardiovascular system with low doses causing reductions in blood pressure and higher doses reductions in heart rate. These effects are abolished by atropine but not influenced by section of the vagus and so are assumed to be peripheral in origin. Larger doses of acetylcholine given to atropinized animals cause increases in blood pressure. The actions of acetylcholine and related agonist drugs at the postganglionic parasympathetic endings are muscarinic, whereas agonist actions at autonomic ganglia and the skeletal neuromuscular junction are nicotinic. Similarly, there are antagonist drugs, which more or less specifically block the actions of acetylcholine at these different sites. Unless accurate and reproducible pharmacological testing procedures are chosen and evaluated thoroughly, attempts to interpret pharmacological results in terms of mechanism of drug action are of little value.