I. DRUG INTERACTIONS
For example, metoclopramide and cisapride promote gastric emptying by increasing acetylcholine release from the vagus nerve. Atropine slows down gastric emptying by blocking muscarinic receptors.
Drugs that induce hepatic microsomal enzymes diminish the efficacy and duration of action of drugs metabolized by the cytochrome P450 enzyme system. Examples include phenobarbital, phenytoin, griseofulvin, phenylbutazone, rifampin, and chlorinated hydrocarbons (lindane and methoxychlor), which can induce cytochrome P450 enzymes.