The conceptual process of drug discovery is one that is often the result of an identified need in a defined disease area. This need represents a mandate from the marketing department of a phar maceutical company or a breakthrough at the research level that has agreed applicability in response to a valid therapeutic demand. Although the intelligent design and development of new thera peutic entities, as evidenced by Sir James Black's H -receptor an 2 tagonist cimetidine (Tagamet), is intellectually satisfying, many novel drugs arise from serendipity, from the chance observation of the research...