Compounds with Medicinal Properties

A drug, in the pharmacological sense used throughout this section, is any chemical that interacts with the body's biomolecules -- carbohydrates, lipids, proteins or nucleic acids -- and, through that interaction, produces a biological response. A medicine is a step further: it is a formulation that contains a drug as its active ingredient, chosen specifically because that drug's biological response is therapeutic and useful, together with additional chemicals that make the formulation suitable and practical to actually use as a medicine (for taste, stability, delivery and so on). Medicines are used across the full span of managing disease -- in diagnosis, in prevention, and in treatment. Because a drug is, chemically speaking, a foreign substance being introduced into the body, drugs commonly give rise to undesirable, adverse side effects alongside their intended therapeutic action, and managing this trade-off is a central concern of medicinal chemistry. Drug design -- the branch of medicinal chemistry devoted to synthesising new molecules with an improved biological response, ideally with fewer side effects -- is accordingly an active and important area of current research, and the chapter notes a growing trend within that research to draw on traditional medical knowledge, such as Ayurveda, and on natural materials more generally, as a starting point for discovering new drugs. A useful, closely related fact about how medicines reach the market: a company that develops a new drug typically holds a patent on it and sells it under it …