Organic Chemistry

Librium

Valium

Ativan

A

drugis any ab-

sorbed substance

that changes or en-

hances a physical or psycho-

logical function in the body. A

drug can be a gas, a liquid, or a

solid and can have a simple structure or a complicated one. Drugs have been used by

humans for thousands of years to alleviate pain and illness. By trial and error, people

learned which herbs, berries, roots, and bark could be used for medicinal purposes.

The knowledge about natural medicines was passed down from generation to genera-

tion without any understanding of how the drugs actually worked. Those who dis-

pensed the drugs—medicine men, shamans, and witch doctors—were important

members of every civilization. However, the drugs available to them were just a small

fraction of the drugs available to us today.

Even at the beginning of the twentieth century, there were no drugs for the dozens of

functional, degenerative, neurological, and psychiatric disorders; no hormone thera-

pies; no vitamins; and—most significantly—no effective drug for the cure of any in-

fectious disease. Local anesthetics had just been discovered, and there were only two

analgesics to relieve major pain. One reason that families had many children was

because some of the children were bound to succumb to childhood diseases. Life spans

were generally short. In 1900, for example, the average life expectancy in the United

States was 46 years for a man and 48 years for a woman. In 1920, about 80 of every

100,000 children died before their fifteenth birthday, most as a result of infections in

their first year of life. Now there is a drug for treating almost every disease, and this is

reflected by current life expectancies: 74 years for a man and 79 years for a woman.

Now only about four of every 100,000 children die before the age of 15—mainly from

cancer, accidents, and inherited diseases.

The shelves of a typical modern pharmacy are stocked with almost 2000 prepara-

tions, most of which contain a single active ingredient, usually an organic compound.

These medicines can be swallowed, injected, inhaled, or absorbed through the skin. In

2001, more than 3.1 billion prescriptions were dispensed in the United States. The most

widely prescribed drugsare listed in Table 30.1 in order of the number of prescriptions

1204

30

The Organic Chemistry

of Drugs

Discovery and Design

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