What Are Drugs and Where Do They Come From?

Define the terms “drugs,” “pharmacology,” “receptors” and “xenobiotics”

• Drug- A chemical substance that is given to prevent or cure disease or to enhance the mental or physical state of a human or animal. As the term "drugs" is often associated with illicit drugs, many people prefer to use the term "medicine," which only refers to drugs used to prevent or cure disease.
• Pharmacology- The study of how drugs work.
• Receptor- A molecule that a drug can bind to in order to produce a change in the body.
• Xenobiotic- A chemical that enters the human body. Includes not only drugs, but also other kinds of chemicals that might enter the body.

Appreciate the scope of pharmacology as a scientific discipline.

• What is Pharmacology?

Understand how 3 types of names are assigned to drugs.

The three main types of names are the chemical name, generic name, and brand name. See here for more information.

Show a basic awareness of 6 identifiable routes to finding new medicines.

“Bioprospecting”-Based Exploration

Some drugs are derived from useful substances in nature. For instance, penicillin comes from the Penicillum fungus.

Disease-Model Screening

Sometimes medications can be screened in animal models to give an indication if they might work in humans. An example of this is prontosil, a sulfonamide antibiotic.

“Me-Too” Drug Optimisation

Some drugs have been created by improving on previous drugs. For instance, captopril is an ACE inhibitor that can be taken orally- an improvement over earlier ACE inhibitors that could only be taken by injection.

Astute Clinical Observation

Sometimes drugs that were created for a different purpose might have useful unexpected effects. Sildenafil (Viagra) was not originally made to treat erectile dysfunction, but it was found to have "unexpected effects" in middle-aged males.

Rational Design

Rational drug design is basically the "gold standard" of drug discovery. Basically, chemists try and find a molecule that will fit a particular target. An example of a drug that was discovered this way is dorzolamide, a carbonic anhydrase inhibitor used to treat glaucoma (destruction of the optic nerve).

Irrational High-Throughput Discovery

Irrational high-throughput discovery makes use of our ability to test lots of chemicals simultaneously in vitro. One drug that has been found this way is sorafenib, which is primarily used to treat liver cancer.