# Pharmacology

**Pharmacology** is the study of how medicine and other things have an effect on living organisms and change how they function. Pharmacology could also be defined as the study of how medicine actually works.

The first pharmacology department in the world was set up in the University of Tartu by Rudolf Buchheim in 1847.

Pharmacology is not exactly the same as pharmacy, and a pharmacologist is not exactly the same as a pharmacist. A pharmacologist is a scientist who studies how medicine actually works, and usually works in a science lab. A pharmacist is a health care provider who usually works at a pharmacy. However, there is quite a bit of overlap between these two fields. A pharmacist could be considered a type of pharmacologist. Pharmacists do take many classes in pharmacology and law.

Drugs which can be used as medicine are called pharmaceuticals. Pharmacology includes how drugs are made, how they interact with living organisms, what effects (good or bad) they could have, how they can be used as medicines, and if they can be used to prevent illness. They might also study the side effect profile of a drug and find out what adverse effects they can cause, either on human volunteers or animals such as mice. A person who works in the study of pharmacology is called a pharmacologist. Pharmacologists work in a team with biochemists, geneticists, microbiologists, toxicologists and pharmacists to run clinical tests on how drugs work.

## History

People have used drugs since very early times. One of the oldest drugs is opium, which comes from the poppy plant. It was used before 1100 BCE to reduce pain and help people sleep. Hippocrates vouched for the (sparing) use of opium in to treat pain and in gynecological procedures. He also wrote about its use in some texts.

During the Middle Ages, the study of medicine and drugs slowly improved. Many medicines came from plants. A famous doctor named Avicenna wrote a medical book called The Canon of Medicine. It explained how drugs should be prepared and used. Other European doctors also wrote books about medicines.

Early medicine focused on herbs and natural substances. Doctors collected information about drugs in books called pharmacopoeias. These drugs were not pure. They often contained many different substances mixed together.

Different cultures developed their own kinds of medicine. Examples include Chinese medicine, Tibetan medicine, Korean medicine, and Mongolian medicine. Some of these traditions are still used today, but many ideas are not supported by modern science.

In the 1600s, an English doctor named Nicholas Culpeper translated medical books into English. He described plants and explained which illnesses they could treat. In the 1700s, William Withering helped make drug study more scientific.

In the 1800s, pharmacology became a modern science. Scientists learned how to separate pure drugs, such as morphine, quinine, and digitalis. They also began to understand how drugs work inside the body.

The first university department for pharmacology was opened in 1847 at the University of Tartu. In England, the first pharmacology department opened in 1905 at University College London.

Today, pharmacology uses modern science such as biology, chemistry, and genetics. Scientists study how drugs affect cells and organs. This research helps create better medicines, improve medical tests, and develop personalized medicine.

## Uses of pharmacology

The development of drugs is very important to medicine, but it also has strong economical and political uses. To protect people and prevent abuse, some countries try to control the way in which drugs are made, sold, and administered.

## Scientific background

To study chemicals, a person needs to know a lot about what will be affected if it is ingested (taken into the body). As more people know about cell biology and biochemistry, the field of pharmacology has changed as well. It is now possible to design chemicals that do specific things.

A chemical can have different properties. Pharmacokinetics describes the effect the body will have on the chemical, and pharmacodynamics describes the chemical's effect on the body (desired or toxic).

When a pharmacologist is talking about pharmacokinetic properties of a chemical, they are interested in four things: ADME.

* **Absorption** - How is the medication absorbed (through the skin, the intestine, the mouth)?
* **Distribution** - How does it spread through the organism?
* **Metabolism** - Is the medication converted chemically inside the body, and into what. Are these new substances active? Could they be toxic?
* **Excretion** - How does the organism get rid of the chemical (through the bile, urine, breath, skin)?

Medication is said to have a narrow or wide therapeutic index. This describes the ratio of desired effect to toxic effect. A medicine with a narrow therapeutic index (close to one) only does what people want it to do when the amount given is enough to put the organism in danger. A medicine with a wide therapeutic index (greater than five) does what people want it to do and does not necessarily put the organism in danger. Medication with a narrow margin are more difficult to dose and give to a person, and may require therapeutic drug monitoring (examples are warfarin, some antiepileptics, aminoglycoside antibiotics). Most anti-cancer drugs have a narrow therapeutic margin and toxic side effects are almost always encountered at doses needed to kill tumours.

## Drugs as medicine

Drugs that are given to people to help cure them of a medical condition or help reduce the symptoms are often licensed. They can be divided into three groups: over-the-counter, where anybody can buy the drug from a shop; prescription-only medicine, where a doctor has to say that a person is allowed to take a drug; and in some countries, pharmacy medicines, where only a registered pharmacy can sell a drug. Most over-the-counter medication will not hurt a person if they take a bit more than they are meant to. Medications are often produced by pharmaceutical companies and are often patented. Drugs that are not patented, or where the patent has expired, are called generic drugs.

## Market

Early stage drug research is often done by small companies, start-ups, that later sell out to the big pharmaceutical companies. The patent lasts for up to 20 years. After that other companies can copy the invention.

The American market was worth more than $600 billion in 2022, almost half the global total. Americans pay three times as much for branded drugs as the OECD average. American research and development spending was nearly two-thirds of the OECD total. The 2022 Inflation Reduction Act lets Medicare bargain directly with drugmakers. It plans to seek cuts of 25% in some drugs. Private health insurers may do the same.

## Related pages

* Pharmacoepidemiology
* Pharmacokinetics
* Pharmacotheraphy