What Is Pharmacology? Medicines, Drugs and Their History
8 minute read
What you will learn
- Define pharmacology
- Describe the main steps in the history of pharmacology
- Define drug and medicine
- State the differences between a drug and a medicine
- Explain why pharmacology matters to a pharmacy technician
- Match key discoveries with their discoverers
Key points
- Pharmacology is the science that studies drugs: their sources, actions, uses, fate in the body and harmful effects.
- People have used plants, minerals and animal products as medicines since the earliest times, including in traditional African medicine.
- Modern pharmacology grew from the isolation of pure drugs from plants in the 1800s and the development of synthetic drugs and antibiotics in the 1900s.
- A drug is any substance that changes how the body works. A medicine is a drug prepared and supplied to treat, prevent or diagnose disease.
- Not every drug is a medicine, because poisons and drugs of abuse are drugs too.
- Pharmacy technicians need pharmacology to dispense safely, spot errors and counsel patients.
What is pharmacology?
Pharmacology is the science that studies drugs. It asks:
- Where do drugs come from?
- What do they do to the body, and how?
- What does the body do to them?
- What are they used for?
- What harm can they cause?
The word comes from the Greek pharmakon (drug) and logos (study). Pharmacology is the base of the pharmacy profession. Every decision about a medicine, from storage to counselling, rests on it.
A short history
| Period | Development |
|---|---|
| Earliest times | People used plants, minerals and animal products to treat illness. Traditional medicine in Africa, Asia and elsewhere built up knowledge over centuries |
| About 1550 BC | The Egyptian Ebers Papyrus lists hundreds of remedies |
| About 400 BC | Hippocrates, the Greek physician, taught that illness has natural causes and should be treated with careful observation |
| 1st century AD | Dioscorides wrote a famous book on medicinal plants |
| 2nd century AD | Galen made preparations from plants, which are still called galenicals |
| 1500s | Paracelsus taught that the dose makes the poison: a substance can be a medicine in a small dose and a poison in a large one |
| 1796 | Edward Jenner made the first smallpox vaccine |
| 1804 | Friedrich Serturner isolated pure morphine from opium |
| 1847 | Rudolf Buchheim set up the first university department of pharmacology |
| 1909 | Paul Ehrlich introduced the idea of chemotherapy: drugs that kill germs without harming the patient |
| 1921 | Banting and Best discovered insulin |
| 1928 | Alexander Fleming noticed penicillin, and in the 1940s Florey and Chain made it into a useful medicine |
| 1900s onwards | Synthetic drugs, vaccines, antibiotics, hormones and, later, medicines made by biotechnology |
You do not need every date, but you should know the main names and what they did.
Drug and medicine
| Term | Meaning |
|---|---|
| Drug | Any substance that changes how the body works, whether helpful or harmful. This includes poisons and drugs of abuse |
| Medicine | A drug that has been prepared in a suitable form and quality and is supplied to treat, prevent or diagnose disease, or to help the body |
Differences between a drug and a medicine
| Drug | Medicine |
|---|---|
| Broad term for any substance that alters body function | A drug made ready for medical use |
| May be good or harmful | Made and supplied to help, with the risks known and controlled |
| Can be a raw or pure chemical | Made into a dosage form with the right strength and quality |
| Includes illegal and abused drugs | Supplied through lawful channels, with a label and directions |
| Not always safe to take | Safe when used as directed |
Many textbooks use the words loosely, and some treat the two terms as having the same meaning. In an examination, use the definitions in your textbook, and state the difference in your own words.
Why this matters for you
As a pharmacy technician you:
- dispense accurately, and notice when a dose, a combination or a medicine looks wrong;
- counsel patients on how to take medicines, what to expect, and what to avoid;
- store medicines properly, as you know what damages them;
- support the pharmacist, who makes the final clinical decisions;
- know the limits of your role, and refer what you cannot answer.
Pharmacology is also the largest part of the NPCE, so these lessons are the base for later ones.
Exam focus
- Define pharmacology, drug and medicine in one or two sentences each.
- State two differences between a drug and a medicine.
- Match discoveries with dates and names: Jenner, Serturner, Ehrlich, Fleming, Banting and Best.
- Common mistake: using 'drug' and 'medicine' as if they always meant the same thing.
Quick check
Test yourself before you move on. Pick an answer to see the explanation.
1.Pharmacology is best defined as the science that studies:
2.Which statement about 'drug' and 'medicine' is correct?
3.Which of these is a drug but is NOT used as a medicine?
4.Who is credited with developing the first smallpox vaccine in 1796?
5.Why does a pharmacy technician study pharmacology?