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Developing Drugs
Developing Drugs Revision
Developing Drugs
Drugs are usually based on chemicals found in plants and microorganisms. They are developed by scientists and go through a series of extensive testing to determine their efficacy, dose and whether they are safe for public use.
Origins of Drugs
Traditionally drugs were extracted from various plants and microorganisms.
In more recent times, drugs are developed and synthesised by chemists in laboratories. However, the drugs made are often based on the original chemicals from plants and microorganisms:
- Alexander Fleming discovered the first antibiotic substance from penicillium mould. He named it penicillin after its origin.
- Aspirin is a painkiller derived from willow.
- Digitalis is a heart drug that originates from fox gloves.
Preclinical Testing
Before being given to humans, medical drugs must be thoroughly tested to ensure the drug is effective and safe to use and also to determine the best dosage. The investigations then get peer reviewed to check their accuracy before being published in journals to prevent false claims.
The first stages of the testing do not involve giving the drug to humans and are called preclinical trials:
- To check for efficacy and toxicity, the drug is tested using computer models or is given to human cells cultured in a lab.
- To test for side effects and to determine a rough dosage for humans, the drug is given to animals.
Clinical Testing
After passing the preclinical testing, the drugs can be tested on actual people in clinical trials.
Healthy people are tested first at low doses to ensure the drug is safe and has no major side effects in humans. Then the dose is gradually increased to help determine the optimum dose.
Once it is clear that the drug is safe for healthy humans, it is tested on ill patients with the disease to determine if it actually works and to determine an accurate dosage. Double blind trials are used to do this:
- Patients are split randomly into two groups.
- One group is given the drug and the other is given a placebo (looks the same as the drug but has no effect).
- The effects of the treatments are observed.
- Neither the patients or doctors know who has been given which treatment to avoid any bias.
Only after it has passed this testing is it safe to be used to treat the illness.
Developing Drugs Example Questions
Question 1: Name a medical drug and its plant origin.
[1 mark]
Any one from:
Aspirin comes from willow trees.
Digitalis originates from fox gloves.
Question 2: Why is peer reviewing important?
[1 mark]
Ensures published research is accurate.
Question 3: Describe what happens in a double blind trial for a drug and state they are important.
[3 marks]
- Patients split into 2 groups– one is given the drug, the other is given a placebo.
- The doctors and patients do not know who has which treatment.
- Avoids bias.
Developing Drugs Worksheet and Example Questions
Drug Discovery Questions
GCSEOfficial MME
Drug Development Questions
GCSEOfficial MME
