# A student is testing a new drug to treat a bacterial infection. Before the drug can be given to patients, it must go through several stages of testing. Describe the stages of drug testing that take place before a drug is approved for use in patients, and explain why each stage is necessary.

> Eduqas A-Level Biology — 3.4 Population size and ecosystems · Describe · 5 marks

> Scientists developing a new antibiotic must follow a strict testing process to ensure the drug is safe and effective before it is used to treat patients.

## Mark scheme (5 marks)

1. Preclinical testing is carried out first, using cells, tissues and/or live animals in a laboratory
2. Preclinical testing is necessary to find out whether the drug is toxic / causes harmful side effects before it is given to humans
3. Clinical testing follows, initially on healthy human volunteers
4. A placebo is used in clinical trials so that results can be compared / to rule out the placebo effect
5. Clinical testing on patients with the disease is carried out to check the drug is effective and to determine the optimum / safe dose

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-student-is-testing-a-new-a8da7895) · Published by Druglandscape Ltd.