Antibiotics, such as penicillin, kill bacteria inside the body; they do not work on viruses. Painkillers like paracetamol relieve symptoms but do not kill pathogens. Overuse of antibiotics has led to resistant strains such as MRSA, because resistant bacteria survive and reproduce. To slow this, doctors avoid prescribing antibiotics for viral infections and patients finish the full course.
New medicines are tested for toxicity, efficacy and dose. First they are tested in preclinical trials on cells, tissues and animals. Then clinical trials use healthy volunteers at low doses, then patients. In a double-blind trial, neither patients nor doctors know who receives the drug and who receives a placebo, which avoids bias. Results are checked by other scientists (peer review) before publication.
Worked example
Why won't an antibiotic help a cold?
- Colds are caused by viruses.
- Antibiotics kill bacteria, not viruses.
Answer:So the antibiotic would not help, and could encourage resistance.
Key words
- antibiotic
- a medicine that kills bacteria
- resistance
- bacteria no longer killed by an antibiotic
- placebo
- a dummy treatment with no drug
- double-blind
- neither patient nor doctor knows who gets the drug
New questions every time.
NGSS-referenced: HS-LS1-2