Discovery and Development of Drugs
Discovery of Drugs:
Many of today's medicines have their roots in natural remedies.
- ASPIRIN: derived from WILLOW BARK, is used as a PAINKILLER and to LOWER FEVER.
- PENICILLIN: comes from MOULD, and is used as an ANTIBIOTIC.
- DIGITALIS: Comes from FOXGLOVES, is used to treat HEART CONDITIONS.
Development of Drugs
The journey from the lab to the pharmacy shelf is a rigorous one for every new drug. Understanding this process is crucial for anyone interested in how medicines are safely brought to the market.
PRECLINICAL TRIALS (Cells, Tissues and Animals)
Stage 1:
- Drugs first undergo tests on HUMAN CELLS and TISSUES in the laboratory.
- Tests on whole or multiple body systems require the use of whole ANIMALS due to their complex circulatory systems.
Stage 2:
- The drug is tested on ANIMALS.
- The drug is tested for EFFICACY (how well it works), TOXICITY (potential harm) and DOSAGE (the concentration and how often the drug needs to be taken) using LIVE ANIMALS.
- In Britain, law requires testing on two different LIVE MAMMALS to ensure the drug's safety.
CLINICAL TRIALS (Humans)
Stage 3:
HEALTHY VOLUNTEERS are first to receive the drug to check for SIDE EFFECTS at low doses.
The dose is gradually INCREASED and tested until an OPTIMUM DOSE is found.
Stage 4:
Next, the drug is administered to PATIENTS in two groups:
- One group receives the NEW DRUG.
- The other group gets a PLACEBO (a substance that looks like a drug but doesn't do anything).
Trials are BLIND so the patient DOESN'T KNOW whether they are taking the real drug or the placebo. This prevents the PLACEBO EFFECT where the patient expects the drug is working so is subconsciously influenced.
Some trials are DOUBLE BLIND which means neither the patient nor the monitoring doctors know who received the actual drug or the placebo. This stops the doctors from being subconsciously influenced when analysing the results.
Finally PEER REVIEW of the results is conducted by other scientists to ensure the VALIDITY and RELIABILITY of the trial outcomes before publication.