3.1.9: Discovery and development of drugs
Not started yet — this one needs some love.
Traditional drug sources:
Digitalis (heart drug): from foxgloves.
Aspirin (painkiller): from willow.
Penicillin (antibiotic): discovered by Alexander Fleming from the Penicillium mould.
Most new drugs are synthesised by chemists (though may start from a plant chemical).
Testing new drugs — three criteria: toxicity (is it safe?), efficacy (does it work?), dose (how much to give?).
Preclinical testing: in laboratory using cells, tissues and live animals; checks for toxicity.
Clinical trials:
Stage 1: very low doses given to healthy volunteers to check safety.
Stage 2: given to patients to check efficacy and find optimum dose.
Double-blind trial: some patients receive a placebo (inactive substance); neither doctors nor patients know who has the real drug.
Results published only after peer review (scrutiny by other scientists).
Common exam mistakes
Aspirin comes from willow (not foxgloves); digitalis comes from foxgloves (not willow) — these are frequently swapped.
Toxicity and side effects are essentially the same thing — cannot be counted as two separate points.
Efficacy = effectiveness — do NOT say 'efficiency', which has a different meaning.
In double-blind trials, neither the doctor NOR the patient knows who receives the real drug — both are 'blind'.
Peer review is the checking of results by other independent scientists before publication — not just having the trial repeated.