DISCOVERING DRUGS Flashcards
(19 cards)
How were drugs initially discovered and extracted?
drugs initially discovered and extracted from plants and microorganisms
How can plants be used to treat symptoms of human diseases?
the chemicals that plants use to kill pests and pathogens can be used to treat symptoms of human diseases
Drugs that were initially extracted from plants and microorganisms:
-heart drug digitalis originates from foxgloves
-painkiller aspirin originates from willow
-penicillin was discovered by Alexander Fleming from the Penicillium mould
-Alexander Fleming was growing bacteria on plates
-he found mould (Penicillium mould) on his culture plates, with clear rings around the mould indicating there was no longer any bacteria there
-he found that the mould was producing a substance called penicillin which killed bacteria
How are new drugs developed today?
-new drugs mainly synthesised by chemists in the pharmaceutical industry
-need to be tested for toxicity, efficacy (how well they carry out their role) and dose using preclinical testing and clinical trials
What are new drugs extensively tested for?
new drugs extensively tested for toxicity, efficacy and dose
Placebo:
A substance designed to be indistinguishable from a drug being tested but has no actual effect on the patient
Placebo effect:
when a patient is given a placebo causing them to have the expectation that they’re symptoms will reduce - optimistic mindset may cause symptoms to reduce
Biased:
to feel/show inclination or prejudice for against someone/something
Risks of taking part in a drug trial:
-permanent effects e.g. permanently
-handicapped
-brain damage
-organ failure
-could be addictive
-death
What are the phases of drug testing and development?
1)Discovery and development
2)Preclinical testing
3)clinical testing
4)FDA Review
5)FDA Post-Market Safety and Monitory
What happens in the discovery and development phase of drug testing?
-Research for new drug begins in laboratory
-Synthetic chemicals:
chemists produce a wide range of new chemicals every yr
-many screened for useful medical effects
-sometimes chemists use computer models to design a molecule which should cure an illness
-then they try to make it in lab to se if it works as predicted (preclinical testing)
What happened in the preclinical testing phase of drug testing and development?
-uses cell cultures or body parts (in vitro screening) tested for toxicity, efficacy (how well they carry out their role) and dosage
-uses cells, tissues and live animals
What happens in animal testing (part of preclinical testing)?
-the few chemicals that pass in vitro screening move onto whole animal testing
-scientists think drug is safe but need to check on living body
-at this stage scientists learn how drug works in a living body
Advantages of animal testing:
-animal testing has helped to develop vaccines against diseases like rabies, polio, measles, mumps, rubella and TB.
-scientists claim there are no differences in lab animals and humans that cannot be factored into testing
-antibiotics, HIV drugs, insulin and cancer treatments rely on animal tests - other testing methods aren’t advanced enough
-operations on animals helped to develop organ transplant and open heart surgery techniques
Disadvantages of animal testing:
-different to a human’s
-animals are still used in test items like cleaning products which benefit mankind less than medicines or surgery
-successful alternatives include test tube studies on human tissue cultures statistics and computer models
-stress that animals endure in labs can effect experiments making the results meaningless
What happens in clinical testing (Phase I - Human Trials: Testing on Volunteers)?
-Phase I trials test safety and dosage in 20–100 healthy volunteers.
-Focus on side effects, toxicities, and how the body processes the drug (ADME).
-Increasing doses are given under close monitoring in a controlled setting.
-Determines if the drug is safe enough to move to Phase II (testing effectiveness).
What happens in clinical testing (Phase II - Human Trials: Testing on Patients)?
-Phase II trials test the drug’s effectiveness and further assess safety.
-Involves 100–300 patients with the disease or condition.
-Determines the optimal dose and gathers data on side effects.
-Researchers compare to placebo or standard treatment in some trials.
What happens in clinical testing (Phase III - Human Trials: Final Tests and Linking)?
-Phase III trials involve 1,000–3,000 patients with the disease.
-Test effectiveness, side effects, and comparison to current treatments.
-Usually randomized and double-blind to reduce bias.
-Gather final data for approval by regulatory bodies (like FDA, EMA).
What happens in clinical testing (Phase IV - Human Trials:Post-Market Monitoring)?
-Phase IV trials happen after the drug is approved and on the market.
-Involve long-term monitoring of effectiveness and rare side effects.
-Help find new uses for the drug and ensure continued safety.
-Involves large patient populations in real-world settings.
