Treating Diseases Flashcards
What is the difference between a painkiller and an antibiotic
Painkillers help relieve symptom of infection but do not kill the pathogen that causes it
Antibiotics kill the pathogen that causes the disease
Give examples of painkillers
Rennie for indigestion Paracetamol Ibuprofen Neurogenic Cal poly Codeine Hydrocortisone
How do antibiotics work
1 Some antibiotics are bacterial - kill the bacteria eg penicillin - interfere with the formation of bacteria cell walls or content
2 Bacteriostatic - work by stopping bacteria multiply
Who founded antibiotics
Alexander Fleming 1881-1955
Studied bacteria
Noticed mould called penicillium growing as a ring around the cells
Something had killed the bacteria covering the jelly
He called the antibiotic substance penicillin
What are the problems with using antibiotics to rest infectious disease
1 They do not kill viruses so don’t work on viral infection
2 antibiotic resistance - bacteria deflect the antibiotic treatment
What must drugs need to be effective
Effective and safe
Must undergo extensive trials 12 years cost £1700 million
Egyptians used mouldy bread
1897 willow tree bark synthesised to make aspirin
Digitalis from foxgloves used to treat heart problems
Most drugs are synthesised by chemists in pharmaceutical in industry
What are the stages of drug development
1 discovery - identify chemicals by computer simulations
2 pre clinical - test on cell tissues and organs for toxicity
3 pre clinical test on animals - how it works in living organism
4 clinical phase 1 - healthy volunteers for side effects
5 clinical phase 2 - small group of patients to see if it works
6 clinical phase 3- large patient group to establish right dose
7 ongoing phase 4 - monitor in use after licence granted for long term effects and side effects
What are double blind trials
Some patients given the drug
Others given a placebo
Neither doctor nor patient knows who has been given drug or placebo
Why are double blind trials used
The placebo is used as it compares existing drug results with trial drug progress
Important that neither doctor nor patient knows because trial must be fair and without any bias in care or treatment
How does immunity work
Exposure to a microbe produces antibodies specific to that microbe - primary response
Lymphocytes and white blood cells that produce antibodies may stay in circulatory system (memory cells)
If same microbe attacks again lymphocytes and white blood cells produce appropriate antibodies to destroy microbe- secondary response
Microbe doesn’t have change to reproduce and release toxins
So they are immune to the microbe or disease
Why do we use vaccinations of immunisations
Some pathogens make you ill very quickly before body makes correct antibodies
Protect by immunisation
How does vaccination work
Small amount of inactive pathogen injected
Antigens in vaccine stimulate white blood cells to make antibodies
Antibodies destroy antigens without risk of getting the disease
Immune to future infection for that pathogen - white blood cells can now respond rapidly and make core t antibodies more quickly
What is herd immunity
Vaccinate a large part of population to reduce spread of disease
There are fewer individuals in population who can then be infected and spread disease to others
If no people vaccination -> infection spreads easily
Some vaccinations-> lots of people still infected
More vaccinations-> fewer people infected
Enough vaccinations may cause disease to disappear
But if number of vaccinations then fall herd immunity lost and disease may reappear
Examples of vaccinations
HPV MMR Tetanus Polio Meningitis
What are the different types of vaccination methods
1 Injecting modified live bacteria or virus eg TB, rubella
2 injecting parts of virus to act as antigens eg flu vaccination
3 injecting a modified toxin eg diphtheria
4 injecting dead bacteria or virus eg whooping cough
