Intro To Healthcare Science

Front 1

What does ADME stand for?

Back 1

Absorption

Distribution

Metabolism

Excretion

Front 2

What is the difference between pharmacodynamics and pharmacokinetics?

Back 2

Pharmacodynamics: study of the effects of drugs on the body

Pharmacokinetics: study of the effect of the body on a drug

Front 3

What is first pass metabolism and where does it happen?

Back 3

Where drugs are metabolised (fully or partially) before they reach systemic circulation

Occurs in the lungs, gastrointestinal tract, or liver

Front 4

What is volume of distribution and how do you calculate it?

Back 4

Theoretical measurement of the extent to which a drug moves into the tissues - high Vd means drug moves into tissue quickly, low Vd means drug stays in blood longer

VD = total conc of drug in body / conc of drug in plasma

Front 5

Describe the 3 main types of phase 1 metabolism and what carries them out?

Back 5

1. Hydrolysis - water used to break a bond

2. Oxidation - electrons removed to become more positive

3. Reduction - electrons added to become more negative

Cytochrome P450 enzymes (CYP) in the liver

Front 6

How do you calculate drug clearance?

Back 6

Clearance = (Cu X Vu) / Cp

Cp: drug conc in plasma

Cu: drug conc in urine

Vu: rate of urine production

Front 7

What is the difference between first and zero order kinetics?

Back 7

First order kinetics: half life is a constant value as a drug is being excreted

Zero order kinetics: enzyme required to metabolise a drug for excretion is saturated so excretion rate is linear until it is no longer saturated, half life depends on drug conc

Front 8

What is the prevention paradox?

Back 8

A preventative measure that brings large benefits to the community offers little to each participating individual

Front 9

How do you calculate sensitivity?

Back 9

True positives / all disease positives X 100

All positives is true positives + false negatives

Front 10

How do you calculate specificity?

Back 10

True negatives / all disease negatives X 100

All disease negatives is true negatives + false positives

Front 11

How do you calculate PPV?

Back 11

True positives / all test positives x 100

All test positives is true positives + false positives

Front 12

How do you calculate NPV?

Back 12

True negatives / all test negatives X 100

All test negatives is true negatives + false negatives

Front 13

What is incidence and how do you calculate it?

Back 13

The number of instances of illness commencing, or of persons falling ill, during a given period

Incidence rate = number of new cases / average population

Front 14

What is prevalence and how do you calculate it's rate?

Back 14

(Total number of individuals with an attribute or disease / population at risk) x duration

Point prevalence: at a given time

Period prevalence: over a given period

Front 15

How do you calculate absolute, relative, and attributable risk?

Back 15

Absolute risk = no. of events / total population at risk x 100%

Relative risk = risk in group 1 / risk in group 2

Attributable risk (AKA risk difference) = risk in group 1 - risk in group 2

Front 16

What is bioavailability and how is it calculated?

Back 16

The % or fraction of administered dose that reaches systemic circulation (F)

F x dose = amount of drug absorbed

Front 17

What are the therapeutic index and therapeutic window?

Back 17

Therapeutic index: the ratio between lethal dose and therapeutic dose

Therapeutic window: concentration range where drug is therapeutic without being toxic

Front 18

Order the following in terms of speed of drug absorption: injection, oral, inhaled

Back 18

Inhaled - injection - oral

Front 19

What are the 2 main ways drugs are excreted?

Back 19

1. Kidneys - drug enters nephrons, moves through collecting duct into urine

2. Hepato-billiary system - if it is insoluble in water, the liver excretes drug into bile, removed in faeces

Front 20

When would you use incidence and prevalence?

Back 20

Incidence: assessing acute conditions

Prevalence: monitoring conditions over time

Front 21

Describe the 5 types of epidemiological studies

Back 21

1. Cohort studies - people with and without exposure of interest followed over time (observational/analytical)

2. Case-control studies - outcome has already occured, data gathered (observational/analytical)

3. Ecological studies - multiple populations compared (descriptive)

4. Cross-sectional studies - association between exposure and outcome at a specific time point (descriptive)

5. Randomised-control trials (interventional)

Front 22

Which databases are useful for public health?

Back 22

Medline, FRANTEXT, Embase, ABELL, Scopus

Front 23

What do you calculate in a case control study?

Back 23

Odds ratio - chances of getting the disease

Front 24

How do you calculate odds ratio and what does an odds ratio of 1 mean?

Back 24

No. of events / no. of non-events

1 = exposure does not effect the chances of an outcome occuring

Front 25

What is confounding?

Back 25

When an observed association is due to the effects of differences between study groups that alters their risk of developing the outcome of interest

Eg measure alcohol consumption and depression, but smoking is a confounding factor

Front 26

What are the infectious diseases in pregnancy screening?

Back 26

Hep B, syphilis, HIV

Front 27

What vaccines are available to all children?

Back 27

Diphtheria, measles, pertussis

Front 28

Why don't all children have the same vaccines?

Back 28

They are given based on evidence, some areas have low incidence rates, so if there's no history of the disease in your family, you won't be given the vaccine

Front 29

Who provides expert advice on vaccines in England?

Back 29

JCVI

Front 30

Does every child have the BCG vaccine and how is it administered?

Back 30

It is risk based so not everyone has it, given intradermally

Front 31

Describe the bases in DNA

Back 31

A + G are purines, double cyclical ring

C + T are pyrimidines, single cyclical ring

Front 32

How many stop and start codons are there?

Back 32

6 stop, 1 start

Front 33

What is the most common cause of cystic fibrosis?

Back 33

Codon deletion

Front 34

What is pharmacogenomics and why is it useful?

Back 34

Study of how genes effects a person's response to drugs

Avoid adverse drug reactions, tailor treatment to genotype

Front 35

What is MTRNR1?

Back 35

A mitochondrial DNA change that can cause deafness if a certain antibiotic is given to babies - newborns are screened using POCT

Front 36

What is a half life?

Back 36

Time taken for concentration of drug in the blood to decrease by half

Front 37

What is steady state?

Back 37

Where the rate of drug intake = rate of drug excretion

Usually this the therapeutic level, approx 5 half lives

Front 38

What is phase 2 metabolism?

Back 38

Conjugation of a group to make it more water soluble/less chemically active

Eg glutathione, methyl or acetyl

Front 39

Describe the metabolism of paracetamol

Back 39

Phase 1: NAPQI metabolite produced, can cause liver injury

Phase 2: conjugation with glutathione to make it non-toxic

Front 40

What are pro-drugs?

Back 40

Drugs that are not active until metabolised - first pass metabolism doesn't reduce the concentration available

Front 41

How can liver and kidney functioning be measured?

Back 41

Liver: bilirubin, ALP, albumin

Kidney: creatinine, eGFP

Front 42

What are pharmacokinetic drug interactions and what can they effect?

Back 42

Where the handling of one drug by the body effects the handling of another

Effect protein binding (eg warfarin and aspirin bind to same proteins), absorption, metabolism and secretion

Front 43

What are pharmacodynamic drug interactions?

Back 43

Where the effect of one drug is altered by another at the site of action - additive (eg 2 drowsy drugs = super drowsy) or antagonistic

Front 44

Is the rate of drug absorption affected by drug interactions?

Back 44

Rarely, only if one drug speeds or slows the GI tract

Front 45

Summarise CT scans

Back 45

1. 3D image made by rotating round patient

2. Density is normalised to water (Houndsfield units)

3. Measures attenuation (absorbance of x-rays means less is transmitted through)

4. Use of x-rays means scan dose must be justified

Front 46

What are the clinical uses for CT scans?

Back 46

1. Oncology - diagnosis, treatment planning and monitoring

2. Angiography using iodine to see blood flow over time, also can do 4D

3. Cardiology - beta blocker to slow heart for imaging, look for calcifications

Front 47

Summarise PET scans

Back 47

1. Measures metabolic activity (brain, brown fat and kidney light up)

2. Tracers given to patient (eg 18F-FDG), taken up at sites of metabolic activity

3. Positron from PET meets electron and annihilates tracer, emitting energy (y-rays)

4. Needs CT scan for anatomy

5. Lie still for 30 mins

Front 48

What are the clinical uses for PET scans?

Back 48

1. Oncology - very metabolically active, can find edges of tumours

2. Neurology - lower activity in Alzheimer's

3. Pharmacokinetics - monitor rate of drug uptake

4. Cardiology - imagine heart disease + stress testing

Front 49

Summarise ultrasound

Back 49

1. Sound is emitted by piezoelectric crystals oscillating (vibrating) (2-15 MHz) and reflected back

2. Bone is so dense you can't see past it

3. Uses longitudinal wave

4. Sound travels faster in tissue than air

5. Doppler effect can measure speed of blood flow

6. Sound can scattered or be distorted by surfaces

Front 50

Summarise MRI

Back 50

1. Aligns protons in body, use radiowaves to shift 90° then return - emit radiowaves on relaxation

2. T1 weighting = dark fluid

3. T2 weighting = bright fluid

4. Can add contrast agent for enhanced MRI

5. MAGNETIC (B0)

Front 51

What are the clinical uses for MRI?

Back 51

1. Functional MRI - brain activity

2. Cardiology - workings of the heart

3. Angiography - use gadlineum contrast

4. Oncology - contrast enhance MRI helps

Front 52

Describe an MRI machine

Back 52

Superconducting magnet cooled with liquid helium, gradient coils make protons soon at specific frequencies, body coil sends radiowaves into patient receive coil picks up radiowaves from patient and converts to image

Front 53

Which study designs can you use in an outbreak scenario?

Back 53

1. Case control study

2. Cohort study

Front 54

How can drugs impact metabolism of another drug?

Back 54

1. Drug may be P450 inducer, increasing metabolism of second drug

2. Drug may be P450 inhibitor, slowing metabolism of second drug

Front 55

What is an autosome and how many are there in each cell?

Back 55

A chromosome that isn't a sex chromosome (allosome) - 44 autosomes, 2 allosomes

Front 56

How is the 3D image in CT scans created?

Back 56

Reconstruct the attenuation of each element (voxel) by filtered back projection

Front 57

How do you calibrate CT for dose calculations?

Back 57

Phantoms: items of known density which are scanned to produce a curve

Front 58

What is genomics?

Back 58

Study of an entire organisms genes and non-coding DNA