Class Test (all lectures😎) Flashcards
What other conditions can be caused from hypertension?
ischemic heart disease
stroke
heart failure
chronic renal failure
what other conditions can be caused from atrial fibrillation
heart attack
stroke
what is atrial fibrillation
irregular and abnormally fast heart beat
what other conditions can be caused from ischemic heart disease or coronary artery disease
heart failure
stroke
what other conditions can occur from diabetees
ischemic heart disease
stroke
what other conditions can occur from heart failure
hyperthyroidism
COPD
what diseases are involved in Ischemic heart disease/ coronary artery disease
angina
myocardial infarction (heart attack)
sudden cardiac death
How does mortality occur from stroke?
- immediate death from thromboembolic event
or - later death due to complications associated with loss of swallowing reflex (aspiration pneumonia)
what is the most common type of stroke
ischaemic
what is an ischemic stroke
occur as a result of an obstruction within a blood vessel supplying blood to the brain
OBSTRUCTION
weither thrombotic or embolic
what is a haemorrhagic stroke?
rupture in blood vessels
In an embolic ischemic stroke where does the blood clot come from ?
somewhere else in the brain
what are the key signs of a stroke?
Face paralysis
Arms (lack of movement, no power to grasp)
Speech
Time (phone 999 is is an emergency!)
what is a TIA
think of a TIA as a mini stroke a temporary ischemic attack
not associated with a permanent occlusion but a spasm or temporary clot that has formed and gone away
what is the biggest risk factor for a stroke?
TIA
what should you do if a stroke is suspected?
administer 300mg aspirin
what do CT scans show?
if the stroke is caused by a bleed (haemorrhagic) or a clot (ischemic, this is much more common)
are antiplatlets given if the patient has had an haemorrhagic stroke?
no
what should be done on admission for a patient having a stroke
Image within 24 hours of admission
assess swallowing reflex
stop all medicines
What medicines should especially be stopped when someone is admitted to hospital following a stroke, pending results of the CT scan and swallowing assessment results?
Anticoagulants Thrombolytics Antiplatlets NSAIDS Statins
What can be given as thrombolysis
Aletplase (tissue plasminogen activator)
Aspirin (300mg)
How long does it take to recover from a stroke?
18 months
At what time is the risk the highest for having another stroke?
Risk is highest early after just having had the stroke
but risk still increases as time goes on
What is the secondary prevention checklist for after a stroke?
Antiplatlets/anticoagulants Blood Pressure Cholesterol Diabetes Exercise
should antiplatlets be given after a haemorragic stroke?
NO
they shouldn’t be given on the day of admission or the following day!
What is used to predict risk of stroke in AF patients?
CHA2DSVAS score
if score greater than 2 then antiplatlet is required
IS INR monitoring required for DOACS
no
What does an INR score of <2 mean?
Blood clots too quickly
increase the patients warfarin
What does an INR score of >3 mean
Blood clots too slowly
Decrease the patients warfarin
What is a good INR
between 2-3
is there an antidote for DOACS
no (unlike warfarin which there is a Vit. K antidote for if too much warfarin is taken)
Should antihypertensives be administered immediately after a stroke?
No as the patient is usually HYPO-tensive after a stroke
What antihypertensive should be given to a <55 y/o patient
ACE inhibitor
ARB
What antihypertensive should be given to a >55y/o patient or an african caribbean patient of any age
CCB or thiazide like diuretic
What lipid lowering agent should be given
Simvastatin 40mg
LFT’s and lipids should be checked 1 month after initiation
What should max. simvastatin dose be while on amlodipine?
20mg
Should simvastatin be used in patients who have experienced a haemorrhagic stroke?
Probs not
Statins shouldn’t be used in haemorrhagic stroke patients unless the risk of a CV event outweighs the risk
Is diabetes a risk factor for stroke?
Yes
What lifestyle advice should be offered post-stroke
Exercise
Loose weight
Stop smoking (smoking increases patents risk of stroke by ~50%)
Alcohol?
What is a problem to consider when deciding to crush tablets or open capsules for putting in a feeding tube?
this means that they become unliscenced
consider legal liability issues?
What considerations should be taken into account when using soluble dispersible tablets
they can be used in a feeding tube
consider that they may have faster absorption, shorter duration and faster onset of action compared to when they are used in the non-dispersible form
What medicines should be started with someone that haas had a stroke?
initially stop all the patients medicines start: - aspirin 300mg initially statin anticoagulant antihypertensive
when might the enteral feeding route be used
patient with swallowing difficulties
partial intestinal failure
phsycologial problems
what is TPN
total peripheral nutrition
what is PPN
peripheral parental nutrition
what delivers more nutrition TPN or PPN
TPN
how is TPN usually administered?
through a larger vein in the neck
when is parental nutrition used?
when there is inadequate absorption because of short bowel syndrome
when there is a GI fistula
when there is a bowel obstruction
when there is prolonged bowel rest for one reason or another
when there is severe malnutrition/ significant weight loss
what is enteral feeding
feeding through a tube
what form does the drug need to be in to cross the lipid/GIT membrane?
unionised form
what problems can occur with enteral feeding?
- binding of the drugs to the tube
- direct interaction of the drug and the feed (reduced drug absorption)
- direct interaction of the drug and the feed causing tube blockage
- drug- drug interactions
- need for drug administration on an empty stomach
In E.F what drugs are associated with binding of drugs to the tube?
carbemazepine
diazepam
phenytoin
In E.F what drugs are associated with direct interaction of the drug and the feed, causing reduced drug absorption?
- carbemazepam
- ciprofloxacin
phenytoin
(generally drugs that are highly protein bound)
In E.F what kind of drugs are associated with direct interactions of the drug + feed causing tube blockage?
acidic solutions (e.g. chlorphenamine or promethazine)
In E.F what drugs cause an additional consideration needing them to be administered on an empty stomach
Penicillin
Ketoconazole
What do drug tests test for?
Only specific drugs or drug classes
Can only detect substances when they are present above cut-off levels
After drug screening
Quantative
What does drug screening test for?
immuno-assay
test positive or negative
QUALATATIVE
screening then testing
what is an example of a common screening test
Pregnancy test as it is qualitative not quantative
It doesnt tell you how much baby you have but it tells you that you have a baby
What are the positive aspects of a drug screenig test
inexpensive
easily automated
quickly produce results
What lab drug testing methods are used?
- gas chromatography
- high performance liquid chromatography
- gas chromatography
- GC + MS + MS
- LC + MS
What factors are considered in test reliability
test sensitivity and test specificity
what is test “sensitivity”
proportion of + results a testing method correctly identifies
True Positive Rate
what is test “specificity”
proportion of - results a testing method correctl identifies
True Negative Rate
What is the limit of detection
lowest amount of the analyse that can be dented but not quantified
Lower than LoQ
What is the limit of quantification
Lowest amount of analyse in the asme that can be quantataimvley determined with suitable precision and accuracy
Higher than LoD
What is window of detection
Length of time substance or metabolites can be detected in a biological matrix
What should % accuracy be for HPLC assay of drug in a dosage form?
> 99.5%
What should % accuracy be for HPLC assay of drug metabolite in plasma be?
> 90%
When does cross reactivity occur?
When a test cannot specify between substances tested for and substances that are chemically similar
What is the range of specificity
A specific method is one that measures only ONE particular analyte and which does NOT suffer interference if another substances are present in the sample MOST specific - IR Spectroscopy then HPLC and GC then titration then UV (not very specific)
What is the test matrix?
Biological specimen used for testing for the presence of the drug
What window of detection does breath have
Short (mins-hours)
What window of detection does blood have
short (mins-hours
What window of detection does oral fluid have
short (mins to hours)
What window of detection does urine have have
medium (hours to weeks)
What window of detection does sweat have
medium (hours to days)
What window of detection does meconium have
long (weeks to months)
What window of detection does hair have
very long (days - years)
what is a point of care test (POCT)
conducted when a specimen is collected
What do specimen validity tests determine
whether a speccing has been diluted, adulterated, substituted
What do specimen validity tests for urine determine
Compare urine specimen characteristics with acceptable density and composition ranges for human urine
- detect any adulterants
creatine and pH analysis
What levels indicate that a urine specimen has been diluted?
creatinine concentration > 2mg/DL or <20 mg DL
Why is infection especially bad in patients that are suffering from cancer/malignancy?
They cannot mount a white cell count to an infection and fight it off!
What causative organism is likely to be casing infected COPD
moraxhalla
strep. pneumonia
haemophillus influenzae
What antibiotic is usually 1st line for respiratory infections?
amoxicilin
What organism is likely to cause cellulitis
Staph. aureas
What antibiotic is good for cellulitis
Fluloxacillin
How are aminoglycosides excreted?
renally
How are glycopeptides excreted?
renally
How are cephalosporins excreted?
renally
How are penicillins excreted?
renally
How are anti-vitals excreted?
renally
How are macrolides excreted?
hepatically
How are tetracyclines excreted?
hepatically
How are isoniazid excreted?
hepatically
How are rifampicin excreted?
hepatically
How is ceftriaxone excreted?
both hepatically and really
what are the three types of ACUTE renal failure
pre-renal
intra-renal
post-renal
What happens in pre-renal failure
reduction in renal perfusion
(compromised blood supply to the kidney caused by maybe traumatic blood loss, cardiac failure or drugs that cause reduced renal perfusion)
What are the different types of intra-renal failure
renal tubular necrosis
interstitial nephritis
glomerulonephritis
What happens in ‘renal tubular necrosis’
intra-renal failure
- renal hypo=perfusion
caused by nephrotoxicity (caused by nephrotoxoty may be caused by antibiotis)
what happens in interstitial nephritis
Intra-renal failure
nephrotoxicity caused by penicillins, cephalosporins
nephritis is inflammation of the kidney
what happens in Glomerulonephritis
immune complexes form glmoerulonephritis is inflammation of the kidney caused by an immune response e.g. - endocarditis - phenytoin
what happens in “post-renal” failure
urinary tract obstruction
- kidney stones
- thrombosis
- tumours
- benign prostatic hypertrophy
what kind of renal replacement is used in acute renal failure
hemofiltration (if <10ml/min)
what is chronic renal failure
progressive deterioration over months or years
when do symptoms of chronic renal failure start to be seen?
when renal function is <30 ml/min
what is required at end stage renal failure
renal replacement
- hemodialysis
- chronic ambulatory peritoneal dialysis
- kidney transplantation
what may cause chronic renal failure
- chronic glomerulonephritis
- chronic pylenephritis
- interstitial nephritis
- hypertension
- urinary obstruction
- polycystic kidney disease
- diabetes mellitus
How is distribution affected in renal impairment?
- distribution of water soluble drugs (fluid retention/dehydration)
- changes in pH
- decreased binding of drugs to albumin (consider acidic drugs like warfarin and phenytoin)
- increased binding to alpha-1-acid glycoprotein (AAG) (consider basic drugs such as propranolol, verapamil, prazosin etc, they become highly bound to AAG during renal failure .)
What changes are seen to albumin in renal failure
Albumin levels are lower in kidney/renal failure especially if it is nephrotic kidney failure
How is the volume of distribution of Digoxin altered in renal failure?
It is decreased
How are drugs eliminated renally?
Glomerular Filtration (passive)
Active secretion
Reabsorption
what drugs are renally excreted via glomerular filtration
small MW drugs unbound drugs (fu) Drug Cl(renal)= fuXGFR
What happens in active renal secretion?
Organic ion/cation transport proteins do the secretion
- efflux transporters (PgP)
not inhibited by protein binding at all
Drug Cl (renal)>fu X GFR
How are drugs renally absorbed?
Passive (small/unionised/lipophillic drugs) Active (glucose and vitamins) pH dependent (weak acids/bases with pH close to urine) Drug CL (renal) < fuX GFR
What is the general eon for renal clearance (remember for any drug all these processes can occur)
Renal Clearance = filtration + secretion - reabsorption
What drugs are metabolised in the kidney
cortisol
insulin
vit D
therefore there clearance/activation is reduced in renal failure
How is hepatic metabolism altered in patients with renal failure?
Hepatic metabolism is altered - effects on CYP - inhibitory metabolites may accumulate - regeneration of the parent drug Varies according to CYP enzyme - accumulation of waste products or toxic metabolites/ accumulation of renally cleared metabolites
IS it alright to give someone with renal failure morphine?
You should be concerned about giving someone with renal failure morphine because of its associated toxic metabolite accumulation in renal impairment
What exogenous marker of renal failure us used?
Cr EDTA
consider it as actual GFR
What endogenous marker of renal failure is used?
urea
creatinine
cystatin C
What are some limitations associated with using the Cock-croft gault equation
Cock-croft Gault eqn. assumes that the patients…
- creatinine concentration is at steady state (this isn’t true if renal function is rapidly changing)
- creatinine production is normal
How is creatinine produced?
Creatine (liver) –> creatine phosphate (muscle) –> creatinine
When/ in what patient groups is creatinine production not always normal?1
- creatinine production is lower in the elderly/ malnourished people/ people with muscular dystrophy
- lower in children
- lower if severely under or overweight
Cock-croft gault equation for estimating renal function often OVER-ESTIMATES renal function in elderly patients
What is a normal BMI
18.5-24.9
What is an underweight BMI
<18.5
What is an overweight BMI
25-29.9
What is a severely obese BMI
35-39.9
What is a morbidly obese BMI
> 40
What PK factors does obesity impact upon?
Drug VD
Drug Clearance etc…
What drug characteristics does VD depend upon?
MOleculular size
ionisation state
water/lipid solubility
What kind of tissue is increased in obesity?
Adipose tissues Muscle and connective tissues Blood volume alpha-1 acid glycoprotein cholesterol triglycerides free fatty acids
All these factors alter drug distribution and protein binding
How much water does adipose tissue contain?
30% water
How is hepatic function altered in obesity?
Phase 1 metabolism-CYP enzymes are affected (CYP3A4 function decreases while the others increase)
Phase 2 metabolism increases
Liver blood flow increaes
Consider does the patient have a bigger liver?
how is renal function altered in obesity?
increased renal plasma flow (increased C.O., increased blood volume, increased hydrostatic pressure) increased GFR (no change in renal hypertrophy)
what age is a preterm neonate
born at <37 weeks gestation
what age is a term neonate
born at 37-42 weeks gestation
what age is a post-tern neonate
born at >42 weeks gestation
what age is a neonate?
0-28 days old
what age is an infant
28 days –> 24 months
what age is a child
2-12 yrs