PSA Flashcards
What is d dimer
What is a positive result
What does it tell you
Fibrin degradation product
Positive if it is raised
Suggests there may be a clot
what are the different types of anticoagulants
Vitamin K antagonists
Direct thrombin inhibitors, direct Xa inhibitors (DOACs)
Indirect Xa and thrombin inhibitors - Heparin
give some examples of direct thrombin inhibitors
dabigatran, edoxaban
give some examples of direct xa inhibitors
apixaban, rivaroxaban
give some examples of direct xa inhibitors
apixaban, rivaroxaban
what patients should DOACs not be used in
antiphospholipid syndrome
caution - elderly
renal impairment, egfr <15
What are some limitations / considerations with warfarin
Narrow therapeutic window
Frequent monitoring and dose adjustment
Interaction with food and drugs, chemotherapies
Less effective than LMWH for patients with cancer
what should you consider when deciding anticoagulant for DVT/ PE treatment
Renal function
Active cancer
Antiphospholipid syndrome
what blood test is used to measure warfarin and extrinsic pathway
prothrombin time
what blood test is used to measure heparin and intrinsic pathway
activated partial thromboplastin time
what is warfarin most commonly prescribed for
AF
Heart valves
VTE prophylaxis
what do you need to consider in a patient with cancer if wanting to anticoagulate
account tumour
site, drug interactions
including cancer drugs,
and bleeding risk
what is a side effect of unfractioned heparin
heparin thrombocytopaenia (dont get this with LMW heparin - dalteparin)
what is a normal INR
what is a target INR for those on warfarin
Normal <1.1
On warfarin 2-3
what vte prophylaxis should be used in pregnancy and why - what about those currently on warfarin for heart valve anticaog
LMWH, does not cross placenta and not in breast milk
Warfarin teratogenic
what anticoagulantion is generally used for treatment of an acute venous thrombotic event and why, what are exceptions
LMWH or DOAC - faster to work than warfarin
Can use warfarin if problem with renal function - need more monitoring and dose adjustments
what anticoagulation is generally used for short term vte prophylaxis, give some examples of clinical sceanarios
LWMH or DOAC eg post surgical prophylaxis, pregnancy (LMWH)
what anticoagulation is generally used for long term vte prophylaxis and why
DOAC or warfain
Both oral
list some conditions where warfain is the only anticoag indicated
Heart valve vte prophylaxis
AF (sometimes, only if DOAC is problem)
what conditions should you consider when deciding about anticoag
Renal function
Age - elderly (caution DOACs)
Cancer (DOACs interact w certain chemos)
Antiphospholipid (DOAC contraindicated)
What is the mode of action of tranexamic acid
Antifibrinolytic
Binds to plasminogen and inhibits it so plasmin not secreted = fibrin mesh stays in place and prevents bleeding
What are the adverse effects of aminoglycosides
Kidney injury
Hearing changes / loss - can affect cochlear
What group of patients are aminoglycosides contraindicated in
Myasthenia gravis
What is a loading dose and why is it used
It is a high dose of a drug that is used to build up plasma concentration faster than a lower dose
The ‘steady state’ of a drug - which is when plasma concentration production and elimination are matched, if you aim to reach steady state with low dose it will take a while to get there. If use a higher dose you push the start point up so that you can then use a lower dose later to maintain.
Example - 300 mg aspirin, followed by 75 mg maintenance
what are the contraindications to NSAIDS
GI bleed Ulcer Asthma Severe heart failure Cerebrovascular event
what should you check with prescribing paracetamol
liver function
severe cachexia
what should you check before prescribing nsaids
renal function platelets any blood thinners digoxin - dose needs adjusting down steroids - increased risk of gi bleed
what is the risk of nsaids during pregnancy
first trimester miscarriage
third trimester - closure of ductus arteriosus, risk of pulmonary hypertension
List the common nephrotoxic drugs
ANA Antihypertensives NSAIDs Aminoglycosides (perfusions/ acute tubular necrosis)
Which drugs can cause a metabolic acidosis because of effects on kidney
Metformin
Diuretics (reduced bicarb absorption and increase in Cl)
NaCl - raised Cl
List some drugs that can cause electrolyte dysfunction via kidneys and may need dose adjustments
(all affect K or Na via action on kidneys)
Trimethoprim - hyperkalaemia
Ampherotericin B - anti fungal
Litium - hyponatraemia
Immunesupression - ciclosporin, tacrolismus
Digoxin - hyperkalaemia
What is the mechanism of NSAIDs, how does this link to the types available to prescribe
NSAIDs inhibit prostaglandin production via inhibition of COX-1 or COX-2 enzymes that convert aracidonic acid to prostaglandins.
COX-1 pathway involved in homeostasis
COX-2 pathway involved in inflammation
There are NSAIDs that have mixed COX-1 and COX-2 actions, and some selective COX-2 (coxibs) - celecoxib and etoricoxib
what are the common sides effects of NSAIDs and why
- GI bleed - via effects on COX-1 pathway
- Nephrotoxicity - via afferent arteriole vasoconstriction and under perfusion leads to low GFR
- HTN - via loss of prostaglandin vasodilation
what are some of the complete contraindications to NSAIDs
Previous GI bleed
Severe HF
eGFR <30
Uncontrolled hypertension
what is a life threatening allergy that you should check for before starting any nsaid
asthma - can have allergy to nsaid
what are common drug interactions with nsaids
digoxin (raised BP)
steroid (immune supression effect?)
other NSAIDs
List some common non-specific NSAIDs
Aspirin Ibuprofen Mefanamic acid Diclofenac Indometacin Naproxen
List some cox-2 specific NSAIDs
Coxibs
Celecoxib
What process should you use to consider if a patient is eligible/ should be started on an NSAID
- Systems contraindications - stomach, kidneys, blood, airways (previous bleed, gfr <30, uncontrolled htn, previous CVD/ PVD, asthma)
- Drug contraindications - another nsaid, digoxin, steroid
Then categorise as high, medium, low risk for adverse event
How should you manage high, medium and low risk of adverse event (bleed) when prescribing NSAIDs
High risk - cox-2 only plus PPI
Medium risk - cox-2 or nsaid plus ppi
Low risk - nsaid
If somebody has a hx of ischemic hd, cerebrovascular disease, of peripheral vascular disease - how should you prescribe an NSAID
There is a risk of HTN and bleeding with a non-selective NSAID
Should have low dose ibruprofen
COX-2 inhibitors and diclofenac are contraindicated in this group
Describe the analgesic ladder
Step 1: simple analgesia - paracetamol (check liver function and weight), NSAIDs
Step 2: weak opioids (codeine, dihydrocodeine, tramadol)
Step 3: strong opioids (morphine, oxycodone, diamorphine, bupronorphine)
what should a PRN dose of an opioid be
1/6th the total 24 hours dose
How should you work out opioid dose conversions
Opioid conversion chart
What is the difference in strength between codeine and morphine
morphine is 10x stronger, so need 1/10th of the dose
what are the common side effects of opioids
constipation nausea sedation dry mouth sometimes confusion sometimes respiratory depression
why is oxycodone preferable to morphine for some people
Less side effects
Double the strength of morphine
When filling out a prescription what do you need to ensure
Name of drug Suspension - immediate release, modified release, oral etc strength of tablet - eg 500 mg total dose - eg 1500 mg TDS Route - PO, IV, IM etc duration - how many days to take number of tablets to be dispensed
what do you need to check before prescribing opioids
renal function
need dose adjustments if impaired
need low dose and frequency
What antibiotics can be prescribed to breastfeeding mum with UTI
Amoxicillin (weak acid so doesn’t accumulate in breastmilk)
Cefalexin
Trimethoprim
What UTI antibiotic is contraindicated in breastfeeding and why
Nitrofurantoin - can cause haemolysis
Mechanism of action is DNA damage
Describe the first and second line treatments for type 2 diabetes
First line - metformin (need to check renal function, contraindicated if gft <30 and need reduced dose if gfr <45)
Second line - gliptins - DPP-4 inhibitors
Pioglitazone
Sulfonylureas
SGLT-2 inhibitors
What is a normal hba1c level
<42
42-46 - prediabetes
>47 - diabetes
What are second and third line treatments for type 2 diabetes
Two hypoglycaemics Metformin + second line Or Two second line Can then do triple therapy if needed Then insulin
In what clinical situations is insulin used
Type 1 diabetes
Type 2 diabetes- last resort
Pregnancy - gestational diabetes
Hyperkalaemia
rapid onset insulin - how quick does it work and how long
10-15 minutes onset
works 3-5 hours
list some of the rapid insulins
lispro (Humalog®), aspart (NovoRapid®) and glulisine (Apidra®)
what is the onset and duration of long acting insulin
1 hour
24 hours
taken once a day
list some long acting insulins
glargine (Lantus®) and detemir (Levemir®).
what is the onset and duration of short acting insulin
30 mins
8 hours
what is one of the issues of short acting insulin
can cause hypos in between meals
list some short acting insulin
Actrapid® and Humulin S®.
what is the onset and duration of intermediate insulin
1.5 hrs onset
24 hours duration
what things do you need to discuss with a patient regarding their insulin regimen choice
glycaemic control - different regimes have different outcomes with this
flexibility - basal bolus most adaptable but it requires the most input from patient
burden/ patient involvement - one or twice daily regimes are less burdensome but poorer control
How regular are meals
Are days predictable or unpredictable
what are the indications for an insulin pump
basal bolus regime not worked - poor glycaemic control
having hypos with multiple injection regime
why should you never omit insulin in a T1 diabetic
15 mins of no insulin can be enough to cause DKA
what are some of the indications of IV insulin
DKA, HHS ACS Post cardiac event if hyperglycaemia Surgery and diabetes High/ fluctuation glucose - eg sepsis
what is the traditional fluid regime
Saline 0.9% + 20mmol potassium chloride (over 8 hours)
Dextrose 5% + 20mmol potassium chloride (over 8 hours)
Dextrose 5% + 20mmol potassium chloride (over 8 hours)
outline an algorithm for fluid resuscitation/ prescribing / how to chose a regimen
- Are they hypovolaemic - yes - 500 mls NaCl (or Hartmann’s if vomiting as has K in)
- Once normovolaemic - review to identify any existing deficits or ongoing losses - add these to routine maintenance. Do same with electrolytes.
- Consider any special circumstances/ redistrubution - HF, Renal failure, sepsis, hyper/ hyponatraemia, refeeding syndrome
- Calculate maintenance fluids
How do you calculate maintenance fluids
30 ml/kg Or 25 mls/kg if elderly, HF or RF Use ideal BW if obese 1 mmol/kg/ day for Na+, K+, Cl- 50-100g glucose a day to prevent starvation ketosis