SESSION 2 Flashcards
In gentamicin prescribing what should you do if peak level is too high?
Lower the dose
In gentamicin prescribing what should you do if trough level is too high?
Increase the interval between the doses
How should you monitor a pt on naloxone?
RR, oxygen sats and a blood gas
What drugs most commonly cause acute interstitial nephritis?
Beta-lactam antibiotics
Fluoroquinolone antibiotics
PPIs
NSAIDs
Outline the difference in consideration of Tx of acute and chronic hyponatraemia
Acute hyponatraemia needs urgent treatment to prevent cerebra oedema. Chronic hyponatraemia is more at risk from rapid correction of hyponatraemia with the risk of osmotic demyelination syndrome. Serum sodium should not rise by more than 10mmol/L in the first 24 hours in hyponatraemia and then no more than 8mmol/L every 24 hours thereafter
When correcting hyponatraemia, serum Na+ should not rise by more than what in the first 24 hours?
10mmol/L
When do signs of osmotic demyelination tend to occur after too-rapid correction of hyponatraemia?
3-4 days after treatment
Signs of osmotic demyelination?
Confusion
Dysarthria
Mutism
Dysphagia
Lethargy
Affective changes
Seizures
Spastic quadriplegism
Coma
Death
Drug Tx of orthostatic hypotension?
Fludrocortisone
MOA of fludrocortisone for orthostatic hypotension?
Binds to mineralocorticoid receptors in the kidneys and increase sodium reabsorption which increases blood pressure
Reversal agent for warfarin?
Vitamin K
Reversal agent for dabigatran?
Idarucizumab
Reversal agent for rivaroxaban?
Andexanet Alfa
Reversal agent for apixaban?
Andexanet Alfa
What is andexanet Alfa?
a recombinant form of human factor Xa protein which binds specifically to apixaban or rivaroxaban, thereby reversing their anticoagulant effects.
Can DOACs be used if renal function <15?
Nope!
What are the 2 isomers of warfarin?
R and S stereoisomers of the drug.
S-warfarin is 3-5 times more potent an inhibitor of the vitamin K epoxide reductase complex, the target of action, than R-warfarin. S is more common. S is metabolised by CYP450 so this drug can be heavily influenced by other drugs
DOACs vs warfarin?
Comparable effectivenebrss for VTE
DOACs have lower rates of major bleeding events
Warfarin has lower rates of GI bleeding
Outline the HAS-BLED score?
It’s a score where each point is 1 point and it assesses the bleeding risk for a pt going on to anticoagulation
• hypertension that is uncontrolled or >160 systolic
• Liver disease (cirrhosis or bilirubin >2x normal with AST/ALT/AP >3x normal)
• Renal diseases (dialysis, transplant, Cr >200)
• Stroke Hx
• Bleeding RF or major bleeding event
• Labile INR (unstable or high INRs or time in therapeutic range <60%)
• Elderly >65
• Drugs (that increase risk of bleeding) or alcohol >=8 drinks a week
Half life of warfarin vs DOAC?
What does this mean for when a pt needs surgery?
Warfarin - ~36-40 hours
DOACs 7-14 hours
If a pt is on warfarin you must stop it 3-5 days before surgery and make sure INR <1.5
DOACs can be stopped 48 hours before surgery
Do you need to stop antiplatelets for surgery?
Yes 5 days before
Outline CT rules for a pt with head trauma and on an anticoagulant
If head trauma + anticoagulant = CT head within 8 hours!
If any of the following = CT head in 1 hour
◦ GCS <13 initially
◦ GCS <15 at 2 hours post-injury
◦ Suspected skull or basal skull fracture
◦ Seizure since injury
◦ Focal neurological deficit
◦ >1 episode of vomiting