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