Kassandra Muirhead
Blood clots are normally protective but they can also be harmful leading to diseases such as deep vein thrombosis pulmonary embolism or stroke smoking is a major cause of heart disease and increases the risk of heart attacks due to atherosclerosis here the narrowing and clogging of the arteries with tar and fatty substances increases the risk of blood clotting see
I told you luckily these conditions can be treated with anticoagulants sometimes incorrectly labeled blood thinners which work by reducing these unnecessary blood clots in australia there are currently four types of anticoagulants used one traditionally and three recently approved by the tga these are warfarin dabigatran rivaraxaban and apixaban since the 60s
Thromboembolic diseases were only treated with one oral anticoagulant drug warfarin warfarin works by antagonizing the action of vitamin k an essential component involved in the activation of certain clotting factors 2 7 9 and 10 when major bleeding occurs as a result vitamin k is oxidized into vitamin k epoxide however the liver enzyme vitamin k epoxide reductase
Complex 1 is capable of recycling vitamin k epoxide back into vitamin k by strongly inhibiting vitamin k epoxide reductase complex 1 warfarin hinders this process and the liver produces defective clotting factors in 2008 rivaraxaban and debigatron were approved by the tga while a pig span was later approved in 2012. unlike warfarin river accident and apixaban
Are competitive reversible antagonist that activate factor 10 to 10 a which assists in the formation of thrombin while dopigatram antagonizes factor 2a which converts fibrinogen to fibrin so how does warfarin differ to the noax let’s start with the advantages warfarin is a well-known drug it can be administered to patients with valvular atrial fibrillation it’s
Low in cost but most importantly there are antidotes available on the other hand noex have a faster onset of action fixed dosing stable therapeutic levels predictable pharmacokinetics and pharmacodynamics it has a shorter half-life and patients pending surgery do not have to undergo bridging but of course there are also some disadvantages of both warfarin has a
Narrower therapeutic index slow onset and offset of action and multiple drug and food interactions for example with ibuprofen naproxen allergy medications vitamin k rich food and many antibiotics furthermore patients are required to undergo bridging pre-surgery and with unpredictable pharmacokinetics and pharmacodynamics frequent inr monitoring is essential nowaks
Also have their own issues for instance they cannot be administered to patients with valvular atrial fibrillation additionally patients require twice daily dosage while those with renal impairment need dose adjustment there is also a lack of long-term safety data and it is known that the nomads can cause git hemorrhage myocardial infarction and intracranial bleeding
Lab monitoring tools are also unreliable and no acts are very very costly now let’s look at some key issues that limit the use of both drugs there are certain people who cannot take warfarin as it poses serious health risks to them these include pregnant women which may lead to fetal warfare and syndrome in the newborn patients who are actively bleeding for example
Due to a bleeding or blood cell disorder like hemophilia patients with peptic ulcers or post organ surgery or biopsy and those with kidney and liver failure alternatively whilst the noaaks have a faster onset of action the drug effects rapidly diminish over time skipping a dose may lead to an increased risk of embolism and prolonged use of rivaraxaban can lead to
Osteoporosis the noaaks are also contra-indicated in elderly patients with unstable inr values as these patients may be suffering from impaired cognition or depression the nomaks are metabolized by the liver hence they’re contra indicated in patients with liver dysfunction patients with decreased renal clearance specifically with the creatinine clearance of less
Than 15 mls per minute should also avoid the no wax as there is an increased risk of the drugs being cleared unchanged through the kidney taking the noise with anti-platelet agents such as aspirin and non-steroidal anti-inflammatory drugs are discouraged as this drug interaction consequently leads to an increased risk of bleeding hmm what’s left to say oh taking
The noah’s result in reduced plasmid levels but most importantly note that unlike warfarin there are no antidotes available for the noax remember this man considering all that has been presented what do you think is the best drug for this patient you
Transcribed from video
Warfarin vs New Oral Anticoagulants [FINAL] By UTS Pharmacology
