15. Bleedingg tendency, bruising, Warfarin Flashcards
what measurement is used in warfarin therapy management?
INR- range between 2-4 roughly
how to manage a low INR
ask patient if missed doses & consider increasing the dose temporarily & measure INR in few days again
Common interactions of warfarin- which ones enhancer? inhibitors?
Warfarin is enhanced by alcohol, allopurinol, paracetamol, SSRIs, lipid-regulating drugs, cranberry juice, influenza vaccine
warfarin is reduced by oral contraceptives and St John’s wort.
what to give in warfarin overdose/toxicity
vitamin K, (plasma if bleeding)
what enzyme system in the liver has warfarin as its substrate?
CYT-P450
name some contraindications to warfarin?
hypersensitivity ,
Haemorrhagic stroke, significant bleeding.
Within 72 hours of major surgery with risk of severe bleeding.
Within 48 hours postpartum.
Pregnancy ,
Drugs -steroidal anti-inflammatory drugs (NSAIDs), selective serotonin reuptake inhibitors (SSRIs), venlafaxine or duloxetine.
, major bleeding disorder (eg, haemophilia, chronic kidney disease).
Potential bleeding lesions - eg, active peptic ulcer, oesophageal varices.
What is dabigatran?
Competitive, direct thrombin inhibitor; thrombin enables fibrinogen conversion to fibrin during the coagulation cascade, thereby preventing thrombus development
why would dabigatran be prescribed instead of warfarin?
Dabigatran etexilate, rivaroxaban and apixaban–>
Primary prevention of venous thromboembolic events in adult patients who have undergone elective total hip replacement surgery or total knee replacement surgery.
Prevention of stroke and systemic embolism in adult patients with non-valvular atrial fibrillation (NVAF), with one or more risk factors, such as prior stroke or transient ischemic attack (TIA); age ≥ 75 years; heart failure (NYHA Class ≥ II); diabetes mellitus; hypertension.
Treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE), and prevention of recurrent DVT and PE in adults
