Haematology Flashcards
What is warfarin?
- anticoagulant
- vitamin K antagonist
- 48-72 hours for full anticoagulant to develop
What is INR and what levels are acceptable in dentistry?
- blood test used to calculate the INR ratio
- prothrombin time divided by reference plasma value
- INR of 1 for a healthy individual
- 2-4
- any invasive treatment must have an INR of under 4
What drug is used if an immediate anticoagulant effect is needed?
- low molecular weight heparin
What are direct-acting oral anticoagulants?
- DOACs
- apixiban
- dabigatran etexilate
- edoxaban
- rivaroxaban
- regular monitoring not required as with warfarin
What does dabigatran etexilate act on?
- reversible inhibitor of free thrombin, fibrin-bound thrombin and thrombin induced platelet aggregation
What do apixiban, edoxaban and rivaroxaban act on?
- reversible factor Xa inhibitors
- prevent thrombus development
What is simvastatin?
- lipid lowering medication
- HMG CoA reductase inhibitor
- treats hypercholesterolaemia
What is furosemide?
- loop diuretic
- can exacerbate diabetes (less than thiazide diuretics)
- controls hypertension
- combined with other hypertension medications
What antifungals can be prescribed with warfarin?
-nystatin
- safe for use in warfarin patients
- -azole antifungals must be avoided
- potentiates the anticoagulant effect
- increased risk of myopathy when taking statins
When is an INR required before performing dental treatment?
- no more than 24 hours before the procedure
How is haemostasis achieved after extraction from a warfarinised patient?
- local anaesthetic
- containing vasoconstrictor
- short, 27 gauge needle to minimise tissue damage
- local haemostasis
- pack sockets with absorbable haemostat dressing
- place sutures (ideally resorb ably_
- pressure applied by patient biting on gauze
- atraumatic technique for extraction
What should a patient taking apixaban be told before having an extraction?
- to change their drug regime prior to treatment
- miss morning dose
- take usual evening dose (4 hours after homeostasis achieved)
What is haemophilia A?
- factor VIII deficiency
What is haemophilia B?
- factor IX deficiency
What are the different severities of haemophilia?
mild - 6-40% factor present
moderate - 2-5% factor present
severe - <1% factor present
