Anticoagulant Flashcards
list 2 drug that reduce rivaroxaban level
- p-gp inducer
- CYP3A4 inducer
what is the pharmacokinetic of the anticoagulant action of oral warfarin
onset: 24-72hrs
peak: 5-7 days
duration: 2-5 days (due to the long half life of some of the factor eg II T1/2 50hrs)
where is warfarin metabolise + which enzyme
in the liver, primary by CYP2C9
list 3 a/e of heparin/LMWH
- bleeding
- thrombocytopenia (lesser risk w LMWH)
- increase risk of epidural/spinal haematoma & paralysis in pt receiving epidural/spinal anaesthesia or spinal puncture
what is the pharmacokinetic for dabigatran
onset: ~1hr
peak: 3h
duration: 3-5 days
list examples of significant drug-drug interactions with warfarin
- paracetamol >2 weeks at high dose >2g/day (increase risk of bleeding)
- allopurinol, NSAIDS, salicylates, PPI, metronidazole (increase risk of bleeding)
- barbiturates, corticosteroids, spironolactone, thiazide diuretic (reduce drug effect)
list 1 adverse effect of rivaroxaban
bleeding
list example of drug-drug interaction with dabigatran that increase the risk of bleeding
- antiplatelet
- anticoagulants
- fibrinolytic
- NSAIDS
- ketoconazole
what is the pharmacokinetic of heparin
onset: 5-25min
duration: 4hr
list 1 drug-drug interaction that increase the risk of bleeding with heparin/LMWH
SSRI (selective serotonin reuptake inhibitor)
what is the 4 contraindication over the use of heparin/LMWH
- hypersensitivity to pork product
- active bleeding
- thrombocytopenia
- antiplatelet antibodies
list example of drug-drug interaction with rivaroxaban that increase the risk of bleeding
- antiplatelets
- anticoagulants
- NSAIDS
- p-gp inhibitor
- CYP3A4 inhibitor
name a reversal agent for rivaroxaban
andexanet alfa
does dabigatran have a short or long bioavailability, what advice should be given to patient
short, instruct pt to swallow the medication whole (enteric coated)
a 62 y/o man admitted with DVT is stabilised and restarted on a lower dose of LMWH overlapped with warfarin in preparation of discharge. why is warfarin more appropriate for outpatient therapy
a) warfarin can easily be administered orally
b) warfarin is a safe drug with no drug-drug or drug-food interactions
c) the risk of bleeding with warfarin is less than any other anticoagulant
A
list the 3 adverse effects of warfarin
- haemorrhage/bleeding
- hepatitis (greater risk in >60 y/o, male, warfarin <1 month)
- cutaneous necrosis due to reduce blood supply to adipose tissue, typically 3-5 days after treatment initiated