Anticoagulant √ Flashcards
What are the 2 genetic condition that produce hypercoagulable state
Leiden mutation
Gene 20210A mutation
what is secondary acquired thrombosis
HITTS
what are some hyper coagulable conditions
Risk factor for VTE event
Wells score DVT
wells score PE
3 DVT symptoms
unilateral leg swelling
Pain behind the knees when the foot is flexed
palpable cord in superficial
5 PE symptoms
Dyspnea
tachycardia
Tachypena
chest pain
chest tightness
DVT diagnosis
Elevated D dimer >240
wells score ≥2
PE diagnosis
V/Q mismatch
Elevated D dimer
Simplified wells score >4
VTE treatment Pathway
Name 9 Patients that are at risk of major bleed on a anticoagulant
The first few days and weeks of therapy
Age 65+
on NSAID, Aspirin, or GI bleeding
High-risk fall patients
Recent Trauma Patients
Heavy Alcholol use
Cancer
Renal failure
Cerebrovascular disease
In the Treatment pathway, what are the 2 criteria that allow use of Fibronlytics
DVT at risk for Gangrene and limb loss
Hemodynamically unstable PE (<90 SBP, blood loss, Shock, any heart abnormality)
patient is not in shock or <90 SBP when can we still think about using fibrinolytics
What are the 10 contraindications for Fibrinolytics
1.Previous intracranial hemorrhage at any time
2.Intracranial or intraspinal surgery within 2 months
3.Significant closed head or facial trauma within 3 months
4.Active internal bleeding (not including menses)
5.Ischemic stroke within 3 months (except ischemic stroke within 4.5 hours)
6.For streptokinase, prior streptokinase treatment within the previous 6 months
7.Known structural vascular lesion (e.g., arteriovenous malformation, AVM)
8.Suspected aortic dissection
9.Severe uncontrolled hypertension (unresponsive to emergency therapy)
10. Known malignant intracranial cancer
What needs to be administered before Fibrinolytics?
Heparin
Do we stop heparin when given with fibrinolytics?
In America common to stop but can continue if needed
Loading dose and maintenance dose of heparin?
LD - 80 units/kg bolus IV (DNE 10,000 units)
Main - 18 units/kg/hour (DNE 2,150 per hour)
USE ACTUAL BODY WEIGHT
ITS UNITS
Which Fibrinolytics can we use for DVT or PE
Alteplase - mainly seen
Streptokinase
Urokinase
How do we administer Alteplase
PE: 100mg IV infusion over 2 hours once
Cardiac arrest: 50mg IV Bolus once
What do we give to a patient who has a PE and has a cardiac arrest
50mg IV bolus once
How do we administer Streptokinase
250,000 IV units once
100,000 contiuos IV over 24 hrs
How do we adminster Urokinase
4,400 units/kg over 10mins
4,400 units/kg over 12 hours
VTE strats
What meds can we give for acute phase treatment (day 5-10) of VTE
Heparin
LWMH
Fondaparinix
Rivaroxaban or Apixaban
What are the 2 LWMH
enoxaparin (lovenox)
Dalteparin (fragmin)
What is Fondaparinux
Anti Xa heparin Derivative
Apixaban dosing for VTE
10mg PO BID 7 days
5mg BID for 3 months
2.5 mg after 6 months
Rivaroxaban dosing for VTE
15 mg po BID for 21 days
20 mg QD for 3 months
10 mg QD after 6 months
Dabigatran Dosing for VTE
heparin 5-10 days
150 mg po BID
Edoxaban Dosing for VTE
Heparin for 5-10 days
Edoxaban 60 mg daily for 6 months
Dabigatran 150 mg BID for lifetime
Warfarin Dosing for VTE
heparin at least 5 days
while taking warfarin QD until INR reaches ≥ 2
then send home with range 2 - 3 for at least 24hrs
Can heparin dissolve clots?
No only fibrinolytic can like alteplase
which heparin is NOT renal excreted
Unfractionated heparin
What labs do we order with Heparin
CBC
aPPT
PT/INR
BUN
Serum Creatine
what routine labs do we run with Heparin?
aPPT/ Anti-Xa, 6 hours after bolus,
every 6 hours till 2 therapeutic then monitor daily
if change in dose every 6 hours
CBC
daily if pretreatment <100,000 platelets
every 72 if pretreatment >100,000
Goal aPPT and Anti Xa
aPPT 50-77
Anti Xa 0.3-0.7 IU/ml
What are the 3 major side effect of Heparin
Narrow therapeutic window
Heparin-induced thrombocytopenia (HIT)
Hemorrhage (minor to major)
Hypersensitivity reactions (rare) – fever, chills,
Hyperkalemia (rare) - only one teach saw
Osteoporosis (rare)
Reverse anticoagulation by stopping infusion +/- administration of protamine
SC Heparin dosing
5,000 units IV or 333 units/kg SC x 1 followed by 250 units/kg SQ BID
or
110% of total daily IV requirements if switching from IV to SQ for discharge
NOT VERY COMMON
What option do we have with LWMH
Enoxaparin (Lovenox)
Dalteparin (Fragmin)
Which heparin has a lower HIT rate
LWMH
do we monitor aPPT or anti Xa in LWMH
Anti Xa
Normal dosing for Enoxaparin
1mg/kg BID or 1.5-2mg/kg daily
Normal dose for Dalteparin
1st Month 200IU/kg max 18,000
2- 6 months 150 IU/kg max 18,000
Both SQ and daily
4 patient populations that require special dosing for LWMH
- obese
- renal impairment Crcl <30
- elderly
- cancer
How do I recognize HIT
Platelet count drop of 50% (even if nadir > 150,000) from baseline
Venous or arterial thrombosis
Skin lesions at heparin injection sites
Acute systemic (anaphylactoid) reactions that occur after a bolus of IV heparin
HIT vs HAT onset
HIT 4-14 days unless 3 had heparin 3 months ago ≤ 1day onset
HAT <4 days faster onset
4 T test ranges and the percentage of HIT
≤ 3 low
4 - 5 intermediate
6 - 8 high
What do we do when a patient has HIT
DC heparin
initiate anti-coag Fondaparinux, Bivalirudin, Argatroban
transition to oral anti-coag to platelet recovery of ≥150^10
continue anti-coag
1 month or until ≥ 150^10
3 months if acute thrombosis
6 months if need anti-coag for something else
Why do we use Fondaparinux for HIT
when patients are stable and low risk of bleeding
When do we use Bivalirudin and Argatroban
ICU, dialysis, < 30 CrCl, bleeding risk, urgent procedure and life threatening thrombosis
Is Fondaparinux (Arixtra) a heparin?
NO
DVT/PE dosing for Fondaparinux
Weight < 50 kg: 5 mg SQ daily
Weight 50-100 kg: 7.5 mg SQ daily
Weight > 100 kg: 10 mg SQ daily
CLcr < 30 mL/min: CONTRAINDICATED
can we use aPPT to monitor Arixtra?
no only Anti-Xa
Why cant Arixtra be use to bridge thrombin
bc it has no effect on thrombin inhibition
What is the indication for Bivalirudin?
Alternative to Heparin in HIT
Alternative to heparin in CABG or Angioplasty
What is the indication for Argatroban
Alternative to Heparin in HIT
Bivalirudin and Argatroban aPPT range?
45-75 seconds
What is the benefit of Argatroban
hepatic elimination rather than renal
Why cant Argatroban be used to bridge warfarin
Causes PT/INR elevation
Angiomax dose
Bilvalirudin 0.15 mg/kg/hr
what type of anticoagulants are bivalirudin and Argatroban?
direct thrombin inhibitors
Argatroban dose
2 mcg/kg/min IV
Pradaxa renal dosing cut off
<30 CrCl do not use
<50 CrCl w PgP inhibitors do not use (ketoconazole, quinidine, verapamil, erythromycin, cyclosporine, amiodarone, or dronedarone)
Xeralto renal dosing cut off
<15 CrCl do not use
Eliquis renal dosing cut off
NONE
Savaysa renal dosing cut off
CLcr > 50 mL/min and after 5-10 days of parenteral therapy: Weight > 60 kg: 60 mg PO daily
For CLcr 15-50 mL/min or weight ≤ 60 kg or who use certain P-gp inhibitors1: 30 mg PO daily
CLcr < 15 mL/min:
do not use for the treatment of VTE
What is an patient education for Xeralto
take medication with an evening meal
What is an patient education for Pradaxa
use within 4 months and keep in original bottle
What is are patient educations for DOAC
Do not abruptly stop
report any prolonged bleeding or unexpected bleeding
other blood thinners will put you more at risk of a bleed out
CYP2C9 *2 and *3 require more or less warfarin
less bc it metabolizes slower
VKORC1 requires more or less warfarin
Less
Hetero 25%
Homo 50%
Starting dose of Warfarin
how much do we raise or lower warfarin
2.5 or 50% whichever is loss
what are the lowering factors for warfarin
Dose Lowering Factors
* Weight < 45 kg
* Malnourishment
* Baseline INR > 1.3
* Albumin < 3 gm/dL
* Liver disease
* Catabolic conditions (recent surgery, hyperthyroidism, ADHF, pneumonia)
* Taking azole antifungals, metronidazole, Septra, amiodaron
What are the raising factors for warfarin
Dose Raising Factors
* Weight > 90 kg
* Untreated hypothyroidism
* Receiving enteral feeds
* Taking rifampin, carbamazepine, dicloxacillin, phenobarbital, bosentan
The usual INR is 2-3 when do we raise it
mech or prostetic heart 2.5 - 3.5
Drugs that raise warfarin metabolism
Carbamazepine
Phenytoin
Phenobarbital
Rifampin / Rifabutin
St. John’s wort
Drugs that decrease warfarin metabolism
Amiodarone
Cimetidine
Ciprofloxacin
Erythromycin
Fluconazole
Fluvastatin
Ginseng
Itraconazole
Ketoconazole
Metronidazole
Trimethoprim / Sulfamethoxazole
What are the 4 toxicities with Warfarin
Bleeding
Birth defect
skin necrosis
Purple toe syndrome
What are 10 patient educations for Warfarin
M 1. Minor bleedin is common
2. only 1 alcoholic drink
3. Warfarin decreases the activity of vitamin K = longer time it takes a clot to form
4. Never skip a dose or take a double dose
5. Serious but rare major bleeding (head, stool urine or eyes)
6. check for bleeding
M 7. fall or head hit, seek medical attention
8. a lot of DDI talk to your doctor
M 9. consistent intake of vitamin K
How to bridge heparin and warfarin?
start both on day 1 till day 5 after check if INR is in range 2-3 for 2 days then stop heparin and send home
Warfarin/DOAC duration
usually 3 months unless need to be given for life
When would I give warfarin/doac for life
low bleed risk for unprovoked or pt with cancer
in a patient with cancer what anticoagulant should i give
DOAC or LWMH
warfarin not favored
when would i use a IVC filter
cant use anticoagulants
active bleed
What neutralizes LWMH and dosing
Protamine Sulfate
1 mg : 100 units over 1-3 mins
calculate half life to solve going bavk 5 Half lives
DNE 50 mg
Can you reverse the effects of Enoxaparin
1 mg protamine: 1 mg enoxaparin (if enox. given < 8 hours ago)
– 0.5 mg protamine: 1 mg enoxaparin (if enox. given > 8 hours ago)
Daily requirement of vita K
70 mcg/day
What are routes and administration and what is the preferred for vitamin K
PO but takes 24hrs for the max
SQ is erratic
IV can cause anaphylactic but fast onset (reserved for last resort)
Reversal of warfarin guidelines
when would I give Kccnetra over vitamin K
when they have a life-threatening bleed
Kccentra (4 factor prothrombin complex concentrate) dose
Rapid acting
what is the reversal agent for Dabigatran
Idarucizumab (PraxbindTM)
DOSE:2.5g/50mLIVbolusx2(totaldose=5g)
how to reverse apixaban or rivaroxaban
Andexanet alfa
