Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PR3154 > drugs (antiplt, anticoag, fibrinolytics) > Flashcards

drugs (antiplt, anticoag, fibrinolytics) Flashcards

1
Q

antiplts target

A

block plt aggregation and 1* haemostasis (step 2)

  • to prevent activation of clotting factors, fibrin formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

classes of antiplt

A

adenosine uptake, PDE3i (dipyridamole)
COX1 i (aspirin)
ADP (P2Y12) receptor i (clopi, ticag)
glycoprotein IIb/ IIIa inhibitor (eptifibatide)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

dipyridamole MOA

A
  • inhibit PLT activation and aggregative by incr cAMP within plt

1) Adenosine reuptake inhibitor
* Incr plasma adenosine
* activation of A2 receptors on PLT, incr cAMP

2) PDE3 inhibitor
* Reduce cAMP degradation within PLT, les activation of PLT

  • vasodilator
  • limite adenosine reuptake and PDEs in vascular smooth muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

dipyridamole uses

A

Adjunct antiplt in combi with others antiplt (aspirin), anticoag (warfarin)

Infused IV for myocardial perfusion imaging – good vasodilator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

dipyridamole PK

A

Dose-limiting ADR limit clinical antiplt efficacy

Fast onset after PO: 20-30mins
Peak: 2-2.5hrs
DOA: short, 3hrs (Require modified-release prep)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

ADR of dipyridamole

A

Headache, hypotension (vasodil)
Dizzy, flush, GIT disturbances, NVD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

CI, caution of dipyridamole

A
  • Hypersensitive to drug
  • Hypotension
  • severe coronary artery disease
    - Reflex tachy lead to angina pectoris, ECG abnormality, MI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

DDI of dipyridamole

A

Incr adenosine
* Incr cardiac adenosine lvls, effect

Decr cholinesterase inhibitor
* Aggravate myasthenia gravis

Bleeding
* When combined with heparin, other anticoag, antiplt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

aspirin MOA

A

Irreversible COX1 inhibitor
COX1 > COX2 inhibitor effect at lower dose

Acetylsalicylic acid blocks production of thromboxane A2 in PLT. New plt formed 7-10d

but COX2 have prostacyclin (inhibit plt aggregation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

COX action in body

A

COX 1on PLT – produce thromboxane A2
* Stimulate production of ADP, other mediators
* Promotes plt aggregation

COX 2 on endothelial cells – produce prostaglandins I2
* But PGI2 inhibit plt aggregation
* Restored by synthesis of new COX enzyme, 3-4hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

dosing of aspirin

A

OD daily more effective than 4-6hrs

  • new plt formed in 7-10d, longer lasting effect dose regiments to approach SScs
  • freq dose, incr COX2 inhibiton of PGI2, counter anti-PLT effect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

low dose of aspirin is __

A

Low dose 75-325mg loading or 40-160mg daily (OD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

indication for aspirin

A

ACS, CCS, PAD
fibrinolytic reperfusion

AIS
2nd stroke prevention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ADR of aspirin

A

1) Upper GIT (gastric ulcers, bleed)
- inhibit COX1 protective PGI in stomach (mucus secretion, blood flow, bicarbonate)

- low dose, OD will cause 2-4x incr in UGI events

2) Bruising, bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

aspirin caution

A

PLT and bleeding disorders

Combi with other antiplt, anticoag

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

P2Y12 receptor inhibitors

A

(irreversible/ reversible) prevent ADP binding

  • Blocks the ADP (P2Y12) receptor
  • Further reduce expression of (glycoprotein 2b, 2a receptor)// (a2b 3 integrin)
    = Less PLT recruitment and aggregation

loading dose regimens needed to accelerate approach to SS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

clopidogrel

A
  • Prodrug with active metabolite
    • Delayed onset (6-hr peak)
    • Interindividual variability
      ○ CYP2C19 metabolism (activation)
  • Effect on plt last 7-10d
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

clopidogrel indication and doses

A

ACS/ CCS 300-600mg LD –> 75mg OD
(6h - 2h onset)

ischaemic stroke/ TIA
300-600mg LD –> 75mg OD

PAD 75mg OD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

clopidogrel PK

A

LD: 300mg (6h), 600mg (2h)

time to plt aggregation SS w/o LD: 5-6d

M: 2 step activation (CYP3A4, IA2, 2C19)
E: t1/2: 1.9hr
50% urinary, 50% fecal

DDI: 2C19, 3A, PGP substrate

stop for surgery: 5 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

clopidogrel renal and hepatic

A

renal: no dose adj

hepatic: no dose adj, CI in severe impairment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

clop BF and preg

A

BF: no known if present, risk & benefit

preg: no assoc of ADR. discontinue 5-7d prior to labour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

clopidogrel SE

A

Haemorrhage, bleeding (intracanal bleed, bruise)

headache, dizzy, ND, C, ab pain
hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

clopidogrel CI, cautions

A
  • Hypersensitive
  • Active pathologic bleeding (Peptic ulcer)
  • At risk of bleeding
    • Intracranial haemorrhage
    • Trauma
    • Surgery
  • thrombotic thrombocytopenia purpura
  • Variant alleles of CYP2C19
    • Reduced active metabolites, less antiplt response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

CYP2C9 LoF alleles ares

A

2* or 3*
use ticagrelor instead (reduced ischemic events)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

DDI of clopidogrel

A
  • Incr risk of bleeding
    • Warfarin, aspirin, NSAIDs, salicylates, OACs
  • Reduce antiplt effect
    • Macrolides
  • Strong-mod CYP2C19i, reduce antiplt effect
    • PPI, fluoxetine, ketoconazole
  • Incr antiplt effect
    • Rifamycin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

DHI clopidogrel

incr antiplt effect

A

ginseng (antiplt)

vit E (> 400 IU/Day, antiplt)

omega 3 (>2g/day, antiplt)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

monitor for clopidogrel

A
  1. sign of bleed
  2. Hb, Hematocrit
    - DAPT: 1,3,6 mnth
    - mono: TCU
  3. PLT function
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

stop for surgery

A

min 5 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

ticagrelor MOA

A

ADP receptor P2Y12 inhibitor (reversible)

* Binds to diff site not ADP binding site
* Inhibit G protein activation and signalling

More potent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

ticagrelor dose and indication

A

180mg LD (2h)

90mg BD (12mn) –> 60mg BD (extended therapy)

CYP2C19 LoF, ACS, AIS

2nd stroke prevention (large vessel disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

ticagrelor onset

A
  • Faster onset and peak effect > clopidogrel
  • Recovery of PLT is 2-3days (depend on serum conc & active metabolites)

Faster offset too

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

ticagrelor PK

A

time to plt aggregation SS (no LD):2 days
- recovery from stopping TICA 2x rapid as Clopido

M: no biotransformation (not affected by CYP2C9, ABCB1 poly)
- hepatic CYP3A4 –> metabolite

E: parent 7h, metabolite 9h

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

stop for surgery

A

2-3day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

ticagrelor ADR

A

Haemorrhage, bleeding (intracanal bleed, bruise)

Cough, dyspnea, Bradycardia
(incr Adenosine lvl in lungs > cardiac musc)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

ticagrelor CI and cautions

A
  • Hypersensitive, SEVERE hepatic impairment, breastfeeding
  • Active pathologic bleeding
    • Peptic ulcer
  • Hist of intracranial hemorrhage
  • At risk of bleeding
    • Peptic ulcer
    • Trauma
    • Surgery
    • Elderly
    • Moderate hepatic failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

ticagrelor DDI

A
  • Incr risk of bleeding
    • Anticoag, fibrinolytics, LT NSAIDs use
      ○ Aspirin >100mg/day decr ticagrelor effect, incr bleed risk
  • CYP3A4 inducer, decr antiplt
    • Dexamethasone, phenytoin
  • CYP3A4i Incr antiplt effect
    • Clarithromycin, ketoconazole
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

glycoprotein IIb/ IIIa inhibitor (eptifibatide) MOA

A

reversible GP 2b3a receptor inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

eptifibatide indication and dose

A

ACS (PCI before use of potent antiPLT)

IV (double bolus) 180ug/kg

10min interval f/b

infusion 2ug/kg/min for 72h

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

classes of anticoagulants

A

PO :
- vit K antagonist
- DOAC (dabigatran DTI + Xa inhibitor RAE)

IV: UFH, LMWH (enoxaparin), DTI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

anticoagulants target

A

2nd hemostasis (step 3)

  • Prevent fibrinogen –> fibrin
  • Prevent polymerisation
  • Prevent activation of clotting factors, tissue factors, XIIa, Xa, IIa (thrombin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

warfarin, vit K antagonist MOA

A
  • Ext (10A)
  • Int (2A, 9)
  • Common pathway
  1. Inhibit Vit K reductase enzyme (VKORC1) that reactivate oxidized vit K
  2. Active –> inactive vit K
    • Oxidation process
    • Coupled to carboxylation of glutamic acid residues on coagulation factors II,VII,IX,X (2,7,9,10) = activation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

indication for warfarin

A

SPAF

LV thrombus
mechanicla/ prosthetic heart valves, mitral stenosis

APS

VTE/ DVT

favoured in renal, hepatic impairment (INR monitor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

warfarin initation

A

LD — hypercoagulability (prot C,S)

start with fasting anticoag, admin 5days w/ warfarin, until INR >2

monitor INR 2-3 day after change/ initiate
1) LMWH
2) UFH (if renal impair <30ml)

44
Q

warfarin doses

A

5mg OD (if not expected to be sensitive)

2.5mg (for pt expected to be sensitive)
- elderly, frail, hypoalbumin, hepatic/ renal impair, acute ill, HASBLED
- concomittant drug that decr warfarin metabolism (incr INR)
- race

45
Q

monitor warfarin for initation

A

pre-initiation:
- Base INR/ PT
- renal panel

optional: LFT, pgx

46
Q

warfarin monitoring

A

INR 2-3

higher (2.5-3.5): mitral mechanical valves

47
Q

freq of FU for monitoring

A
  • inpt: daily INR
  • after discharged from hosp: 1-3 day (unstable) 3-5d (stable)
  • outpt: 3-5d
    1wk (first mnth) –> 2wks –> 3wks –> 3mnths (v stable)
48
Q

reverse of warfarin

A

1) VITAMIN K CAN REVERSE
(PO 1-2mg –> IV 5-10mg)
- not use iV as pt can be at risk of thrombosis

2) PCC
3) fresh frozen plasma

49
Q

overcorrection

A

delayed re-anticoagulation, hard to reverse back to INR range

50
Q

PK of warfarin

A
  • PO: 24-72hrs ,rapid absorption
  • Peak: 2-8hr
  • Full effect: 5-7d
    • Need deplete endogenous vit K
  • DOA: 2-5d
    • Long t1/2 (36-42) as some coag factors II = 50hrs
  • Metabolised: 99% protein bind = hepatic, CYP2C9, 3A
    no pgp bind
  • Elimination: 20-60hrs, variable among indiv
  • excreted : urine and feces
51
Q

genetic polymorphism for warfarin metabolism in 2 genes

A

○ CYP2C9 (main metaboliser of S-warfarin)

○ vit K reductase complex subunit 1 (target MOA)

so need to monitor INR, prothrombin + titrate dose

52
Q

when to pgx

A

1) existing clot (LV thrombus)
2) outpt initiation
3) complex DDI
4) questionable adherence

benefit: =/<21mg/wk or =/>49mg/wk

NO NEED if alr know maintenance dose, no indication for dosing

53
Q

warfarin ADR

A
  • Haemorrhage/ bleeding
    • Blood ins tool, urine, melena, excess bruise, petechiae, persistent ooze from superficial injury, excess menstrual bleed
  • Hepatitis
    • > 60yr, M, warfarin < 1mnth
  • Cutaneous necrosis
    • infarction breast, buttocks, extremities
    • Reduce blood supple to adipose tissue
    • 3-5d after initiate tx
54
Q

ABSOLUTE CI for warfarin

A
  • Hypersensitive
  • Active bleed
    • Risk of pathologic bleeding
  • recent traumatic surgery of enclosed palce (eye, CNS, heart)
  • blood dyscrasias (bleed, thrombocytopenia)
  • inability to monitor tx
55
Q

relative CI of warfarin

  • link to HASBLED
A
  • mild/ mod hypertension
  • Severe renal, hepatic disease
  • Subacute bacterial endocarditis, pericarditis, pericardial effusion
  • PUD < 3mnths, chronic alcohol abuse, bariatric surgery
  • thrombophilia (deficient in prot C,S)
56
Q

cautions for warfarin

A

pts with
* Diverticulitis, colitis
* Mild, mod hypertension
* Mild, mod renal, hep disease
* Drainage tube in orifice (any)

57
Q

speical pop in warfarin

A

hepatic impairment (no specific guidelines)

renal impairment (start 10-20% lower dose, monitor INR)

breastfeeding: little risk of harm

elderly: more sensitive

preg –> LMWH: CI unless prosthetic mechanical valve

58
Q

preg absolute CI for warfarin

A

PREG
* Teratogenic 1st trimester
* 2-4 wks before delivery
* threat
* 48h postpartum
* threatened abortion, preeclampsia

exception: women with mechanical heart valve, hgih risk for thromboembolism

59
Q

DDI for warfarin

A
  • Incr bleed
    • Paracetamol LT > 2wk, high dose >2g/day
  • Risk of bleed
    • NSAID, antithrombotics, SSRI
  • CYP2C9 Inhibitors (Incr warfarin effect )
    ○ Amiodarone, isoniazide, SMX, voriconazole, metronidazole, fenofibrate, quercetin, MACROLIDES
60
Q

decr efficacy of warfarin DDI

A

Barbiturates, CS, spironolactone, thiazide diuretics

  • CYP2C9 Inducers (Decr warfarin effect)
    ○ Carbamazepine, rifampin, st John’s wort, phenobarbital
61
Q

antimicrobials effect on warfarin

A

○ Microbiome, produce menadione (type of vit K)
-Antimicrobials, decr vit K, incr INR

○ adj of warfarin
-Preemptive: SMX/TMP, ciprofloxacin, metronidazole
- No adj: macrolide, amox/calv, doxycycline

62
Q

pre-emptive dose adj of warfarin

A

(decr dose)
amiodarone
fluconazole
metronidazole
SMX-TMP, ciprofloxacin

(incr dose)
rifampin

63
Q

DFI with warfarin

○ Med, herb, suppl. Food

A

○ alcohol (rise INR, chronic decr)

○ incr INR: Gingko, ginseng, reishi mushroom, jamu, cranberry juice
○ omega-3, vit E, alcohol

○ (decr INR, decr efficacy): vit K rich foods – green tea, kale, spinach

64
Q

drug-lifestyle interaction

A

smoke: CYP450 induction, incr warfarin metabolism =(DECR INR)

incr physical activity: incr warfarin meta = (DECR INR)

65
Q

drug disease interaction

A

liver impairment (decr CF synthesis, warf meta) = INCR

infection (fever/ sepsis) (incr metabolism, clotting factor turnover faster) =INCR

hyperthyroid (incr CF turnover) = INCR

preeclmpsia (coagulability state) = DECR

HF (oedematous gut DECR) (liver, clotting factor =INCR)

renal impair (low albumin) = INCR

66
Q

DOAC - dabigatran MOA

DTI

A
  • Intrinsic pathway (2A)
  • Common pathway

Prodrug (dabigatran) are competitive reversible non-peptide antagonists of thrombin (factor IIa)

67
Q

dabigatran reversal

A

1) Reversed with Idarucizumab $1000

  • humanised Mab fragment that binds dabigatran and acyl glucuronide metabolites with greater affinity than dabi-thrombin

2) hold, renal CL or dialysis

68
Q

PK of dabigatran

A
  • PO, rapid onset, 3-7% bioavail
  • Peak action: 3h
  • T1/2: 12-17h
  • Metabolism: largely excreted unchanged (80% renally cleared)
  • Excretion: urine
69
Q

ADR of dabigatran

A

Bleeding
GIT sx (dyspepsia, discomfort)
hypotension, headache

70
Q

DDI of dabigatran

A
  • Incr risk of bleeding
    • Antiplt, anticoag, fibrinolytics, NSAID, ketoconazole
  • Decr efficacy: Rifampin
  • PGPi
71
Q

DOAC rivaroxaban MOA

A
  • Common pathway (10A)

Competitive reversible antagonist of activated factor X (Xa)

72
Q

indication and dose for rivaroxaban

A
  • DVT/ VTE
    15mg BD 21d –> 20mg OD –> proph 10mg OD
  • SPAF : 20mg OD
    crcl 30-50 = 15mg OD
    crcl 15-30 = caution
    crcl < 15 = CI

-ACS
2.5mg BD (combi w/ aspirin + clopi), continue 1 yr
crcl <3- = avoid use

73
Q

reverse rivaroxaban

A

1) Andexanet alfa
- recombinant modified human factor Xa decoy protein (NOT SG)

2) renal function to clear, hold for 1-2days

3) prothrombin complex concentrates (incr 2,7,9,10, C,S)

74
Q

PK of rivaroxaban

A
  • PO, rapid onset, 80-100% bioavail
  • Peak action: 2.5-4h
  • Half-life: 5-9h
  • Metabolism: 66% hepatic (CYP3A4, CYP2J2, PGP, BCRP)
  • Excretion: urine, faeces
75
Q

CL of rivaroxaban

A

33% –> renal excretion
33% –> renal elimination of liver metabolite
33% –> fecal elimination of liver metabolite

76
Q

special pop consideration

A

eldlery, obese (BMI >30) = no dose adj

hepatic: avoid if B & C

77
Q

preg and lact for rivaroxaban

A

preg: not recomm, (potential fetal bleed, miscarriage)

lact: risk vs benefits

78
Q

ADR of rivaroxaban

A

bleeding, bruising
gastroenteritis
vomiting
cough

79
Q

rivaroxaban DDI

A
  • Incr risk of bleeding
    • Antiplt, anticoag, NSAID, P-glycoprotein inhibitors, CYP3A4i
  • Decr efficacy
    • CYP3A4 inducers, PGP inducers
80
Q

combined P-gp and CYP3A4 inhibitors (incr bleed)

ARC

A

PO azoles (ketoconazole), ritonavir, clarithromycin (CYP3A4i, Azi P-gp inhibitor, less interaction)

81
Q

potent CYP3A4 inducers (decr efficacy):

A

carbamazepine, phenytoin, phenobarbital, rifampin, and St. John’s wort

82
Q

potent P-gp inhibitor:

A

verapamil, quinidine, dronedarone, amiodarone, macrolides (ACE), PO azole, ciclosporins.

83
Q

riva monitoring parameters

A

baseline: Hb, renal panel

efficacy: s&sx, adherence

84
Q

when to FU for DOAC

A

1mnth (first)

4mnth
* >75yo (dabi), frail

Every crcl/10 mnths
* Crcl < 60ml/min

Immediately
* Potential impact on renal, hepatic function
* Infection, NSAID use, dehydration

85
Q

compare riva with apixaban and edoxaban

A

R: OD, high BW

A: BD, low BW, elderly, CKD
SDL

E: OD
not for crcl> 95ml/min (risk of stroke)

86
Q

apixaban PK

A

F: 66%
tmax: 3h
t1/2: 8-15h
hepatic, protein bind: >80%
(CYP3A, pgp, BCRP)

87
Q

edoxaban PK

A

F: 62%
1max: 4h
t1/2: 10-14h
protein binding: ~55% (unlikely dialysable)

CYP3A, pgp

88
Q

IV anticoagulant -heparin MOA

A
  • Ext (10A)
  • Common pathway
    Potentiates action of anti-thrombin (AT III)
    Inactivates thrombin (less fibrinogen –> fibrin)
    1. Heparin bind to AT III, conformational change
    2. Expose ATIII active site with proteases
    3. Inactivates coagulation actors
      a. Thrombin, Ixa, Xa, Xia, XIIa
      b. No fibrin
89
Q

reversal for heparin

A

Protamine sulfate IV infusion
- 5kDa cationic pp
- bind to -ve heparin, neut properties

incomplete reversal for LMWH

90
Q

PK of heparin

A
  • MW: 15,000
  • Bioavail: 30%
  • T1/2: 1h
  • Excretion: liver
91
Q

ADR of heparin and LMWH

A
  • Bleeding
    ○ Anticoag effect disappear after 1hr
  • Risk epidural or spinal haematoma, paralysis
    ○ Epidural, spinal anesthesia/ puncture
  • Heparin induced thrombocytopenia
    ○ Low PLT
    ○ Drug-PLT factor 4 on activated PLT surface
    ○ IgG Ab against heparin-PF4 complex
    ○ Lower risk with LMWH
92
Q

CI for heparin & LMWH

A

OK WITH PREG, does not cross placenta, not assoc with fetal malformations

* Hypersensitive to heparin, pork
* Active major bleeding
* Thrombocytopenia, antiPLT Ab

Caution:
* Elderly pt
* Risk of bleeding
* Pt with prosthetic heart valves, major surgery, regional or lumbar block anesthesia, blood dyscrasis, recent childbirth, pericarditis effusion
* RENAL INSUFFICIENCY: LMWH

93
Q

DDI, DFI with heparin & LMWH

incr risk of bleeding

A
  • Drug
    ○ Antiplt, anticoag, fibrinolytics, NSAID, SSRIs
  • Food
    ○ Chamomile, fenugreek, garlic, ginger, gingko, ginseng
94
Q

LMWH enoxaparin MOA

A
  • Ext (10A)
  • Less int (2A)
  • Common pathway

Potentiates action of anti-thrombin (AT III)
Inactivates thrombin

More selective for factor Xa (ext, int) > factor IIa (thrombin)

95
Q

PK of LMWH

A
  • MW: 5000
  • Bioavail: 86-98%
  • T1/2: 4h
  • Excretion: renal
96
Q

enoxaparin use

A

DOC for preg, weight based dosing

bridge for warfarin
bridge for DVT

PCI

97
Q

fibrinolytic

A

Breakdown fibrin crosslinking to reverse clot stabilisaiton

(step Fibrinolysis)

98
Q

alteplase MOA

A

1) Binds preferentially to clot-associated plasminogen, –> plasmin at the clot

2) break down clots

acts like Tissue Plasminogen Activator

99
Q

alteplase PK

A

Longer plasma t1/2 than endogenous tPA
Onset of action: 20-30mins

100
Q

alteplase ADR

A

□ Haemorrhage/ bleeding

□ Ventricular arrhythmias, hypotension, oedema

□ Cholesterol embolisation, venous thromboembolism
- if break down clot too fast > gradual release
- Fragment of clots circulating = embolism

□ Hypersensitivity, anaphylaxis

101
Q

reverse alteplase

A

Tranexamic acid, aminocaproic acid

  • Compete for lysine binding sites on plasminogen and plasmin
  • Block interaction with fibrin and Reverse excess fibrinolysis
102
Q

CI of alteplase

A

Pt with active bleeding
- Prior intracranial haemorrhage
- Recent (3mnths) intracranial or intraspinal surgery
- Serious head injury
-Stroke

103
Q

caution for alteplase

A
  • Major surgery within 10d
  • risk of bleeding (peptic ulcers)
  • cerebrovascular disease, mitral stenosis, atrial fib, acute pericarditis, subacute bacterial endocarditis

◊ only use with pre-existing clot that cause imminent risk of irreversible damage or death: thrombotic stroke, or coronary embolism

◊ Prevent dislodge other clots that may be present in pt

104
Q

DDI with alteplase

A

□ Incr risk of bleeding
- Antiplt (dipyridamole, aspirin), anticoag (warfarin, heparin)
- not used within last 24hr

□ Decr alteplase lvls
- Nitroglycerin

105
Q

inclusion for thrombolytics

A

diagnosis for AIS
within 4.5hr
CT scan shows AIS diagnosis

no exclusion criteria

106
Q

exclusion criteria for thrombolytics

A

hx of ICH, IS (3mnths), subarachnoid/ intracranial haemorrhage
- endocardities, aortic arch dissection
- active internal bleeds, GI haemorrhage
- major surgery/ serious trauma in last 14d
- Lumbar puncture in last 7d
- preg

  • BP > 185/110
  • counts: INR > 1.7, PLT <100,000, glucose < 2.7
  • use of DTI, Xa inhibitor in last 48hr
  • use of warfarin in last 48hr unless INR < 1.7
  • LMWH in last 24hr

PR3154 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions