Transcript Approach to Hemostatic Disorder

Coagulopathy
Bundarika Suwanawiboon M.D.
Yingyong Chinthammitr M.D.
Theera Ruchutrakool M.D.
Division of Hematology
Department of Medicine
Faculty of medicine
Siriraj Hospital
Bangkok Thailand 10700
Coagulopathy
Bundarika Suwanawiboon M.D.
Yingyong Chinthammitr M.D.
Theera Ruchutrakool M.D.
Coagulopathy
Outline
 Basic of Normal Hemostasis (35 minutes)
Theera
 Clinical and Laboratory Approach to
Bundarika
Bleeding Patients (35 minutes)
 Management of Bleeding Patients
Yingyong
(35 minutes)
Question and answer (15minutes)
All
Normal Hemostasis
Normal hemostasis
 Blood vessel
 Platelet
 Coagulation factors
 Fibrinolytic system
 Natural anticoagulants
Red blood cell
Platelet
Red blood cell
Platelet
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Red blood cell
Platelet
Von Willebrand factor
Fibrin polymer
Red blood cell
Platelet
Von Willebrand factor
Fibrin polymer
Red blood cell
Platelet
Von Willebrand factor
Fibrin polymer
Normal Hemostasis
Normal hemostasis
 Blood vessel
 Platelet
 Coagulation factors
 Fibrinolytic system
 Natural anticoagulants
Normal Hemostasis
Blood vessel
 Endothelium
 Connective tissue or collagen
Normal Hemostasis
Blood vessel
 Endothelium
Thrombogenesis
 von Willebrand factor
 Tissue thromboplastin
 Endothelin
Antithrombotic Effect
 Thrombomodulin
 Platelet derived relaxing
factor (PDRF)
 Prostacyclin (PGI2)
 Tissue plasminogen
activator
Normal Hemostasis
Blood vessel
 Endothelium
 Connective tissue or collagen
Normal Hemostasis
Blood vessel
 Endothelium
 Connective tissue or collagen
 Collagen direct bind and activate platelet
 Release von Willebrand factor to bind platelet
Normal Hemostasis
Platelet
 Adhesion
 via glycoprotein (GP)
 Shape change
 from disc to ameboid form
 Release
 ADP, thromboxane A2, vWF
 Aggregation
 via glycoprotein (GP)
Normal Hemostasis
Platelet
 adhesion
 aggregation
ligand
receptor
vWF
GP Ib/IX/V
collagen
GP Ia/IIa
fibrinogen
GP IIb/IIIa
Normal Hemostasis
Platelet
Platelet plug formation and
vasoconstriction
Primary hemostatic plug formation
which is enough to stop bleeding from
small and shallow wound
Normal Hemostasis
Factor XII
HMWK/PK
Factor XI
Factor XIa
Factor IX
Factor X
Coagulation pathway
Factor IXa
Factor VIIIa
Factor VIIa
Tissue factor
Factor Xa
Factor Va
Factor X
Prothrombin
Thrombin
Fibrinogen
Fibrin
Normal Hemostasis
Factor XII
HMWK/PK
Factor XI
Factor XIa
Factor IX
Extrinsic pathway
Factor IXa
Factor VIIIa
Factor X
Intrinsic pathway
Common pathway
Factor VIIa
Tissue factor
Factor Xa
Factor Va
Factor X
Prothrombin
Thrombin
Fibrinogen
Fibrin
Normal Hemostasis
Factor XII
HMWK/PK
Factor XI
Factor XIa
Factor IX
Factor X
Coagulation pathway
Factor IXa
Factor VIIIa
Factor VIIa
Tissue factor
Factor Xa
Factor Va
Factor X
Prothrombin
Thrombin
Fibrinogen
Fibrin
Normal Hemostasis
Factor XII
HMWK/PK
Factor XI
Factor XIa
Factor IX
Factor IXa
Factor VIIIa
Factor X
Activated proteinC
Protein S
ProteinC
Natural anticoagulant
Factor VIIa
Tissue factor
Factor Xa
Factor Va
Factor X heparin
antithrombin
Prothrombin
Thrombin
Fibrinogen
Fibrin
Normal Hemostasis
Fibrinolytic system
High Molecular Weight Kininogen (HMWK)
Prekallekrein (PK)
Tissue plasminogen activator (t-PA)
F.XII
Urokinase Fibrin polymer
Plasminogen
Plasmin
Streptokinase
Fibrin degradation products
(FDP)
Normal Hemostasis
“New concept !”
Cell-based model of coagulation
Normal Hemostasis
1. Initiation
IIa
Hemostasis occurs on two surfaces:
TF- bearing cells and platelet
2. Amplification
3. Propagation
IIa
X
TF VIIa
prothrombin
thrombin
VIIa TF
thrombin
prothrombin
IXa
VIIIa
Xa Va
TF-expressing cell
IX
VIII/vWF
V
XI
Va
XIa
platelet
X
IX
XIa
IXa
VIIIa
Xa Va
Activated platelet
Hoffman M et al. Blood Coagul Fibrinolysis. 1998; 9(suppl 1): S61-S65.
X
TF VIIa
prothrombin
VIII/vWF
Xa Va
thrombin
TF-expressing cell
IX
VIIIa
VIIa TF
V
XI
prothrombin
IXa
thrombin
platelet
X
IX
XIa
IXa
VIIIa
Xa Va
Activated platelet
Hoffman M et al. Blood Coagul Fibrinolysis. 1998;9(suppl 1):S61-S65.
Va
XIa
Cell-based model “Three overlapping phases”
 Initiation phase
“TF-bearing cell to generate F.Xa, F.IXa and (little amount
of) thrombin”
 Amplification phase
“Gererate cofactor F.V and F.VIII by little amount of
thrombin from initiation phase”
 Propagation phase
“Large amount of thrombin production (burst of thrombin)
on activated platelet”
Approach to Hemostatic
Disorders:
Clinical and Laboratory Approach
Bundarika Suwanawiboon, M.D.
Division of Hematology
Department of Medicine
What is the diagnosis?
Clinical Evaluation of Bleeding Patients
“80% of correct diagnosis can be made by
history taking and physical examination.”
History Taking
Identify if the bleeding problem is due to
Local vs. systemic defect
Location: single vs. multiple sites
Severity: Spontaneous? Appropriate to trauma?
Hereditary vs. acquired disorder
Onset
Family history
Underlying disease
Medication
Primary vs. secondary hemostatic disoder
Primary Hemostasis
Secondary Hemostasis
Onset
Immediate
Delayed
Sites
Skin
Superficial
Petechiae, superficial
ecchymosis
Deep
Deep ecchymosis,
hematoma
Mucosal
Common
Rare
Others
Rare
Retroperitoneal
hematoma, hemarthrosis
Primary Hemostatic defect
Secondary Hemostatic defect
Laboratory Investigation of
Hemostatic Disorders
Assessment of Primary Hemostasis
Platelet
Complete blood count (CBC)
Bleeding time/ PFA-100
Platelet aggregation study
Blood vessel
Bleeding time
von Willebrand factor (vWF)
Bleeding time
vWF Antigen, vWF: RCO, vWF multimer, FVIII
Complete Blood Count (CBC)
Platelet number
Normal platelet count: 150,000 –400,000/uL
> 100,000/uL
Bleeding unlikely
< 20,000/uL
↑ risk for spontaneous
bleeding
Must exclude pseudothrombocytopenia
Assess for platelet morphology
Thrombocytopenia
Giant platelet
Bernard-Soulier Syndrome
Pseudothrombocytopenia
Etiology of Thrombocytopenia
Decreased Production
• Hypoproliferation
• Aplastic Anemia, Amegakaryocytic
thrombocytopenia, infection, toxins, drugs
Infiltrative marrow disease, TAR
• Ineffective Thrombopoiesis
• Megaloblastic anemia
Increased Destruction
• Immune
• Alloimmune, Autoimmune: ITP, SLE
• Non-immune
• DIC, TTP, HUS
Others
• Splenic sequestration
• Hypersplenism
• Dilutional
• Massive blood transfusion
Bleeding Time
Bleeding Time: Interpretation
Normal value* : 1-9 min
Prolonged bleeding time:
Thrombocytopenia/ anemia (Hct < 20%)
Hereditary platelet dysfunction
von Willebrand disease
Severe hypofibrinogenemia
Blood vessels disorders
Uremia
Myeloproliferative disorders
Medication: Aspirin, NSAIDs,other antiplatelet drugs
Platelet Aggregation Study
Normal Platelet Response
Arterioscler Thromb Vasc Biol 2000 20:285
Epinephrine
ADP
Collagen
Ristocetin
Arachidonic
acid
Normal
Glanzmann’s
+++
+++
+++
+++
+++
-
-
-
+++
-
+++
+++
+++
+
+*
+*
Thrombasthenia
Bernard-Soulier
-
+++
+++
++
++
-
Syndrome
Storage Pool
Disease
Aspirin
Effect
(no secondary wave)
+
++
+
von Willebrand Factor
Synthesized in endothelial cells and
megakaryocytes
Two important functions:
Carrier protein for plasma FVIII
Ligand binding to platelet GPIb receptor to
initiate platelet adhesion
Primary Hemostasis: vWF
Arterioscler Thromb Vasc Biol 2000 20:285
von Willebrand Factor Panel
vWF antigen
vWF ristocetin cofactor activity
vWF multimer analysis
FVIII level
vWD Laboratory Diagnosis
Test/Type
1
2A
2B
2N
3
↑↑
N
↑↑↑↑
N or ↑
↑↑
vWF:Ag
↓
↓
↓
↓ or N
↓ or N
↓↓↓↓
vWFR:Co
↓
↓↓↓
↓↓
↓
↓ or N
↓↓↓↓
LD-RIPA
-
-
↑
-
-
-
N
↓↓↓
↓↓↓
N but ↓
absent
BT
N or ↑
2M
FVIII
N or ↓
N or ↓ N or ↓
Multimer
N but ↓
abnormal abnormal
N but ↓
vWF Multimer Analysis
Hoffmann. 4th Ed.Hematology Basic Principles and Practice
Assessment of Secondary Hemostasis
Screening tests:
PT
aPTT
Mixing study
Additional Tests
Fibrinogen
Thrombin Time
Reptilase time
Coagulation factor
assays
D-dimer
Fibrin Degradation
Product
Euglobulin lysis time
Accurate Sample Collection is the Key
Always use 3.2% sodium citrate tube and
sent to the lab immediately.
Fill tube to the proper level.
(anticoagulant to plasma ratio = 1:9)
Modification may be required based on Hct
Sodium citrate (ml) = (100 – Hct pt) x 0.5 / 55*
* normal plasma vol.
Extrinsic Pathway
Intrinsic Pathway
XII
TF
XIIa
XI
HK/PK
HMWK
IX
IX
VIIa
XIa
XIa
VII
Tenase
IXa/
IXa
VIIIa/PL
VIIIa
XX
VIIa/TF
Xa
Xa
Ca
Ca++++
IIII
Ca
Ca++++
IIa
IIa
Va/PL
Va/PL
Fibrinogen
Fibrinogen
Common Pathway
Fibrin
Fibrin
XIIIa
X-linkedFibrin
Prothrombin Time (PT)
PT : test extrinsic and common pathway
Activated Partial Thromboplastin Time
(aPTT)
aPTT : test intrinsic and common pathway
Mixing Study
Deficiency
Correctable
Normal
coagulation
time
50%
+
Inhibitor
0%
100%
Prolonged PT or aPTT occurs when
coagulation factor < 35-40%
<35%
Uncorrectable
prolonged
coagulation
time
Interpretation of Abnormal
Coagulogram
Isolated prolonged PT
Isolated prolonaged aPTT
Prolonged PT and aPTT
Isolated prolonged PT
Mixing study
Correctable
Deficiency
Hereditary: FVII
Acquired:
Early liver impairment
Vitamin K antagonist
Vitamin K deficiency
Uncorrectable
Inhibitor
FVII (rare)
Lupus anticoagulant
Isolated prolonged aPTT
Bleeding
No bleeding
Mixing study
Mixing study
Correctable
Uncorrectable
Correctable
Uncorrectable
Deficiency
Inhibitor
Deficiency
Inhibitor
Factor VIII /vWD
Factor IX
Factor XI
Factor VIII
Factor IX
Factor XI
Heparin
Factor XII
HMWK
Prekallekrein
Factor XII
HMWK
Prekallekrein
Lupus
anticoagulant
Acquired FVIII inhibitor
Prolonged aPTT and PT
Mixing study
Correctable
- FII,FV or FX deficiency
- FV and VIII deficiency
- Liver disease
- Vitamin K antagonist
- Vitamin K deficiency
- DIC
Uncorrectable
- FII, V, or X inhibitor
- Lupus anticoagulant
- LAC + Factor inhibitor
Bleeding Disorders with
Normal PT and aPTT
Factor XIII deficiency
Dysfibrinogenemia
Mild isolated factor deficiency
a2 -antiplasmin deficiency
Elevated fibrin degradation products
Platelet disorders
Vascular disorders
Further Diagnostic Tests
Specific coagulation factor assay
Coagulation factor inhibitor assay
Lupus anticoagulant panel
Other Tests for Secondary Hemostasis
Fibrinogen
D-dimer
Fibrin(ogen) degradtion product
Thrombin time
Reptilase time
Euglobulin lysis time
Fibrinogen
Functional level (200-400 mg/dl)
↓ Fibrinogen (esp. < 100 )
DIC
Fibrinolytic therapy
Primary fibrinolytic state
Congenital afibrinogenemia
Acquired/congenital dysfibrinogenemia
↑ Fibrinogen
Inflammatory states/acute illness
May associated with shortened PT/aPTT
D-Dimer
Measured cross-linked fibrin degradation
product by plasmin
More sensitive and specific for fibrinolysis than
Fibrin(ogen) Degradatioin Product (FDP)
↑ D-dimer:
DIC
Acute thromboembolic episodes
Post-trauma or surgery
Malignancy
Fibrin(ogen) Degradation Product
↑ levels in
Primary fibrinolytic syndromes
DIC
After lytic therapy
Acute thromboembolic episodes
After injury/surgery
Thrombin Time
Thrombin Time (TT)
Assess the ability to convert fibrinogen  fibrin by
adding thrombin to plasma
Prolonged TT:
Inhibitor of thrombin: heparin, anti-thrombin antibody
Hypofibrinogenemia or dysfibrinogenemia
Inhibitor of fibrin polymerization: fibrin degradation
product, paraprotein
Euglobulin Lysis Time
Euglobulin fraction of plasma is precipitated by
acetic acid and thrombin added.
Lysis of clot is observed.
Normal : > 120 min
Shortened ELT:
DIC
Liver disease
Primary fibrinogenolysis: malignancy, e.g. prostate
carcinoma
Management of
Bleeding Patients
Yingyong Chinthammitr
27 June 2007
Objectives
• Efficient practice of replacement therapy
• Management of common bleeding
problems
Goal of replacement Rx
• Treatment of bleeding
• Prevention of bleeding before procedure
• Not treat only lab. esp. in irreversible
causes of coagulopathy
1 unit
WB = Whole blood
WB
PRC
PRP
FFP
CRP
PC
Cryo
PRC = Pack Red Cell
PRP = Platelet-rich plasma
FFP = Fresh frozen plasma
PC = Platelet concentrates
(other: apheresis PLT = 4-6 u)
CRP = Cryo-removed plasma,
FFP with cryo.-removed
Cryo. = Cryoprecipitate
(F VIII 100 u, vWF, Fibrinogen,
F XIII)
Other products
•
•
•
•
•
•
•
•
Factor concentrates : VIII, IX
Prothrombin complex concentrates (PCC)
Activated PCC (APCC)
DDAVP
Vitamin K injection
Recombinant F VIIa (novoseven)
Tranexamic acid – antifibrinolysis
Fibrin glue – two bottles: Fibrinogen & Thrombin
Recombinant Factor VIIa (NovosevenR)
EFFECTIVE+SAFE but VERY EXPENSIVE
- Hemophilia with inhibitor (alloantibody)
- Factor VIII inhibitor (autoantibody)
- Uncontrolled bleeding from coagulopathy (liver
failure)
- Uncontrolled bleeding from thrombocytopenia
- Uncontrolled bleeding from platelet dysfunction
(uremia , congenital defect)
- Severe surgical and traumatic hemorrhage
II
X
TFPI
Xa
VIIa
TF
TF
VIIa
TF
TF
VIII/vWF
Xa
IIa
Va
Platelet
V
V
Tissue factor--bearing cell
IX
IX
TF
TF
TF
VIIa
XI a
X
IXa
VIIIa
VIIIa + free vWF
Va
II
Xa
Activated
Activated
Platelet
platelet
Va Va
IIa
XI
XIa
II
X
TFPI
Xa
VIIa
TF
TF
VIIa
TF
TF
VIII/vWF
Xa
IIa
Va
Platelet
V
V
Tissue factor--bearing cell
Va
TF
TF
TF
VIIa
X
VIIIa + free vWF
II
Xa
Activated
Activated
Platelet
platelet
Va Va
IIa
XI
XIa
Fibrin Glue
- มี 2 ขวด คือ
1. Thrombin
2. Fibrinogen, F XIII (cryoprecipitate)
Thrombin
XIIIa
Fibrinogen ------------->Fibrin ------> Cross-linked
Fibrin
เติม Calcium ใน Thrombin
อาจเติม Tranexamic acid ใน Fibrinogen
ใช้ อุปกรณ์ two syringes with one air-line
Tranexamic acid
- anti-fibrinolysis
- adjunctive Rx in areas with
high fibrinolysis (Oral cavity,
GI tract, GU tract)
- Contraindication : DIC,
Thrombosis, Renal bleeding
(obstructive uropathy)
- IV : 10 mg/kg/dose q 8 h
- Oral : 25 mg/kg/dose q 8 hr
- Oral wash in dental bleeding
Bleeding
• Thrombocytopenia
• Coagulopathy
• Combined
Platelet level & Bleeding
•
•
•
•
•
> 100,000/mm3
< 100,000/mm3
< 50,000/mm3
< 10,000/mm3
< 5,000/mm3
No bleeding tendency
Bleeding time prolongation
Bleeding after trauma , surgery
Spontaneous bleeding
High risk for spontaneous CNS bleeding
Thrombocytopenia & Bleeding
•
•
•
•
•
Platelet level
Platelet function
Anemia
Local problem
Coexisting coagulopathy
Platelet transfusion
• Symptomatic Rx , not Rx cause
• Dose: 1 unit per 10 kg BW
• Indication
– Bleeding associated with thrombocytopenia
– Prophylaxis, before invasive procedure/surgery
• Contra-indication
– TTP (Thrombotic thrombocytopenic purpura)
/HUS (Hemolytic uremic syndrome), HIT
(Heparin-induced thrombocytopenia)
Prophylaxis in thrombocytopenia
Condition
Threshold
Chronic stable thrombocytopenia
<5,000 or
(underproduction e.g. aplastic anemia) No
Post-chemo stable patient
<10,000
Unstable (fever or infection or
coagulopathy or platelet dysfunction)
<20,000
Invasive procedures, surgery
<50,000
Neurosurgery, ocular Sx
<100,000
Plasma derivatives: FFP, Cryo.
• No medications added
• Return to blood bank if not use within 30 min
• Most adverse transfusion reactions occur in the
first 15 min.
• Time of transfusion – not exceed 4 hr
• Rate in adult (good cardiac condition)
: 200 - 300 mL/hr
• NOT for: volume expansion, protein (alb, glob)
nutrient
Cirrhosis
• FFP 10-15 ml/kg
• Vitamin K 10 mg IV
• Pitfalls
– Uncorrected localized bleeding problem e.g. varice,
mucosal lesion
– Overdependence on PT
– Goal: to correct or prevent bleeding, Not to achieve a
normal PT
– Timing of FFP therapy before an invasive procedure
Vitamin K deficiency
- Vitamin K : fat-soluble vitamin
- Vitamin K-dependent factors :
II,VII,IX,X ; Protein C,S,Z
- Vit.K : K1(green vegetables), K2(gut
flora), K3(synthetic water-soluble)
Vitamin K deficiency
* Neonatal : hemorrhagic disease of the
newborn
* Children & Adult :
- low intake
- absorption defect - cholestasis, fat
malabsorption syndrome
- broad-spectrum antibiotics (+low intake)
Vitamin K deficiency
• Vit. K 10 mg IV slowly, sc
• FFP
• Prothrombin complex concentrate (PCC)
HEMARTHROSIS AND HEMOPHILIC ARTHROPATHY
Hemophilia A
• Cryoprecipitate
• Factor VIII concentrates
• FFP
• DDAVP
vWD
• DDAVP
• Cryoprecipitate
• F VIII concentrates
• FFP
Hemophilia B
• FFP
• Cryo. Removed Plasma
• F IX concentrates
Rx of Bleeding episodes
in Hemophilia
Site
Level (%)
Rx Length
Joint
30-40
1 dose
Muscle
30-40
1-3 doses
Hematuria
30-40
1 dose
Retroperitoneal
50
5-7 d
GI
50
5-7 d
Neck
100
7-10 d
Intracranial
100
10-14 d
Hemophilia A with hemarthrosis
•
•
•
•
60 kg.
Raise F VIII to 30 %
1 u/kg raise 2%
F VIII half life = 12 hr
– Raise 30% -> 15 u/kg = 15x60 = 900 u
– Cryo. 9 bags ( cont. ~5 bags q 12 hr)
Hemophilia B with hemarthrosis
•
•
•
•
60 kg.
Raise F IX to 30 %
1 u/kg raise 1%
F IX half life = 24 hr
– Raise 30% -> 30 u/kg = 30x60 = 1800 u
– FFP 1800 ml. ( cont. 900 ml. q 24 hr)
Warfarin-associated
coagulopathy & bleeding
• Life-threatening Bleeding
– withhold warfarin, FFP/PCCs, vit. K 5-10 mg.
i.v., provide medical support (e.g. PRC)
• Major, non-life-threatening Bleeding
– withhold warfarin, FFP/PCCs, vit. K 1-10 mg.
i.v., provide medical support (e.g. PRC)
J Thromb Haemost 2006;4:1853-63
Warfarin-associated
coagulopathy & No bleeding
INR 4.5-10
– Withhold warfarin – Withhold
warfarin
– Vit. K 1 mg.
– Reintroduce at a – Recheck INR
in 24-48 hr
lower dose on the
following day
– Recheck INR in
< 72 hr
INR >10
– Withhold warfarin
– Vit. K 1 mg. i.v.
– Recheck INR in 24
hr
Identify and correct the cause of elevated INR
Beware of re-thrombosis from overcorrection
J Thromb Haemost 2006;4:1853-63
Heparin
• Unfractionated heparin (prolonged APTT)
– Bleeding: hold heparin, protamine (1 mg/100
u heparin)
– No bleeding: hold heparin (Hf. life 1 hr)
• LMWH (normal APTT)
– Bleeding: protamine (neutralize all anti-IIa but
75% of anti-Xa)
DIC
• Rx cause
• Bleeding
– FFP , PLT concentrate
– Cryoprecipitate raise fibrinogen > 100 mg/dL
:1 bag/5 kg BW raise fibrinogen 100 mg/dL
Treatment of DIC
* Treat associated disease
* Bleeding - Replacement therapy
* Thrombosis - heparin : purpura fulminans,
acral/dermal ischemia, retained dead fetus
syndrome, giant hemangioma, aortic
aneurysm without rupture, solid tumor
* AT concentrate, APC
Massive blood transfusion
• > Total blood volume in 24 hour
• Dilution and/or consumption of PLT, Coag.
Factors
• LAB: platelet, coagulogram, fibrinogen
• PLT > 50,000, PT <1.5 times the midpoint
of normal range, Fibrinogen >100 mg/dL
: generally adequate for hemostasis
Platelet dysfunction
• Stop Antiplatelet agents before surgery
– Aspirin : 7 days (irreversible inhibition)
– NSAID : 1-4 days (reversible inhibition)
– Clopidogrel : 10 days
Uremic bleeding
Treatment Regimen
Onset
*PRC /LPB Hct ~30%
1h
*EPO
50-100 U/kg Hct 30%
(~6 wk)
*Cryoppt.
10 units
1h
*DDAVP 0.3-0.4 mcg/kg 1 h
IV or SC
2-3 mcg/kg intranasal
Duration
While Hct at this level
Same
*Conjugated 0.6 mkd IV
estrogen
50 mkd po
x 5 days
*Dialysis
14 d (IV)
5 d (PO)
6h
2d
24–36 h[Effective ~ 50%]
4–8h
Thank you for your attention
Question…