Drugs Acting on the Blood Flashcards
0
Q
Name 4 categories of anemia.
A
- Microcytic
- Normocytic
- Macrocytic
- Hemolytic
1
Q
Name 4 categories of drugs that act on the blood.
A
- Anti-anemic drugs
- Colony stimulating factors
- Drugs affecting homeostasis
- Treatment of thromboembolism in cats
2
Q
Name 3 causes of microcytic anemia.
A
- Iron deficiency
- Anemia of chronic disease
- Sideroblastic anemia
3
Q
Name 3 causes of normocytic anemia.
A
- Anemia of chronic disease
- Endocrine anemia
- Bone marrow failure
4
Q
Name 3 causes of macrocytic anemia.
A
- Vitamin B12 deficiency
- Folic acid deficiency
- Myelodysplastic syndrome
5
Q
Name 7 causes of hemolytic anemia.
A
- Hemoglobinopathies
- Autoimmune
- Membrane disorder
- Drug-induced
- Metabolic abnormalities
- Glucose-6-phosphate dehydrogenase deficiency
- Infections
6
Q
T/F: All anemias are treated the same.
A
False - treatment depends on type of anemia.
7
Q
What can be seen with microcytic anemia?
A
Hypochromic anemia
8
Q
What are two possible treatments for microcytic (hypochromic) anemia?
A
- Iron preparations
- Copper preparations
9
Q
Iron deficiencies are common in what 2 species?
A
Dogs and pigs
10
Q
What is a potential complication of giving iron parenterally?
A
Formation of iron carbohydrate complexes.
11
Q
What are 3 examples of oral iron preparations?
A
- ferrous chloride
- ferrous phosphate
- ferrous sulfate
12
Q
Which form of iron administration is less irritating, parental or oral?
A
Oral, parental is more likely to be astringent.
13
Q
What is copper important for in relation to iron?
A
Copper is important for the absorption of iron.
14
Q
T/F: Copper preparations can’t be given IV.
A
True
15
Q
How is copper sulfate administered?
A
Orally
16
Q
How is copper glycinate administered?
A
SC or IM
17
Q
How does the body control its iron levels?
A
By controlling iron intake.
18
Q
T/F: Too much iron in the body can cause shock.
A
True
19
Q
How is iron dextran administered?
A
Parenterally
20
Q
What is another name for macrocytic anemia?
A
Megaloblastic anemia
21
Q
Name a treatment for macrocytic anemia and the species it is used in.
A
Cobalt in ruminants
22
Q
What 3 things can be used to treat patients with anemia due to chronic renal failure or bone marrow suppression?
A
- Erythropoeitin
- Iron
- Anabolic steroids
23
Q
How is erythropoeitin administered?
A
Parenterally
24
What are 2 treatment options for immune-mediated hemolytic anemia?
- Supportive therapy
| - Blood transfusion
25
What are some examples of anti-anemic drugs that act as immunosuppressives?
- Glucocorticoids (prednisone, prednisolone)
- Cytotoxic drugs (azathioprine, cyclophosphamide)
- Danazol
- Cyclosporin A
26
What other category of drugs are colony stimulating factors used with?
Anti-cancer drugs
27
What does Filgrastim contain?
Granulocyte colony stimulating factor (G-CSF)
28
What does Sargramostim contain?
Granulocyte-macrophage colony stimulating factor (GM-CSF)
29
How are Filgrastim and Sargramostim administered?
Parenterally
30
Which only affects neutrophils, G-CSF or GM-CSF?
G-CSF
31
At therapeutic doses, Filgrastim stimulates the progenitor of which cells?
Neutrophils only
32
Sargramostim stimulates the growth and development of which cells?
Neutrophils, eosinophils, basophils, erythrocytes, macrophages
33
What is the clinical use of colony stimulating factors?
Anticancer chemotherapy-induced neutropenia
34
What are 2 adverse effects of colony stimulating factors?
- Bone pain
| - Sargramostim also causes fever and cardiopulmonary toxicity
35
What are 2 drugs that affect hemostasis?
Hemostatics, antithrombotic drugs
36
What is the pathway of hemostatic mechanisms?
- Vascular injury
- Contraction of the injured vessel
- Primary hemostasis (platelet plug)
- Secondary hemostasis (protein plug)
- Fibrinolysis
37
What is expressed by the underlying collagen of damaged endothelial cells that attracts platelets?
von Willibrand factor
38
What are 2 types of hemostatics that affect homeostasis?
- Local hemostatics
| - Systemic hemostatics
39
What do local hemostatics treat?
External bleeding
40
What do systemic hemostatics treat?
Internal bleeding
41
What is another name for local hemostatics?
Styptics
42
What are 4 examples of types of local hemostatics?
- Vasoconstrictors
- Astringents
- Surgical
- Physiological
43
What is an example of a local hemostatic vasoconstrictor?
Epinephrine
44
What are 2 examples of astringent local hemostatics?
- Tannic acid
| - Ferric chloride
45
What are 3 examples of surgical local hemostatics?
- Oxidized cellulose
- Gelatin sponge
- Collagen
46
What are 4 examples of physiological local hemostatics?
- Thromboplastin
- Thrombin
- Fibrinogen
- Fibrin
47
Can you use physiological local hemostatics for systemic bleeding?
Why?
- No
| - May cause an embolism
48
What is an example of a local anesthetic that can be added to local hemostatics?
Benzocaine
49
What are 5 examples of types of systemic hemostatics?
- Clotting factors
- Vitamin K
- Protamine sulfate
- Aminocaproic acid
- Desmopressin
50
What is another name for Desmopressin?
DDAVP
51
What are 2 sources of clotting factors for systemic hemostatics?
- Blood transfusion
| - Fresh frozen plasma (FFP)
52
What are 3 classifications of Vitamin K?
- Vitamin K1 (phytonadione)
- Vitamin K2 (menaquinone)
- Vitamin K3 (menadione)
53
What is another name for Vitamin K1?
Phytonadione
54
What is the source for Vitamin K1?
From plant origin.
55
What is another name for Vitamin K2?
Menaquinone
56
What is the source for Vitamin K2?
Formed by bacteria in the GI tract.
57
T/F: If intestinal flora is inhibited, this can lead to a tendency to bleed.
True
58
What is another name for Vitamin K3?
Menadione
59
How is Vitamin K3 produced?
Synthetically
60
What species can you not use Vitamin K3 in?
| Why?
- Horses
| - Can cause renal failure/damage.
61
Which of the 3 Vitamin Ks are available for clinical use?
Vitamin K1 and vitamin K3
62
What is the mechanism of action for Vitamin K?
Stimulates formation of prothrombin (factor II) and factors VII, IX and X in the liver.
63
How is Vitamin K administered?
Orally or parenterally
64
Which form of administration of Vitamin K may cause hypersensitivity?
IV
65
What are 4 clinical uses of Vitamin K?
- As an antidote for warfarin poisoning.
- Treatment of spoiled sweet clover (Melilotus spp.) poisoning in cattle.
- Treatment of Vitamin K deficiency (rare).
- Combined with local hemostatics for treatment of epistaxis in dogs and horses.
66
What is Warfarin?
A rodenticide
67
How long does Warfarin take to produce an effect?
| Why?
- About a day.
| - Does not affect the current cascades.
68
What can be done for immediate treatment of Warfarin poisoning?
Transfusion
69
What 2 conditions may lead to Vitamin K deficiency?
- Liver disease
| - Long term treatment with antimicrobials
70
What is protamine sulfate used for?
A specific antidote for heparin.
71
What is protamine sulfate?
| What is its action an example of?
- A strongly basic drug that binds with acidic heparin to form a salt.
- Chemical antagonism
72
How is protamine sulfate administered?
Slowly IV
73
Can protamine sulfate be given as an overdose?
| Why?
- No
| - It has anticoagulant effect, will cause bleeding.
74
What is the mechanism of action for Aminocaproic acid?
Inhibits conversion of plasminogen to plasmin.
75
What are 3 clinical uses for aminocaproic acid?
- Treatment of hemorrhage due to hyperfibrinolysis.
- Antagonism of the fibrinolytic actions of thrombolytic agents.
- Treatment of degenerative myelopathy in German Shepherds by anti-protease activity.
76
What is the mechanism of action for Desmopressin (DDAVP)?
- Increases von Willibrand's factor levels for about 2 hours in dogs by causing releasee from endothelial cells and macrophages.
- VWF is important for adherence of platelets to an injured vessel and to platelet aggregation in addition to stabilizing factor VIII.
77
What is the most common inherited bleeding disorder in dogs?
von Willibrand disease
78
What are 3 clinical uses for Desmopressin (DDAVP)?
- Controlling bleeding in dogs with von Willibrand disease.
- During surgery in dogs with von Willibrand disease.
- In blood donor dogs with von Willibrand disease.
79
What are 3 categories of antithrombotic drugs?
- Anticoagulants
- Thrombolytic agents
- Antiplatelet drugs
80
Thrombosis is most common in what species?
Cats
81
What are 2 examples of anticoagulants?
- Heparin
| - Warfarin (coumarin)
82
Does heparin have a very short or very long half life?
Very short half life.
83
What is the mechanism of action for heparin?
- Has anticoagulant effect.
- Activates antithrombin III (ATIII) resulting in inhibition of thrombin (IIa) and activated coagulation factors IXa, Xa, XIa and XIIa in the liver.
84
Is heparin a weak or strong acid?
Strong acid
85
How is heparin administered?
| How should it not be given?
- IV
| - IM or orally
86
T/F: Heparin has a slow onset of action and long duration.
False - it has a fast onset of action and a short duration.
87
How is heparin metabolized?
Rapidly in the liver.
88
T/F: Heparin does not cross the placenta and is not excreted in milk.
True
89
What are 3 clinical uses of heparin?
- Treatment of acute thromboembolism.
- The anticoagulant of choice during pregnancy.
- Also used as anticoagulant in-vitro.
90
Can heparin be used post-natal?
Yes, since it does not cross into the milk.
91
What is the most commonly used in-vitro anticoagulant?
Heparin
92
How big of a safety margin does Heparin have?
Narrow safety margin.
93
T/F: All anticoagulants have a narrow safety margin.
True
94
What is the main toxic effect of heparin?
Bleeding
95
Can heparin cause an allergic hypersensitivity?
Yes
96
What are 3 ways to treat heparin toxicity?
- Protamine sulfate
- Blood transfusion
- Fresh frozen plasma (FFP)
97
What is the mechanism of action for warfarin?
- Inhibits vitamin K epoxide reductase.
- Depletion of reduced vitamin K.
- Inhibition of activation of the precursors of factors II, VII, IX, X.
98
How long does it usually take for bleeding due to warfarin to start?
Why?
- About 2 days.
| - That's when the first of the coagulation factors start to disappear.
99
Can you treat warfarin before clinical signs appear?
Yes
100
How is warfarin administered?
| How is it absorbed?
- Orally
| - Slow but completely
101
Does warfarin have a high bioavailability?
Yes
102
Does warfarin cross the placenta?
| Does it cross into milk?
- Yes
| - Yes
103
Does warfarin bind to albumin?
- Yes 99%
104
What is the duration of action for warfarin?
2-3 days or more.
105
T/F: Warfarin is not easily displaced from plasma proteins by other drugs.
False - it is easily displaced.
106
Is warfarin metabolized by the liver?
Yes
107
What are 2 clinical uses of warfarin?
- Prevention in thromboembolic disease (long term use)
| - Rodenticide
108
Does warfarin have a wide or narrow safety margin?
Narrow
109
What is the most important toxic effect of warfarin?
Bleeding
110
Is Warfarin teratogenic?
Yes
111
What is a specific antidote for warfarin?
Vitamin K1
112
What 2 things can also be used to treat severe warfarin toxicity?
- Whole blood
| - Fresh frozen plasma (FFP)
113
What are 5 examples of drugs that increase warfarin's response?
- Phenylbutazone/salicylates
- Heparin
- Chloramphenicol
- Sulfonamides/broad-spectrum antibiotics
- Anabolic steroids
114
How do drugs that increase the response of warfarin do so?
By displacing it from plasma proteins.
115
What is an example of drugs that decrease warfarin's response?
Enzyme inducers (ex- phenobarbital)
116
What are 4 examples of thrombolytic agents?
- Streptokinase
- Urokinase
- Tissue plasminogen activator (tPA) - alteplase
- Anistreplase
117
What activate the conversion of plasminogen to plasmin?
Thrombolytic agents
118
What causes fibrinolysis?
Plasmin
119
Which thrombolytic agent, at therapeutic doses, binds specifically to plasminogen bound to fibrin (clot-specific)?
Alteplase (tPA)
120
What is the clinical use for thrombolytic agents?
Acute thromboembolic disorders
121
Do thrombolytic agents have a narrow or wide safety margin?
Narrow
122
What 2 things must be monitored during the initial 48 hours of thrombolytic therapy?
- Hemodynamic functions
| - Vital functions
123
What are 2 side effects that can be seen with the use of thrombolytic agents?
- Bleeding
| - Allergy
124
What is an antagonist to thrombolytic agents?
Aminocaproic acid
125
In low doses, aspirin inhibits what?
Synthesis of thromboxane A2 by irreversibly inhibiting cyclooxygenase.
126
What is the main proaggregant?
Thromboxane A2 (TXA2)
127
What does the mechanism of action of aspirin result in?
Inhibition of platelet aggregation.
128
What are low doses of aspirin clinically used for?
Prevention of thrombotic disorders.
129
What is more effective, a low dose of aspirin or a large dose?
A low dose.
130
What is an Antiplatelet drug that inhibits phosphodiesterase and increases cAMP?
Dipyridamole
131
What is an antiplatelet drug that blocks GPIIb/IIIa receptors?
Abciximab
132
What is an antiplatelet drug that is antithrombin and binds to thrombin?
Lepirudin
133
What is an antiplatelet drug that inhibits ADP binding?
What species is it given to?
Not given to?
- Clopidogrel
- Cats
- Dogs
134
What are 3 agents that can be used in the treatment of acute thromboembolism in cats?
- Heparin
- Thrombolytic agents (Streptokinase)
- Vasodilators
