Drug Therapy as a Cause and Treatment of Anemia

Question 1

2 groups of anemia based on pathogenesis approach

Answer 1

Increased destruction or loss of RBCs

Reduced production of RBCs

Question 2

5 symptoms of anemia

Answer 2

Tired
Fatigue
Pallor
Increased HR
SOB

Question 3

3 symptoms of hemolysis

Answer 3

Jaundice
Enlarged spleen
Urine looks dark

Question 4

Function of the glucose-6-phosphate dehydrogenase enzyme

Answer 4

Reduces NADP to NADPH
NADPH is required for the production of reduced glutathione
Protects Hb and RBC membrane from oxidant stress

Question 5

What are some things that can cause hemolysis in a G-6PD deficiency (oxidative stress hemolysis)

Answer 5

Medications (antimalarials, analgesics, antibacterial/helminths)
Infections or acute illness
Fava beans
Mothballs

Question 6

Cardinal features based on history and PE for G-6PD

Answer 6

Typically male (x-linked)
Background (west africa, mediterranean, middle eats, SE Asia)
Family history
Precipitating factor
Symptoms of hemolysis

Question 7

Lab evidence for G-6PD oxidative stress hemolysis

Answer 7

CBC with normocytic anemia
Morphologic evidence of hemolysis on PBS (bite cells, blister cells, polychromasia)
Screening test and/or enzyme assay for G6PD test

Question 8

In G6PD anemia, is 
1. Bilirubin total and unconjugated
2. LDH
3. Haptoglobin
4. Reticulocyte count
5. DAT
increased or decreased

Answer 8

1. Increased
2. Increased
3. Decreased
4. Increased
5. Negative

Question 9

Microangiopathic hemolytic anemia

Answer 9

Despite thrombocytopenia, this is a prothrombotic state (drugs can cause it)
Thrombi form in the microvasculature
As blood flows through the microvasculature, the RBCs get sheared and form schistocytes
Causes hemolytic anemia

Question 10

Is drug induced immune hemolytic anemia intra or extravascular?

Answer 10

Extravascular hemolysis

Question 11

If you see high retics, what does that tell you about the bone marrow?

Answer 11

Bone marrow is working!

RBC production is ok

Question 12

Warfarin MOA

Answer 12

Vitamin K antagonist
Vitamin K is an essential cofactor in a liver enzyme
So no vitamin K = decreased vitamin K dependent clotting factors

Question 13

Vitamin K dependent coagulation factors

Answer 13

Factors 2, 7, 9, 10
Protein C
Protein S

Question 14

Heparin MOA

Answer 14

Activates antithrombin which then forms complexes with activated coagulation factors
Inactivation of those coag factors inhibits clot formation

Question 15

Advantages of older anticoags (warfarin and heparin)

Answer 15

Can monitor therapy via lab tests
Long term experience with the drugs
Readily available reversal agents

Question 16

DOACs can work in what 2 ways

Answer 16

Direct thrombin inhibitors (dabigatran)

Direct factor 10a inhibitors (rivaroxaban, apixaban)

Question 17

Advantages of the newer anticoags

Answer 17

Ease of administration (oral)
No lab monitoring required
Minimal food and drug interactions compared to warfarin
Same bleeding risk as warfarin

Question 18

Dabigatran reversal

Answer 18

Idacaruzimab = praxbind
Monoclonal antibody fragment
Binds free and thrombin bound dabigatran and neutralizes its activity

Question 19

2 indications to reverse warfarin

Answer 19

Exhibiting major bleeding manifestations
Requiring urgent (<6 hours) surgical procedures

Question 20

2 ways to give
1. Iron
2. B12
supplements

Answer 20

1. Oral, IV

2. Oral, IM

Question 21

When should you consider IV iron?

Answer 21

Complete GI intolerance of oral Fe
Very severe Fe deficiency anemia
Hemodialysis patients on erythropoiesis stimulating agents

Question 22

Pernicious anemia

Answer 22

Common cause of B12 deficiency

Caused by an autoimmune mediated impairment of B12 absorption (attacking the parietal cells that make IF)

Question 23

What should you also check for before supplementing folate?

Answer 23

Check for and treat coexisting B12 deficiency
Folic acid can improve the anemia and mask B12 deficiency
But the neurologic damage from untreated B12 deficiency can continue

Question 24

2 erythropoiesis stimulating agents

Answer 24

Erythropoietin

Darbepoetin

Question 25

What is the most common/important time to use and erythropoiesis stimulating agent

Answer 25

Chronic kidney disease