Anemia Flashcards
What is anemia?
- Anemia is a decrease in hemoglobin (Hgb) and hematocrit (Hct) concentrations below normal range for age and gender
What is Hgb and what does it do in the body?
- Hgb is an iron-rich protein found in RBCs
- Hgb’s main purpose is to carry oxygen from the lungs to the tissues
RBCs are formed in the ______ where they take up ____ and ____ before being released into the circulation as ____ , known as ____.
Fill in the blanks
- Bone marrow
- Hgb
- Iron
- Immature RBCs
- Reticulocytes
What can cause anemia?
- Nutritional deficiencies (e.g., iron, folate, vitamin B12)
- CKD
- Malignancy
What are the symptoms of anemia?
- Fatigue
- Weakness
- SOB
- Exercise intolerance
- Headache
- Dizziness
- Anorexia and/or pallor
What are symptoms of iron deficiency anemia?
- Glossitis (inflamed, sore tongue)
- Koilonychias (spoon-shaped nails)
- Pica (eating non-foods like clay/chalk)
T/F: Vitamin B12 deficiency can present with neurologic symptoms, including peripheral neuropathies
TRUE
What is used to determine the type of anemia and the possible underlying cause?
- The mean corpuscular volume (MCV); size or average volume of RBCs
What does low MCV and high MCV mean?
- Low MCV: RBCs are smaller than normal (microcytic)
- High MCV: RBCs are larger than normal (macrocytic)
What are microcytic, normocytic and macrocytic MCV values and their likely causes?
~~~
```Microcytic: MCV <80 fL
* Iron deficiency
Normocytic: MCV 80-100 fL
* Acute blood loss
- CKD
- Bone marrow failure (aplastic anemia)
- Hemolysis
Macrocytic: MCV >100 fL
* Vitamin B12
- Folate deficiency
What laboratory tests are used to further evaluate microcytic and macrocytic anemia?
- Microcytic: Iron studies
- Macrocytic: Vitamin B12 and folate levels
A reticulocyte count measures the production of RBCs and it is low in ____ due to iron, folate or B12 deficiency and with ______.
Fill in the blanks
- Untreated anemia
- Bone marrow suppression
What are common laboratory tests in anemia?
Relevant CBC Components
* Hgb
- Hct
- RBC count
- Reticulocyte count
RBC Indices
* MCV
- MCH
- Mean Corpuscular Hemoglobin Concentration (MCHC)
- Red Blood Cell Distriburion Width (RDW)
Iron Studies
* Serum iron
- Serum ferritin
- Total Iron Binding Capacity (TIBC)
- Transferrin Saturation (TSAT)
Additional Tests
* Serum folate
- Serum vitamin B12
- Methylmalonic acid
- Homocysteine
```
~~~
What are the causes of iron deficiency?
Inadequate Dietary Intake
* Iron poor diets (e.g., vegetarian, vegan)
- Malnutrition
- Disease-related (e..g., dementia, psychosis)
Blood Loss
* Acute (GI hemorrhage)
- Chronic (heavy menses, blood donations, PUD, IBD)
- Drug-induced (NSAIDs, steroids, antiplatelets, anticoagulants)
Decreased Iron Absorption
* High gastric PH (e.g., PPIs)
- GI diseases (celiac disease, IBD, gastrectomy, gastric bypass)
Increased iron Requirements
* Pregnancy
- Lactation
What are the laboratory findings for iron deficiency anemia?
- ↓ Hgb, MCV <80 fL, ↓ RBC production (low reticulocyte count)
- ↓ Serum iron, ferritin and TSAT
- ↑ TIBC
How do you treat iron deficiency?
- Iron therapy: 100-200 mg elemental iron/day *
- Take iron on an empty stomach **
- Avoid H2RAs and PPIs; seperate from antacids
- Sustained-release or enteric-coated formulations cause less GI irritation but are not recommended due to poor absorption
*One oral formulation is not better than the other if dosed appropriately based on elemental iron needs.
** 1hr before or 2 hrs after meals; can be taken with food if GI upset occurs
- Ferrous gluconate: %
- Ferrous sulfate: %
- Ferrous sulfate, dried: %
- Ferrous fumarate: %
- Carbonyl iron, polysaccharide iron complex, ferric maltol: %
Give % of elemental iron in each of the listed oral products
- 12%
- 20%
- 30%
- 33%
- 100%
What are the treatment goals in iron deficiency anemia?
- ↑ in serum Hgb by 1 g/dL every 2-3 weeks; continue treatment for 3-6 months after anemia has resolved until iron stores return to normal
Most IDA is adequately treated with ___ supplements. Parenteral iron is primarily used in ___.
Fill in the blanks
- Oral iron
- Dialysis
Ferrous sulfate/Ferrous sulfate, dried - dosing, BW, SEs
Ferrous sulfate: 325 mg (65 mg elemental iron) PO daily to TID.
Ferrous sulfate, dried: 160 mg (50 mg elemental iron) PO daily to TID.
Boxed Warning
* Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6; go to emergency department or call poison control center asap (even if asymptomatic)
Side Effects
* Constipation (dose-related)
- Dark and tarry stools
T/F: A stool softener such as docusate is recommended to prevent iron-induced constipation
TRUE
What is the antidote for iron overdose?
- Deferoxamine (Desferal)
Oral iron - DDIs
Antacids, PPIs and H2RAs ↓ iron absorption by ↑ gastric PH
* Patients should take iron 2 hours before or 4 hours after taking antacids
Iron is a polyvalent cation that can ↓ the absorption of other drugs by binding with them GI tract. Seperate administration iron with:
* Quinolone and tetracycline antibiotics - take iron 2 hrs before or 4-8 hrs after
* Bisphosphonates - take iron 60 min after oral ibandronate or 30 min after alendronate/risedronate
- Levothyroxine - seperate from iron 2-4 hrs
Vitamin C ↑ the absorption of iron. Giving iron with ascorbic acid may enhance the absorption to a minimal extent
Which patient population IV iron is restricted to? Why?
Due to the severe ADRs and the cost of therapy, IV iron is restricted to patients who are;
- CKD on hemodialysis (most common IV iron use)
- CKD receiving erythropoiesis-stimulating agent (ESAs)
- Unable to tolerate oral iron or failure of oral therapy (e.g., IBD, celiac disease, certain gastric bypass procedures, achlorhydria and H.pylori)
- Religious reasons
