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
IV iron - BWs, SEs, brand/generic names
Iron sucrose (Venofer)
Ferumoxytol (Feraheme)
Iron dextran complex (INFeD)
Boxed Warning
* Anaphylactic reactions with iron dextran and ferumoxytol - all patients receiving iron dextran should be given test dose prior to first full dose
Side Effects
* All parenteral iron products carry a risk for hypersensitivity reactions
What is the only indication for IV ferric pyrophosphate citrate (Triferic)?
- Iron replacement in patients with hemodialysis-dependent CKD
- It should be added to the bicarbonate concentrate of the hemodialysate for patients receiving hemodialysis
Pernicious anemia, the most common cause of vitamin B12 deficiency, occurs due to a lack of ____.
Fill in the blank
- Intrinsic factor (IF)
T/F: Pernicious anemia requires a lifelong parenteral vitamin B12 replacement
TRUE
What are the other causes of macrocytic anemia?
- Alcoholism
- Poor nutrition
- GI disorders (e.g., chrons disease, celiac disease)
- Pregnancy
The long term use (>= __ years) of ___, ___ or ___ can decrease the the absorption of vitamin B12.
- 2
- Metformin
- PPIs
- H2RAs
Vitamin B12 deficiency can result in serious neurologic dysfunction, including ___ neuropathies. If left undiagnosed, neurologic symptoms can become ___.
Fill in the blanks
- Peripheral
- Irreversible
Folic acid deficiency does not cause neurologic symptoms; it causes ___ of the tongue and oral mucosa and changes to skin, hair and fingernail pigmentation
Fill in the blank
- Ulcerations
T/F: Macrocytic anemia = low Hgb, high MCV
TRUE
How do you treat macrocytic anemia?
Cyanocobalamin, vitamin B12
* First-line
- IM or deep SC: 100-1,000 mcg daily/weekly/monthly
- Nascobal: 500 mcg in one nostril once weekly
Folic acid, folate, vitamin B-9
What is erythropoietin (EPO)?
- EPO is a hormone produced by kidneys that stimulates the bone marrow to produce RBCs
What happens if EPO is deficient?
- Anemia of CKD
How is anemia of CKD treated?
- Erythropoiesis-stimulating agents (ESAs) should be initiated
How do ESAs work in the body?
- ESAs help maintain Hgb levels and reduce the need for blood transfusions
- They are ineffective if iron stores are low
Epoetin alfa, Darbepoetin - brand/generic names, dosing
Epoetin alfa (Epogen, Procrit)
* CKD: 3x/week, initiate when Hgb <10 g/dL ↓ or interrupt dose when Hgb approaches or exceeds 11 g/dL (CKD on HD)
- Cancer (taking chemo): initiate when Hgb <10 g/dL
Darbepoetin (Aranesp)
* CKD: IV or SC weekly
- t1/2 is 3-fold longer than epoetin alfa (it can be given weekly)
ESAs - BWs, SEs, warnings, monitoring, storage/use
Boxed Warning
* ↑ risk of death, MI, stroke, VTE, thrombosis
- Use the lowest effective dose to reduce the need for blood tranfusions
- CKD: ↑risk of death when Hgb >11 g/dL
- Cancer: not indicated when the anticipated outcome is cure
Side Effects
* Arthralgia
Warnings
* HTN
Monitoring
* Hgb, Hct, TSAT, serum ferritin, BP
Storage/use:
* Store in the refrigerator
- Do not shake
What is the cause of hemolytic anemia?
- Acquired (e.g., drug-induced)
- Inherited (e.g., G6PD deficiency)
T/F: The direct coombs test is used for hemolytic anemia
TRUE
List drugs that can cause hemolytic anemia
- Cephalosporins
- Dapsone -
- Isoniazid
- Levodopa
- Methyldopa
- Methylene blue -
- Nitrofurantoin -
- Pegloticase -
- Penicillins
- Primaquine -
- Quinidine
- Rasburicase -
- Rifampin
- Sulfonamides -
-Avoid in G6PD deficiency
