Nutrient Deficiency Anemias Flashcards
Iron
Transported by and stored by (2)
Transported by protein Transferrin in plasma
Stored as Ferritin or as hemosiderin in macrophages (spleen, liver, bone marrow)
Vitamin B12 and Folate (Folic acid)
Both required from diet
Both necessary for DNA synthesis of RBCs (marrow) -S phase
iron def. anemia
classification
Microcytic Hypochromic Anemia
Iron Deficiency Anemia
Pathogenesis (stages) and etiology
Stage 1—progressive loss of storage iron
Stage 2—exhaustion of iron storage pool
Stage 3—frank anemia
Inadequate intake
Increased need
Impaired absorption
Chronic blood loss
iron anemia
Signs & Symptoms
iron anemia
labs
Screening tests
complete blood count (CBC)
Blood smear
Diagnostic tests
Serum iron
Total iron-binding capacity (TIBC)
Transferrin saturation
Ferritin (iron stored)
Reticulocyte count
iron anemia
Tx
- Treat underlying cause
- Oral supplementation
Ferrous sulfate oral supplements - Intravenous infusion
Infed (Iron dextran) infusion
Old standard
Injectafer (Ferric Carboxymaltose)
Ferrlecit (Sodium Ferric Gluconate Complex)
Feraheme (Ferumoxytol)
Venofer (Iron Sucrose) - RBC transfusion
Severe anemia
advangtages and disadvantages of oral vs IV iron
ferrous sulfate
MOA, Dosing, forms
MOA: Replaces iron, found in hemoglobin, myoglobin, and other enzymes
Dosing: 65mg of elemental iron daily
Previously recommended up to three times daily
Studies suggest no increased absorption with this dosing (but increased side effects)
Available as tablets or solutions
Recommend patients take with OJ and/or Vitamin C (aids in absorption)
Avoid enteric coated versions (poor absorption)
Take separately from antacids
Many medications can affect absorption
ferrous sulfate
Adverse rxns
Adverse Reactions (more common)
Nausea
Darkening of stool
Constipation
iron anemia
follow up
Measure response to treatment 3-6 months into oral treatment
CBC
Iron Studies
Reticulocyte count
Patients with intravenous iron infusions
Follow up 6-8 weeks with
CBC
Reticulocyte count
Iron dextran (infed) (IV)
dosing, indications
Dosing: Calculation based; intravenous
Indications:
Lack of response to or poor tolerability of oral iron
Poor GI absorption
Chronic kidney disease
Active inflammatory bowel disease
Cancer
Chronic or extensive blood loss
Iron dextran (infed)
Adverse Rxns
Adverse Reactions
Risk of anaphylactic reaction
Need test dose prior to first administration
Delayed (1-2 days) infusion reaction
Arthralgia, back pain, chills, dizziness, fever, headache, malaise, myalgia, nausea, and/or vomiting)
Usually subside within 3-4 days
Flushing
Pruritus
Injection site skin discoloration Arthralgia
Injectafer (Ferric Carboxymaltose)
MOA, dosing
MOA: A non-dextran formulation that allows for iron uptake (into reticuloendothelial system) without the release of free iron
IDA Dosing (used in pregnancy 2-3rd trimester):
≥ 50kg: 750mg IV weekly x 2 doses
< 50kg: 15mg/kg IV once
Injectafer (Ferric Carboxymaltose)
adverse rxns
Adverse reactions
Hypersensitivity (not common)
Hypertension (during infusion)
Hypophosphatemia
Check level before administration
Usually resolves within 3 months
Extravasation may cause permanent skin discoloration
Ferrlecit (Sodium Ferric Gluconate Complex)
MOA, indications, dosing
MOA: Supplies a source to elemental iron necessary to the function of hemoglobin, myoglobin and specific enzyme systems
Indications: IDA including hemodialysis patients (does not dialyze)
Dosing: 125mg IV infusion every 6 weeks (or with each dialysis session) for up to 8 doses
Ferrlecit (Sodium Ferric Gluconate Complex)
adverse rxns
Adverse reactions
Hypersensitivity reaction (not common)
HTN
Nausea
Injection site discoloration
Muscle cramps
Sideroblastic anemia
classification
And characterized by
Microcytic Anemia
Disorder of Hgb synthesis
Characterized by atypical nucleated RBCs
Ringed sideroblasts are present on the bone marrow aspirate smear
Helpful to know if anemia is macrocytic, normocytic, or microcytic
sideroblastic anemia
causes
Causes
Hereditary forms very rare
Manifest in childhood
Toxins: lead, copper or zinc poisoning
Drug-induced: ethanol or isoniazid
Nutritional: pyridoxine (Vitamin B6) or copper deficiency
Diseases: Rheumatoid arthritis, multiple myeloma
Sideroblastic anemia
Tx and prognosis
Tx Remove offending agent
Some pts with hereditary form will respond to pyridoxine (B6)
Prognosis variable
If think it is typical iron deficiency anemia, but the history doesn’t fit, or there has been toxin or drug exposure, or the patient has RA…then it might be sideroblastic
Sources B12 / Folate
general
Both play a critical role in DNA and RNA synthesis.Deficiencies may cause a cell to arrest in the DNA synthesis (S) phase of the cell cycle, make DNA replication errors, and/or undergo apoptotic death
B12
Fish, meat, poultry, eggs, milk, milk products, fortified breakfast cereals
Generally not present in plant foods
Takes years to become deficient
Folate (folic acid)
Vegetables (esp dark green leafy), fruits, nuts, beans, peas, seafood, eggs, dairy products, meat, poultry, and grains. Spinach, liver, asparagus, and brussels sprouts have high folate levels.
Weeks-months to become deficient
B12 binds to
intrinsic factor
B12 deficiency
causes
Vitamin B12 deficiency
- Inadequate intake
- Increased need
- Impaired absorption
Lack of intrinsic factor
-Pernicious anemia
Malabsorption
-Gastric bypass and/or bowel resection
-Pancreatic insufficiency
-Crohn Disease
-Prolonged PPI use
Inherited errors of Vitamin B12 absorption and transport
Competition for Vitamin B12
-Blind loop syndrome
-Parasites
B12 anemia
S/Sx
4 neuro
Expect the typical findings of anemia
pallor, fatigue, SOB, palpitations, glossitis etc
Neurological Findings
Ataxia
Decreased vibratory/positional sense
+ Romberg Test
Cognitive impairment (also may occur in folate deficiency)
B12 anemia
labs
Screening tests
Complete blood count (CBC) and reticulocyte count
Blood smear examination
RBC and WBC morphology
WBC manual differential
Vitamin B12 level
Folate
Methylmalonic Acid- In certain cases
megaloplastic erythropoiesis
few or no reticulocytes
howell-jolly bodies
macrocytes with pokilocytosis
hypersegmentation of neutrophils.
b12 and folate
who to test?
MCV >100 with or without anemia
Hypersegmented neutrophils on peripheral smear
Gastric bypass surgery
Unexplained neurologic symptoms/signs
Alcoholics / malnourished / elderly
Vegans, if no supplementation
Patients on metformin with new onset neuropathy
Pernicious Anemia Deficiency (B12)
Lab Features
B12 vs Folate Deficiency
Vitamin B12 Deficiency
Tx
Adults
Vitamin B12 1000mcg PO daily
2000mcg daily if poor absorption concerns
Vitamin B12 (Cyanocobalamin) 1000mcg IM inj.
Once per week until deficiency corrected, then once a month
May give up to 3-5 times per week if neurologic symptoms
Children
Vitamin B12 1000mcg PO daily x 1 week, QOD x 1 week, , twice weekly for 2 weeks, and once weekly for 3 months
Folate Deficiency
Tx
Oral folic acid 1-5mg PO daily for 4 months
B12
Tx
Cyanocobalamin (B-12) 1000mcg IM daily x 1 week
Then 1000mcg weekly x 1 month (usually once monthly x 2-3 months)
1000mcg monthly for life if specific conditions such as Pernicious Anemia
Oral high dose 1-2 mg daily (usually labeled in mcg)
As effective but less reliable than IM
Sublingual, Nasal spray and gel formulations available
