Anemia&Chemo Drugs Flashcards
Normal Hb levels of a male and female?
Male: 13.5-17.5 g/dL
Female: 12 - 16 g/dL
How is anemia defined?
Hgb < 12 g/dL
Mild anemia =
Moderate anemia =
Severe anemia =
Mild = hgb 10-12
Mod = hgb 8-12
Severe = hgb < 8
Which is a better test? Hemoglobin or hematocrit? Why?
Hemoglobin because hematocrit is sensitive to fluid shifts
Macrocytic (megaloblastic) anemia is associated with what types of deficiency?
Folic acid and B12 deficiency
Iron deficiency is d/t what 5 possible etiologies?
- Inadequate iron intake
- Inadequate iron absorption
- Increased iron demand
- Blood loss
- Chronic disease
Presentation of Anemia: Symptoms of acute onset v. chronic onset
Acute = tachycardia, light-headedness, breathlessness
Chronic = Fatigue, HA, vertigo, faintness, cold sensitivity, pallor, loss of skin tone
These symptoms can overlap
Lab values needed to diagnose anemia
CBC (WBC, Hgb, HCT, Platelets) RBC Indicies (MCV, MCHC, MCH) Reticulocyte count Peripheral blood smear Stool guiac
Normal Iron Panel levels:
- -Serum Iron
- -Serum ferritin
- -Transferrin
- -Total iron binding capacity
- -Transferrin saturation (Serum iron/TIBC)
Serum Iron = 50-160 mcg/dL
Serum ferritin = Males 30-300, Females 15-200
Transferrin = 200-360 mg/dL
TIBC = 250-400 mcg/dL
Transferrin sat = Males 20-50%, Females 15-50%
Normal folic acid levels
1.8 - 16 ng/mL
Normal vitamin B12 levels
100-900 pg/mL
Normal Erythropoietin levels
0 - 19 mu/mL
Homocysteine levels
3.3 - 10.4 umol/mL
Methylmalonic acid levels
0.07 - 0.27 umol/mL
Goals of Iron Deficient Anemia (4)
- ) Alleviate symptoms
- ) Correct iron deficiency
- ) Increase Hgb
- ) Prevent recurrence
Iron deficient lab values:
- MCV
- MCH, MCHC
- Serum ferritin
- Transferrin
- TIBC
- Transferrin saturation
Low MCV, MCH, MCHC
Low serum ferritin
High transferrin
High TIBC
Low transferrin saturation
Tx options for Iron Deficiency: Oral Iron Supplements dosage
*How much iron in mg/day is the goal?
Ferrous Sulfate
–> 300mg = 60mg elemental
Ferrous Gluconate
–> 300mg = 37mg elemental
Ferrous Fumarate
–> 100mg = 33mg elemental
Polysaccharide iron complex
–> 150mg = 100% elemental iron
What should you counsel a pt with iron deficiency on how to change their diet?
Eat meat, fish, poultry
Plant sources are more difficult for body to extract iron
How many tablets a day should one take ferrous sulfate?
5
Why? Because a 300mg tablet has 60mg elemental iron and you want a pt to consume 200mg of elemental iron/day.
So…a tablet has 20% elemental iron
When would parenteral iron be used (3 instances)
- Iron malabsorption
- Intolerant of oral therapy
- Chronic non-compliance
What is an important consideration when giving iron dextran?
Give a test dose of 25mg to assess for anaphylaxis (wait 30-60 min to assess)
Besides iron dextran, what are the other 3 parenteral iron products that are much less likely to cause anaphylaxis?
- Sodium ferric gluconate (Ferriecit)
- Iron sucrose (Venofer)
- Ferumoxytol (Feraheme)
Side effects of iron therapy
- Nausea
- Abdominal discomfort
- Constipation or diarrhea
- Black stools
How should you be monitoring iron deficiency anemia
- Weekly Hgb
- CBC
- Iron Panel
With proper iron tx you should expect to see what in the reticulocyte count?
Increase in ret count within 7 days (usually 4-5) d/t increased RBC synthesis
When treating iron how much of an increase should you expect to see weekly of Hgb
1-2 g/dL/week Hgb increase
Symptoms of Vitamin B12 Deficiency
- Typical symptoms of anemia
- Neuropsychiatric abnormalities
- Paresthesias
- Ataxia
- Memory Loss
What do the following look like in Vitamin B12 Deficiency?
- MCV
- Hgb
- Serum B12
- Schilling test
- Homocysteine
- Methylmalonic Acid
MCV = macrocytosis Hgb = low Serum B12 = low Schilling Test = assess level of intrinsic factor Homocysteine = increased Methylmalonic Acid = increased
Treatment goals of B12 Deficiency
- Resolve symptoms
- Inc. Hgb
- Prevent recurrence
First line treatment for B12 deficiency
Cyanocobalamin 1000mcg PO daily
Second line tx for B12 deficiency
Cyanocobalamin 1000mcg IM or SC daily for 1-2 weeks until acute symptoms subside
Then weekly doses of 1000mcg IM/SC x4 weeks or until Hgb/HCT are normalized
Then 1000mcg IM/SC monthly indefinitely (for life!)
When would you give Nascobal (nasal spray B12)?
Weekly for maintenance treatment of patients who have responded to oral/IM/SC vitamin B12 tx
**Must be aministered 1 hr before or after ingestion of hot foods to ensure absorption
Rare adverse effects of Vitamin B12 therapy
- Hyperuricemia
- Hypokalemia
- Sodium retention
How should the ret count and Hgb respond to vitamin B12 treatment?
Ret count = begins to increase after 2-5 days
Hgb = Should begin to rise within 1-2 weeks and normalize 1-2 months
Folic acid antagonist medications
Sulfamethoxazole/trimethoprim (Bactrim)
Methotrexate
Causes of folic acid anemia
- Increased demand
- Poor absorption from small intestine
- Alcoholism
- Use of folic acid antagonist meds
How do you distinguish between folic acid anemia and Vitamin B12 anemia?
Folic acid has normal MMA levels, no psychiatric symptoms and normal B12
Treatment of folic acid anemia
Oral folic acid 1-5 mg IV/PO daily for approx 4 months
**1mg is usually adequate
Maintenance dose of oral folic acid tx if a pt requires it
0.4 mg
Ret count and Hgb response to folic acid tx
Ret count and Hgb respond within 1-2 weeks
Should normalize within 2 months
Drugs that contribute to folic acid deficiency
- Methotrexate
- Nitrofurantoin
- Alcohol consumption
These drugs use the folic acid pathyway and therefore alter metabolism leading to reduced serum levels (3)
- Fosphenytoin
- Phenytoin
- Phenobarbital
Causes of anemia of chronic disease
- Renal failure
- Cancer
- HIV
Red Blood Cell Transfusions: disadvantages
- Limited resource
- Immunologic concerns
- Expensive (8000-1000/unit)
- Short term tx
- Infection risk
- Dated shelf life (good for only 28 days)
Types of Erythropoiesis Stimulating Agents
Darbepoetin (Aranesp) Epoetin alfa (Epogen, Procrit)
Type of ESA indicated in Cancer:
Aranesp, Epogen, Procrit
Type of ESA indicated in renal disease
Aranesp or Epogen
Type of ESA indicated in drug induced anemia:
Aranesp, Epogen, Procrit
MOA of Erythropoiesis stimulating agents
Mimic endogenous erythropoietin and circulate through the vasculature and into the bone marrow
In the bone marrow these agents bind to receptors on hematopoietic stem cells
Stimulus results in an increase in erythrogenesis (formation of new RBCs)
Is there a difference in efficacy between darbepoetin and epoetin?
No!
Darbepoetin brand names
Aranesp
Epoetin brand names
Epogen
Procrit
Which has a longer half life? Darbepoetin or Epoetin?
Darbepoetin (Aranesp)
Oncology dose of darbepoetin v. Epoetin
Darbepoetin = 500mcg q3weeks
Epoetin = 40,000 untis q/week
What is the best way to minimize the risks of ESAs
Lowest dose needed to avoid red blood cell transfusions
Max epoetin dose in oncology
60,000 units / week
Max darbepoetin dose in oncology
500 mcg q3weeks
What program should providers be enrolled in in order to give cancer patients ESAs?
APPRISE Program
Patient criteria for using ESAs
- Anemic
- Chemotherapy induced anemia or other approved indication
- Cure of cancer unlikely
Is hypertension or hypotension a side effect of ESA treatment?
Hypertension
Response to HCT or Hgb may not be seen for how long when monitoring responses to ESAs
For 2-6 weeks in renal pts
For 4-8 wks in oncology pts
___% of oncology patients respond to ESA therapy
60%
Most common type of abnormal hemoglobin
Hgb-S
Why do cells sickle?
- Cells containing Hgb-S have an impaired ability to maintain potassium and water balance
- When these cells become dehydrated the concentration of Hgb-S increases leading to molecular interactions
When do you usually start seeing symptoms of sickle cell anemia?
at 4-6 months of age when Hgb-F begins to decline
Sickle Cell anemia early sx
Pain
Swelling in hands/feet
Splenomegaly
Sickle cell anemia chronic sx
Anemia Fever Pallor Arthralgia Scleral icterus Abdominal pain Weakness Anorexia Fatigue Cardiomegaly Hepatomegaly Hematuria
Sickle Cell Crisis can be triggered by:
- Infection
- Dehydration
- Hypoxia
- Acidosis
- Sudden temp changes
Four types of Sickle Cell Crises
- Vaso-occlusive crisis (most common)
- Aplastic Crisis
- Hemolytic Crisis
- Splenic Sequestration
Complications of sickle cell disease
Acute chest syndrome
End organ damage
Goals of tx in sickle cell disease
- Dec. frequency and duration of crises
- Prevent or delay long term complications
- Improve quality of life
Supportive and preventive tx in Sickle Cell Disease
- Folic acid
- Vaccinations (H. influenzae type B and pneumococcal)
- Prophylactic PCN up to 5 years old
- -> 125 mg PO BID for < 3yrs old
- -> 250 mg BID 3-5 years old - Hydroxyurea
Treating the complications of Sickle Cell Anemia - 2 main ways
- ) RBC transfusions
- -> reserve for life-threatening situations - ) Hematopoietic Stem Cell Transplantation
- -> Only potentially curative tx
Management of Sickle Cell Anemia
- Hydration
- Pain management
- Tx infections
- RBC transfusions
- Spenectomy