Transcript Pharmacology and the Nursing Process, 4th ed. Lilley/Harrington

Chapter 54
Anemia Drugs
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Hematopoiesis
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Formation of new blood cells
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Red blood cells (RBCs)
White blood cells (WBCs)
Platelets
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Hematopoiesis (cont’d)
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RBCs
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Manufactured in bone marrow
Immature RBCs are reticulocytes
Lifespan is 120 days
More than one third of an RBC is made of
hemoglobin
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Heme: red pigment, contains iron
Globin: protein chain
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Anemias
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Maturation defects
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Cytoplasmic
Nuclear
Excessive destruction of RBCs (hemolytic
anemias)
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Intrinsic RBC abnormalities
Extrinsic mechanisms
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Erythropoiesis Stimulating Agents
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epoetin alfa (Epogen)
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Biosynthetic form of the natural hormone
erythropoietin
Used for treatment of anemia associated with endstage renal disease, chemotherapy-induced anemia,
and for anemia associated with zidovudine therapy
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Erythropoiesis Stimulating Agents
(cont’d)
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epoetin alfa (Epogen)
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Longer acting form of epoetin called darbepoetin
(Aranesp)
Contraindications: drug allergy, uncontrolled
hypertension, head and neck cancers, risk of
thrombosis
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Classroom Response Question
Before administering epoetin alfa to a patient in
renal failure, it is most important for the nurse to
assess which laboratory result?
A. BUN
B. White blood cell count
C. Hemoglobin level
D. Urine specific gravity
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Iron
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Essential mineral in the body
Oxygen carrier in hemoglobin and myoglobin
Stored in the liver, spleen, and bone marrow
Iron deficiency results in anemia
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Iron (cont’d)
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Dietary sources: meats, certain vegetables and
grains
Dietary iron must be converted by gastric juices
before it can be absorbed
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Classroom Response Question
Which food will the nurse teach the patient to avoid
when ingesting an iron supplement?
A. Eggs
B. Veal
C. Orange juice
D. Fish
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Iron (cont’d)
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Some foods enhance iron absorption
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Orange juice
Veal
Fish
Ascorbic acid
Some foods impair iron absorption
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Eggs*
Corn
Beans*
Cereal products containing phytates
* Also common dietary sources of iron
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Iron (cont’d)
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Supplemental iron may be given as a single
drug or as part of a multivitamin preparation
Oral iron preparations are available as ferrous
salts
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ferrous fumarate (Femiron), ferrous gluconate, ferrous
sulfate (FeSO4)
Parenteral
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iron dextran (INFeD, Dexferrum)
 iron sucrose (Venofer)
 ferric gluconate (Ferrlecit)
 ferumoxytol (Feraheme)
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Iron: Indications
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Prevention and treatment of iron-deficiency
syndromes
Administration of iron alleviates the symptoms of
iron-deficiency anemia, but the underlying cause
of the anemia should be corrected
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Iron: Adverse Effects
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Most common cause of pediatric poisoning
deaths
Causes nausea, vomiting, diarrhea,
constipation, and stomach cramps and pain
Causes black, tarry stools
Liquid oral preparations may stain teeth
Injectable forms cause pain upon injection
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Iron Toxicity
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Symptomatic and supportive measures
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Suction and maintenance of the airway, correction of
acidosis, control of shock and dehydration with
intravenous fluids or blood, oxygen, and vasopressors
In patients with severe symptoms of iron
intoxication, such as coma, shock, or seizures,
chelation therapy with deferoxamine is initiated
Deferiprone is used in iron overload
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Parenteral Iron
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Iron dextran (INFeD, Dexferrum)
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May cause anaphylactic reactions, including major
orthostatic hypotension and fatal anaphylaxis
Test dose of 25 mg of iron dextran is administered
before injection of the full dose, and then remainder of
dose is given after 1 hour
Used less frequently now; replaced by newer
products ferric gluconate and iron sucrose
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Parenteral Iron
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Ferric gluconate (Ferrlecit)
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Indicated for repletion of total body iron content in
patients with iron-deficiency anemia who are
undergoing hemodialysis
Risk of anaphylaxis is much less than with iron
dextran, and a test dose is not required
Doses higher than 125 mg are associated with
increased adverse events, including abdominal pain,
dyspnea, cramps, and itching
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Classroom Response Question
The nurse has administered iron intravenously to a
patient. To prevent orthostatic hypotension, it is
recommended that the nurse have the patient
remain in the recumbent position for how long?
A. 10 minutes
B. 30 minutes
C. 60 minutes
D. 90 minutes
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Folic Acid
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Water-soluble, B-complex vitamin
Essential for erythropoiesis
Primary uses
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Folic acid deficiency
During pregnancy to prevent neural tube defects
Malabsorption syndromes are the most common
cause of deficiency
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Folic Acid (cont’d)
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Should not be used until actual cause of anemia
is determined
May mask symptoms of pernicious anemia,
which requires treatment other than folic acid
Untreated pernicious anemia progresses to
neurologic damage
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Classroom Response Question
The use of folic acid to prevent fetal neural tube
defects should be started:
A. during a woman’s adolescence.
B. at least 1 month before pregnancy.
C. when a pregnancy is first discovered.
D. at the beginning of the last trimester of
pregnancy.
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Cyanocobalamin (Vitamin B12)
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Used to treat pernicious anemia and other
megaloblastic anemias
Administered orally or intranasally to treat
vitamin B12 deficiency
Usually administered by deep intramuscular
injection
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Nursing Implications
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Assess patient history and medication history,
including drug allergies
Assess for potential contraindications
Assess baseline laboratory values, especially
Hgb, Hct, reticulocytes, others
Obtain nutritional assessment
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Nursing Implications (cont’d)
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Ferrous salts are contraindicated in patients with
ulcerative colitis, PUD, liver disease, and other
GI disorders
Keep away from children because oral forms
may look like candy
Iron dextran is contraindicated in all anemias
except for iron-deficiency anemia
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Nursing Implications (cont’d)
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For liquid iron preparations, follow
manufacturer’s guidelines on dilution and
administration
Instruct patient to take liquid iron preparations
through a straw to avoid staining tooth enamel
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Nursing Implications (cont’d)
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Oral forms of iron should be taken between
meals for maximum absorption, but may be
taken with meals if GI distress occurs
Oral forms should be given with juice, but not
with milk or antacids
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Nursing Implications (cont’d)
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Patients should remain upright for 15 to 30
minutes after oral iron doses to avoid
esophageal corrosion
Patients should be encouraged to eat foods high
in iron/folic acid
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Nursing Implications (cont’d)
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For iron dextran, a small test dose should be
given
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After 1 hour, if no reaction, the remainder of the dose
can be given
 Administer deeply into a large muscle mass using the
Z-track method
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Nursing Implications (cont’d)
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For IV doses of iron dextran, give carefully
according to manufacturer’s instructions
Have resuscitative equipment available in case
of anaphylactic reaction
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Nursing Implications (cont’d)
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Determine cause of anemia before administering
folic acid
Administer oral folic acid with food
Folic acid may also be given IV and added to
total parenteral nutrition solutions
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Nursing Implications (cont’d)
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Monitor for therapeutic responses
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Improved nutritional status
Increased weight, activity tolerance, well-being
Absence of fatigue
Monitor for adverse effects
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Classroom Response Question
Which action does the nurse perform when
administering iron intravenously?
A. Premedicate the patient with an antihistamine to
prevent anaphylaxis
B. Administer the iron with a running dextrose solution
C. Flush the intravenous line with 10 mL of normal saline
D. Have available Regitine to reverse vasoconstriction at
the site should infiltration occur
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