Hematological Medications: Anemia Treatments Flashcards

Question

In what form is Folic Acid excreted?

Answer 1

1. Mostly urine | 2. A little in feces

Answer 2

The amount of iron absorbed depends partially on the body’s stores of iron. When body stores are low or RBC production is accelerated, iron absorption may increase by 20% to 30%. On the other hand, when total iron stores are large, only about 5% to 10% of iron is absorbed.

Answer 3

Enteric coated preparations decrease iron absorption because, in that form, iron isn’t released until after it leaves the duodenum. The lymphatic system absorbs the parenteral form after IM injections. Iron is transported by the blood and bound to transferrin, its carrier plasma protein. About 30% of the iron is stored primarily as hemosiderin or ferritin in the reticuloendothelial cells of the liver, spleen, and bone marrow. About 66% of the total body iron is contained in hemoglobin. Excess iron is excreted in urine, stool, and sweat and through intestinal cell sloughing. Excess iron is also secreted in breast milk.

Answer 4

Although iron has other roles, its most important role is the production of hemoglobin. About 80% of the iron in the plasma goes to the bone marrow, where it’s used for erythropoiesis (production of RBCs).

Answer 5

Oral iron therapy is used to prevent or treat iron deficiency anemia. It’s also used to prevent anemia in children ages 6 months to 2 years because this is a period of rapid growth and development.

Answer 6

A pregnant woman may need iron supplements to replace the iron used by the developing fetus. She should take oral iron therapy in the form of prenatal vitamins unless she’s unable to take iron.

Answer 7

Parenteral iron therapy is used for patients who can’t absorb oral preparations, aren’t compliant with oral therapy, or have boweldisorders (such as ulcerative colitis or Crohn’s disease). Patients with end-stage renal disease who receive hemodialysis may also receive parenteral iron therapy at the end of their dialysis session. Parenteral iron therapy corrects the iron store deficiency quickly; however, the anemia isn’t corrected any faster than it would be with oral preparations.

Answer 8

There are two parenteral iron products available. Iron dextran is given by either IM injection or slow continuous IV infusion. Iron sucrose, indicated for use in the hemodialysis patient, is administered by IV infusion.

Answer 9

Iron absorption is reduced by antacids as well as by such foods as spinach, whole-grain breads and cereals, coffee, tea, eggs, and milk products. Other drug interactions involving iron include the following: Tetracycline, demeclocycline, minocycline, oxytetracycline, doxycycline, methyldopa, quinolones, levofloxacin, norfloxacin, ofloxacin, gatifloxacin, lomefloxacin, moxifloxacin, sparfloxacin, ciprofloxacin, levothyroxine, and penicillamine absorption may be reduced when taken with oral iron preparations. Cholestyramine, cimetidine, magnesium trisilicate, and colestipol may reduce iron absorption in the GI tract. Cimetidine and other histamine-2

Answer 10

The most common adverse reaction to iron therapy is gastric irritation and constipation. Iron preparations also darken the stool. The liquid form can stain the teeth. Parenteral iron has been associated with an anaphylactoid reaction.

Answer 11

Before administering parenteral iron, be aware that it has been associated with an anaphylactoid reaction. Administer initial test doses before a fulldose infusion to evaluate for potential reactions. Continue to monitor the patient closely because delayed reactions can occur 1 to 2 days later.

Answer 12

``` arthralgia • backache • chest pain • chills • dizziness • headache • malaise • fever • myalgia • nausea • vomiting • hypotension • respiratory distress. ```

Answer 13

Assess the patient’s iron deficiency before starting therapy. • Monitor the iron’s effectiveness by evaluating the patient’shemoglobin level, hematocrit, and reticulocyte count. • Monitor the patient’s health status. • Assess for adverse reactions and drug interactions. • Observe the patient for delayed reactions from therapy. • Assess the patient’s and family’s knowledge of drug therapy.

Answer 14

Don’t give iron dextran with oral iron preparations.

Answer 15

If IM or IV injections of iron are recommended, a test dose may be required in the facility If administering iron IM, use a 19G or 20G needle that’s 2″ to 3″ long. Inject into the upper outer quadrant of the buttock. Use the Z-track method to avoid leakage into subcutaneous tissue and staining of the skin. Minimize skin staining with IM injections of iron by using a separate needle to withdraw the drug from its container. IV iron is the preferred method of parenteral administration because it results in fewer anaphylactoid reactions as well as other adverse effects. It is also used if the patient has insufficient muscle mass for deep IM injection, impaired absorption from muscle as a result of stasis or edema, the potential for uncontrolled IM bleeding from trauma (as in patients with hemophilia), or the need for massive and prolonged parenteral therapy (as in patients with chronic substantial blood loss). Promote a varied diet that’s adequate in protein, calories, minerals,and electrolytes. Encourage foods high in iron as applicable to help delay the onset of iron deficiency anemia. Administer IV fluids and electrolytes as necessary to provide nutrients. Oral food intake or tube feedings are preferable to IV therapy. Correct underlying disorders that contribute to mineral and electrolyte deficiency or excess. Promote measures to relieve anorexia, nausea, vomiting, diarrhea, pain, and other signs and symptoms Arrange for a nutritional consult as needed.

Answer 16

Patient’s hemoglobin level, hematocrit, and reticulocyte counts are normal. Patient doesn’t experience anaphylaxis. Patient and his family demonstrate an understanding of drug therapy. (See Teaching about hematinic drugs.)

Answer 17

A substance called intrinsic factor, secreted by the gastric mucosa, is needed for vitamin B12 absorption. People who have a deficiency of intrinsic factor develop a special type of anemia known as vitamin B12 -deficiency pernicious anemia. It has been the common thought that those with pernicious anemia cannot take vitamin B12 orally because they cannot absorb it; however, that is not the case. What is true is that those with vitamin B12 -deficiency pernicious anemia haveseverely impaired vitamin B12 absorption; they can be treated with oral doses of vitamin B12 but at much higher doses.

Answer 18

When cyanocobalamin is injected by the IM or subcutaneous route, it’s absorbed and binds to transcobalamin II for transport to the tissues. It’s then transported in the bloodstream to the liver, where 90% of the body’s vitamin B12 supply is stored. Although hydroxocobalamin is absorbed more slowly from the injection site, its uptake in the liver may be greater than that of cyanocobalamin.

Answer 19

With either drug, the liver slowly releases vitamin B12 as needed. It’s secreted in breast milk during lactation. About 3 to 8 mcg of vitamin B12 are excreted in bile each day and then reabsorbed in the ileum. Within 48 hours after a vitamin B12 injection, 50% to 95% of the dose is excreted unchanged in urine.

Answer 20

When vitamin B12 is administered, it replaces vitamin B12 that the body normally would absorb from the diet.

Answer 21

This vitamin is essential for cell growth and replication and for the maintenance of myelin (nerve coverings) throughout the nervous system. Vitamin B12 also may be involved in lipid and carbohydrate metabolism.

Answer 22

Cyanocobalamin and hydroxocobalamin are used to treat pernicious anemia, a megaloblastic anemia characterized by decreased gastric production of hydrochloric acid and the deficiency of intrinsic factor, a substance normally secreted by the parietal cells of the gastric mucosa that’s essential for vitamin B12 absorption.

Answer 23

Intrinsic factor deficiencies are common in patients who have undergone total or partial gastrectomies or total ileal resection. Oral vitamin B12 preparations are used to supplement nutritional deficiencies of the vitamin.

Answer 24

Alcohol, aspirin, aminosalicylic acid, neomycin, chloramphenicol, and colchicine may decrease the absorption of oral cyanocobalamin.

Answer 25

No dose-related adverse reactions occur with vitamin B12 therapy. However, some rare reactions may occur when vitamin B12 is administered parenterally

Answer 26

Adverse reactions to parenteral administration can include hypersensitivity reactions that could result in mild diarrhea, itching, transient rash, hives, hypokalemia, polycythemia vera, peripheral vascular thrombosis, heart failure, pulmonary edema, anaphylaxis, or even death.

Answer 27

Assess the patient’s vitamin B12 deficiency before therapy. • Monitor the drug’s effectiveness by evaluating the patient’s hemoglobin level, hematocrit, and reticulocyte count. • Monitor the patient’s health status. • Assess for adverse reactions and drug interactions. • Observe the patient for delayed reactions to therapy. • Assess the patient’s and family’s knowledge of drug therapy.

Answer 28

Promote a varied diet that’s adequate in protein, calories, minerals, and electrolytes. • Encourage foods high in iron as applicable to help delay the onset of iron deficiency anemia. • Administer IV fluids and electrolytes as necessary to provide nutrients. Oral food intake or tube feedings are preferable to IV therapy. • Correct underlying disorders that contribute to mineral and electrolyte deficiency or excess. • Promote measures to relieve anorexia, nausea, vomiting, diarrhea, pain, and other signs and symptoms.

Answer 29

Patient’s hemoglobin level, hematocrit, and reticulocyte counts are normal. • Patient’s underlying condition and neurologic signs and symptoms improve. • Patient and his family demonstrate an understanding of drug therapy.

Answer 30

Folic acid is an essential component for normal RBC production and growth. A deficiency in folic acid results in megaloblastic anemia and low serum and RBC folate levels.

Answer 31

Folic acid is used to treat folic acid deficiency. Patients who are pregnant or undergoing treatment for liver disease, hemolytic anemia, alcohol abuse, skin disorders, or renal disorders typically need folic acid supplementation. Folic acid supplementation also reduces the risk of neural tube defects during pregnancy and colon cancer. Serum folic acid levels less than 5 mg indicate folic acid deficiency.

Answer 32

These drug interactions may occur with folic acid:

Answer 33

Methotrexate, sulfasalazine, hormonal contraceptives, aspirin, triamterene, pentamidine, and trimethoprim reduce the effectiveness of folic acid.

Answer 34

``` Adverse reactions to folic acid include:• erythema • itching • rash • anorexia • nausea • altered sleep patterns • difficulty concentrating • irritability • overactivity. ```

Answer 35

Assess the patient’s folic acid deficiency before therapy. • Monitor the therapy’s effectiveness by evaluating the patient’s hemoglobin level, hematocrit, and reticulocyte count. • Monitor the patient’s health status. • Assess for adverse reactions and drug interactions. • Observe the patient for delayed reactions to therapy. • Assess the patient’s and family’s knowledge of drug therapy.

Answer 36

Promote a varied diet that’s adequate in protein, calories, minerals, and electrolytes. • Administer IV fluids and electrolytes as necessary to provide nutrients. Oral food intake or tube feedings are preferable to IV therapy. • Correct underlying disorders that contribute to mineral and electrolyte deficiency or excess. • Promote measures to relieve anorexia, nausea, vomiting, diarrhea, pain, and other signs and symptoms. • If using the IM route, don’t mix folic acid and other drugs in the same syringe.

Answer 37

Patient’s hemoglobin level, hematocrit, and reticulocyte counts arenormal. • Patient’s underlying condition improves. • Patient and his family demonstrate an understanding of drug therapy.

Answer 38

Erythropoietin is a substance that forms in the kidneys in response to hypoxia (reduced oxygen) and anemia. It stimulates RBC production (erythropoiesis) in the bone marrow. For the patient experiencing decreased erythropoietin production, epoetin alfa and darbepoetin alfa are glycoproteins that are used to stimulate RBC production.

Answer 39

Epoetin alfa and darbepoetin alfa may be given subcutaneously or IV.

Answer 40

After subcutaneous administration, peak serum levels of epoetin alfa occur in 5 to 24 hours. The peak level of darbepoetin alfa occurs within 24 to 72 hours. The circulating half-life is 4 to 13 hours for epoetin alfa and 49 hours for darbepoetin alfa. The therapeutic effect of these drugs lasts for several days after administration. They’re eliminated through the kidneys.

Answer 41

Patients with conditions that decrease erythropoietin production (such as chronic renal failure) typically develop normocytic anemia. Epoetin alfa and darbepoetin alfa are structurally similar to erythropoietin. Therapy with these drugs corrects normocytic anemia within 5 to 6 weeks.

Answer 42

Epoetin alfa is used to: • treat patients with anemia associated with chronic renal failure • treat anemia associated with zidovudine therapy in patients with human immunodeficiency virus infection • reduce the need for allogenic blood transfusions in patients undergoing surgery. Darbepoetin alfa is indicated for anemia associated with chronic renal failure.

Answer 43

No known drug interactions exist.

Answer 44

``` Hypertension is the most common adverse reaction to epoetin alfa and darbepoetin alfa. Other common adverse reactions may include: • headache • joint pain • nausea and vomiting • edema • fatigue• diarrhea • seizures • chest pain • skin reactions at the injection site • stroke • dizziness • deep vein thrombosis (DVT) • transient ischemic attack. ```

Answer 45

Both epoetin alfa and darbepoetin alfa increase the risk of pure redcell aplasia, myocardial infarction (MI), heart failure, stroke, cardiac arrest, and other cardiovascular events. In addition, both drugs can accelerate tumor growth and shorten lifespan in some oncology patients.

Answer 46

Assess the patient’s iron deficiency before starting therapy. • Monitor the drug’s effectiveness by evaluating the patient’s hemoglobin level, hematocrit, and reticulocyte count. • Monitor the patient’s health status. • Assess vital signs, especially blood pressure. • Assess for adverse reactions and drug interactions. • Observe the patient for delayed reactions to therapy. • Assess the patient’s and family’s knowledge of drug therapy.

Answer 47

Give the IV form of the drug by direct injection. • Additional heparin may be needed to prevent blood clotting if the patient is on dialysis. • Promote a varied diet that’s adequate in protein, calories, minerals, and electrolytes.

Answer 48

Encourage foods high in iron as applicable to help delay the onsetof iron deficiency anemia. • Administer IV fluids and electrolytes as necessary to provide nutrients. Oral food intake or tube feedings are preferable to IV therapy. • Correct underlying disorders that contribute to mineral and electrolyte deficiency or excess. • Promote measures to relieve anorexia, nausea, vomiting, diarrhea, pain, and other signs and symptoms. • Administer supplementation as necessary.

Answer 49

If hematinic drugs are prescribed, review these points with the patient and his caregivers: • The best source of minerals and electrolytes is a well-balanced diet that includes a variety of foods. • Don’t take over-the-counter preparations, other drugs, or herbal remedies without first talking to the prescriber or a pharmacist. Adverse interactions can occur with hematinic drugs. For example, herbal preparations of chamomile, feverfew, and St. John’s wort may inhibit ironabsorption. • Keep all mineral and electrolyte substances out of the reach of children; accidental overdose can occur. • Keep follow-up appointments for periodic blood tests and procedures to make sure treatment is appropriate. • Take the drug as prescribed. Iron supplements should be taken with or after meals with 8 oz (237 mL) of fluid. • Don’t crush or chew slow-release tablets or capsules. Liquid preparations can be diluted with water and sipped through a straw. • Rinse the mouth after taking liquid preparations to prevent staining of the teeth. • Iron preparations may cause dark green or black stools. • Get plenty of rest and rise slowly to avoid dizziness. Take rest periods during the day to conserve energy.