Pharm - Ch. 49 Drugs to Treat Anemias

After teaching a patient who is receiving ferrous sulfate about the drug therapy regimen, which patient statement indicates that the teaching was successful?

"My stools might turn dark or green." Explanation: The patient needs to know that his stools may become dark or green. Small frequent meals with snacks can help minimize nausea and GI upset associated with this drug. The patient may take the drug with meals as long as those meals do not include eggs, milk, coffee, and tea. Constipation is possible, so the patient needs to increase the fiber in his diet.

Oral Iron Preparations​

-Ferrous Fumarate (Feostat)​ -Ferrous Gluconate (Fergon)​ -Ferrous Sulfate (Feosol)​ (Prototype) -Ferrous Sulfate Exsiccated (Feratab, Slow FE)​

Folic Acid Derivatives and Vitamin B12​

-Folic acid (generic)​ -Leucovorin (generic)​ -Levoleucovorin (Fusilev)​ -Hydroxocobalamin (generic), an injectable drug​ -Cyanocobalamin (Nascobal), a nasal spray.​

Celating Agents (I will come back to)

-Heavy Metals such as, iron, lead, arsenic, mercury, copper and gold, cause toxicity in the body leading to cell death

Persons at Risk for Iron Deficiency Anemia​

-Menstruating women who lose RBCs monthly​ -Pregnant and nursing women who have increased demands for iron​ -Rapidly growing adolescents, especially those who do not have a nutritious diet​ -Persons with GI bleeding​

Erythropoietins​ (Drugs)

-Stimulate the bone marrow to make more RBC's-​ Epoetin Alfa (Epogen) ​(given sub-q) -Treats anemia associated with renal failure and AIDS, decreases need for blood transfusions in patients undergoing surgery​ Darbopoetin Alfa (Aranesp)​ -Treats anemia associated with chronic renal failure, including patients on dialysis​ Methoxy Polyethylene Glycol-Epoetin Beta (Mircera)​ -Treats anemias associated with chronic renal failure, including patients receiving dialysis​

The nurse is preparing to administer an erythropoesis-stimulating drug. The nurse checks the patient's chart, with the knowledge that the drug should not be administered to a patient with a target hemoglobin above which value?

12 g/dL Explanation: Erythropoesis-stimulating drugs should be used for patients with a target hemoglobin level of no more that 12 g/dL.

Iron Preparations (Actions, Indications and Pharmacokinetics)

Actions -Elevate the serum iron concentration​ Indications​ -Treatment of iron deficiency anemias and may also be used as adjunctive therapy in patients receiving Epoetin Alfa​ Pharmacokinetics​ -Absorbed in the small intestines​ -Transported in the blood bound to transferrin​ -Small amounts are lost daily in the sweat, urine, sloughing of skin and mucosal cell, and sloughing of intestinal cells​

Erythropoietins​ (Drugs) (cont.)

Actions​ -Acts like the natural glycoprotein erythropoietin to stimulate the production of RBC's in the bone marrow​ Indications -Treats anemia associated with chronic renal failure to reduce the need for allogenic blood transfusions in surgical patients​ Pharmacokinetics​ -Metabolized through the normal kinetic process​

Folic Acid Derivatives and Vitamin B12​ (Actions and Indications)

Actions​ -Essential for cell growth and division for the production of a strong stroma in RBCs​ -B12 is also necessary for the maintenance of the myeline sheath in nerve tissues​ Indications​ -Replacement therapy for dietary deficiencies, pregnancy​ -Folic acid is used as a rescue drug for cells exposed to some toxic chemotherapeutic agent​

Factors Essential to Producing Healthy RBCs​

Adequate Amounts of Iron​ -To form hemoglobin rings to carry the oxygen​ Minute Amounts of Vitamin B12 and Folic Acid​ -To form a supporting structure that can survive being battered through blood vessels for 120 days​ Essential Amino Acids and Carbohydrates​ -To complete the hemoglobin rings, cell membrane, and basic structure​

Iron Preparations (Adverse Effects, Drug-to-Drug Interactions)

Adverse Effects ​ -Oral - GI irritation (nausea, vomiting, constipation, diarrhea, anorexia and CNS toxicity​ leading to coma and even death with overdose -Parental iron is associated with severe anaphylactic reactions, local irritation, staining of the tissues, and phlebitis​ Drug-to-Drug Interactions​ -Antacids, tetracycline, cimetidine​ -Ciprofloxacin, norfloxacin, or ofloxacin​ -Chloramphenicol​

Folic Acid Derivatives and Vitamin B12 (Adverse Effects)

Adverse Effects ​ -Pain and discomfort at the injection site​ -Nasal irritation with intranasal spray​ Drug-to-drug interactions​ -Relatively few since they are essential​

Question: Please answer the following statement as true or false.​ ​ ​The only iron preparation designated for only parenteral use is ferrous sulfate exsiccated. ​

Answer: False​ ​Rationale: Ferrous fumarate, ferrous gluconate, ferrous sulfate, and ferrous sulfate exsiccated are available for oral administration. Iron dextran is a parenteral form of iron given by Z-track method that may be used if an oral form cannot be given or cannot be tolerated.​

Question: Please answer the following statement as true or false. ​ ​Megaloblastic anemia occurs when there is insufficient folic acid or vitamin B12 to support the stromal structure of the RBC.

Answer: True​ ​Rationale: Megaloblastic anemia equals insufficient folic acid or vitamin B12 to create the stromal structure needed in a healthy RBC. ​

Question: A 4-year-old is brought to the emergency room. The child is in shock. The mother states she found the child eating her iron-fortified vitamin pills about 2½ hours ago. The mother estimates the child ate close to 200 tablets. What medication would you expect the physician to order for the treatment iron toxicity?​ A. Deferoxamine mesylate ​ B. Methoxy polyethylene glycol-epoetin beta​ C. Sodium ferric gluconate complex​ D. Levoleucovorin​

Answer: a. Deferoxamine mesylate​ ​ Rationale: Supportive measures to deal with shock, dehydration, and gastrointestinal damage will be necessary. In addition, an iron-chelating agent such as deferoxamine mesylate may be tried.​

Nursing Considerations for patients taking Erythropoetins

Assess:​ -History and Physical Exam and known allergies​ -Severe hypertension, pregnancy, anemia and abnormal renal function​ -Patients with cancer receiving the drugs to increase hematocrit after antineoplastic chemotherapy​ -Neurological and CV status, respirations​ -Appropriate lab values​

Nursing Considerations for Folic Acid Derivatives and Vitamin B12 ​

Assess:​ -History and Physical Exam and known allergy​ -Pregnancy, lactation, and nasal erosion​ -Affect, orientation, and reflexes; pulse, blood pressure, and perfusion; respirations and adventitious sounds; and complete blood count, hematocrit, and iron levels​

Nursing Considerations for Iron Preparations​

Assess:​ History and Physical Exam and known allergy​ Colitis, enteritis, or peptic ulcer, hemolytic anemias​ Skin, neurological status, VS and CV function and BS​ Appropriate lab values​

Iron Preparations (Contraindications)

Contraindications​ -Allergy​ -Hemochromatosis​ -Hemolytic anemia​ -Normal iron balance​ -Peptic ulcer, colitis, or regional enteritis​

Erythropoietins​ (Drugs) (cont..)

Contraindications​ -Uncontrolled hypertension​ -Allergy to mammalian cell-derived​ -Allergy to human albumin​ -Lactation​ Adverse Effects ​ -CNS - Headache, fatigue, asthenia, dizziness, and seizure​ -Nausea, vomiting, and diarrhea​ -CV - Hypertension, edema, possible chest pain​

Causes of Folate and Vitamin B12 Deficiencies​

Folate Deficiencies ​ -Secondary to increased demand​ -Absorption problems in the small intestine​ -Drugs that cause folate deficiencies​ -Secondary to the malnutrition of alcoholism​ Vitamin B12 Deficiencies​ -Poor diet or increased demand​ -Lack of intrinsic factor in the stomach​

Prototype: Folic Acid

Folic Acid Indications: treatment of megaloblastic Anemia, due to sprue, nutritional deficiency Actions: Reduced form of folic acid, required for nucleoprotein synthesis and maintenance of normal erythropoiesis Route: oral, IM, IV, Sub-q. Onset varies and peak 30-60 mins Adverse effects: allergic reactions, pain and discomfort at the injection site

Prototype: Hydroxocobalamin

Hydroxocobalamin Indications: Treatment of B12 deficiency; increase B12 requirements related to disease, pregnancy or blood loss. Actions: essential for nucleic acid and protein synthesis; used for growth , cell reproduction, hematopoiesis, nucleoprotein and myelin synthesis. Route: IM, onset immediate and peak of 60 mins Adverse Effects: itching, transitory exanthema, mild diarrhea, anaphylactic reaction, HF, pulmonary edema, hypokalemia, pain at injection site

Prototype: Hydroxyurea

Hydroxyurea Indications: reduction of frequency of painful crisis and need for blood transfusions in Adult patients with sickle cell anemia Actions: increases fetal hemoglobin production in the bone marrow and dilutes the formation of abnormal hemoglobin S. Route: oral, onset varies, peak 1-4 hours, duration 18-20 hours Adverse Effects: dizziness, headache, rash, erythema, anorexia, nausea, vomiting, stomatitis, bone marrow depression and cancer.

Types of Anemia​

Iron Deficiency Anemia​ -A negative iron balance occurs​ Megaloblastic Anemia​ -Insufficient folic acid or vitamin B12 to create the stromal structure needed in a healthy RBC ​ Pernicious Anemia ​ -The gastric mucosa cannot produce intrinsic factor and vitamin B12 cannot be absorbed​

When assessing a patient with anemia, the nurse notes that the patient has developed peripheral numbness and poor coordination. The patient's family states that the patient appears to be confused at times at home. Neurologic symptoms most often accompany which type of anemia?

Pernicious anemia Explanation: Pernicious anemia is a lack of vitamin B12, which is also used by the body to maintain the myelin sheath on nerve axons. If vitamin B12 is lacking, these neurons will degenerate and cause many CNS effects.

Folic Acid Derivatives and Vitamin B12​ (Pharmacokinetics, Contraindications, Caution)

Pharmacokinetics​ -Well absorbed after injection, metabolized in the liver, and excreted in the urine​ Contraindications​ -Allergy ​ Caution​ -Pregnancy or lactation ​ -Patients with other anemias​

Blood Components

Plasma​ -The liquid part of blood; contains proteins essential for the immune response and blood clotting​ Formed Elements of the Blood ​ -Leukocytes (WBCs): Part of the immune system​ -Erythrocytes (RBCs): Carry oxygen to the tissues and remove carbon dioxide ​

A male client is prescribed interferon. What is his probable diagnosis?

Viral hepatitis Explanation: Interferons are used mainly for viral hepatitis and certain types of cancer.

A client has been diagnosed with genital warts. Which medication would the nurse anticipate being prescribed?

interferon alfa-2b Explanation: Interferon alfa-2b is approved for the treatment of genital warts (condylomata) associated with infection by human papillomavirus, non-Hodgkin's lymphoma, and malignant melanoma. P.S. - Darbepoetin alfa is another ESA used in the prevention or treatment of anemia associated with several conditions, including chronic kidney disease and myelosuppressive (depressed bone marrow function) anticancer chemotherapy.