Pharm exam 1: section 3 Flashcards

Question

Hematopoetic Growth Factors | Treat anemia

Answer 1

Epoetin alfa (Epogen, EPO, Procrit) and darbepoetin alfa (Aranesp) -Stimulate erythropoiesis -Used for treatment of anemia due to end stage renal disease, AIDS or chemotherapy -Preoperatively to prepare for allogeneic transfusions ``` Granulocyte colony stimulating factor filgrastim [Neuopgen] pegfilgrastim [Neulasta] tbo-filgrastim [Granix]) Stimulates granulocyte formation ``` Use Neutropenia due to bone cancer and chemotherapy

Answer 2

Pharmacokinetics Well absorbed SubQ Metabolism and excretion not well understood ``` Precautions and contraindications Epoetin alfa & darbepoetin alfa HTN is only contraindication Increased risk of tumor growth Pregnancy Category C ``` Filgrastim & pegfilgrastim Hypersensitivity to E. coli Pregnancy Category C

Answer 3

Adverse Drug Reactions All can produce bone pain (large bones - Sternum -> feels like MI pain; femur and pelvis) Epoetin alfa & darbepoetin Seizures / HTN (don't give to HTN pts) Decreased overall survival rate and/or tumor growth in patients with certain cancers Filgrastim & pegfilgrastim Hypersensitivity Drug Interactions

Answer 4

Goal: prevent transfusion Renal pts that are transplant candidates Antibody exposure -> effects tissue typing that occurs Hgn 11-12 range Clinical Use and Dosing Epoetin alfa to treat anemia, CKD, chemo, HIV 50-150 mcg/kg 3 times a week Dose dependent on diagnosis For allogeneic transfusion: 300 mcg/kg/d given 10 days prior to surgery, day of surgery and for 4 days after surgery Darbepoetin: CKD and chemo 0.45-2.25 mcg/kg once weekly

Answer 5

Monitoring Darbepoetin alfa: Hgb weekly, ferritin periodically Epoetin alfa: Hct weekly, ferritin periodically, monitor BP cannot receive if BP is high Patient education Administration Self administration of SubQ medication Use of iron supplements Adverse drug reactions HTN and allergic reactions

Answer 6

Iron deficiency anemia Decreased iron carrying capacity of the blood Inadequate intake or blood loss (acute or chronic) Gastric bypass pt: cannot absorb enough iron Treated with iron replacement Folic Acid Deficiency Anemia Seen in alcoholics, chronic malnutrition, fad diets, and diets low in vegetables Drugs: Dilantin, sulfamethoxazole/trimethoprim, and oral contraceptives, methotrexate Pernicious anemia Vitamin B12 deficiency leads to macrocytic-normochromic anemia (large cells, normal in color) Vegetarians, vegans, genetic predisposition, autoimmune disease

Answer 7

Prevention Adequate intake via iron-rich diet (difficult w/ gastric bypass pts) Monitor in periods of rapid growth (infancy, adolescence, pregnancy): increased risk bc needs are higher Replacement in infants 1 mg/kg/day starting at 4 months (2 mg/kg/d in preterm infants) Treatment Oral vs. intravenous Oral - once daily dosing or even once every other day dosing Better GI tolerance every other day and equally efficacious

Answer 8

Monitoring - Reticulocyte count 5-10 days after starting therapy - Hgb, Hct, ferritin at 4 weeks and then at 3 months and annually Outcome evaluation Return to normal Hgb, Hct and ferritin levels If Hgb, Hct and ferritin do not return to normal levels the patient should be evaluated for a source of blood loss or other pathology * CANNOT be iron deficient if ferritin is normal and iron is low

Answer 9

Patient Education Importance of prevention with adequate iron intake in diet Administration Empty stomach if tolerated with ½ glass of orange juice Daily or every other day is best Constipation (may need a stool softener) Avoid calcium-rich foods/supplements when taking iron

Answer 10

Iron preparations build serum iron and iron storage in the body Enhanced absorption if iron stores low Ferrous form is absorbed more readily Food affects absorption - take on empty stomach Eliminated via shedding of GI mucosal cells or via bleeding

Answer 11

Precautions and Contraindications Hemochromatosis and hemolytic anemia Adverse Drug Reactions GI symptoms (constipation, GI upset) Acute toxicity possible especially in children Drug interactions Chelation (abx) Decreased absorption decreased w/ aluminum, magnesium, calcium Acid: ascorbic acid enhances absorption

Answer 12

``` Clinical use and dosing Iron deficiency anemia Adults 150-300 mg elemental iron daily Treat for 3 to 4 months after Hgb/Hct return to normal Premature infants 2-4 mg/kg/day Infants and young children 4-6 mg/kg/day ``` Monitoring Reticulocyte count 7-10 days after starting therapy Hgb at 2 weeks, then based on individual risk

Answer 13

Patient Education Prevention Adequate intake of iron in diet Administration Take on empty stomach if tolerated (w/ orange juice) Take with Vitamin C to enhance absorption Avoid taking with dairy products, calcium, antacids Adverse Reaction Constipation (stool softener, laxative) Acute iron toxicity if overdose, keep away from children

Answer 14

Risk groups Infants fed goat’s milk or powdered milk formula Vegetarians and vegans Pregnancy increases daily requirement need Patients with Celiac disease, Crohn’s disease giardial infections short bowel syndrome Drugs that affect folic acid absorption Prevention Adequate dietary intake Folic acid supplementation in pregnancy

Answer 15

Drug therapy for deficiency Oral folic acid 1mg/day for 4 to 5 weeks Hgb levels start to rise in a week Women of childbearing age and pregnant women should consume 0.4-0.8 mg/day even if not deficient Monitoring Follow Hgb/Hct in 4 weeks and then regularly Education Length of need for folic acid Indefinite folic acid tx for malnutrition ``` Side effects: skin rash irritability impaired judgement altered sleep pattern abd distention nausea ``` Serum folic level - 1mg

Answer 16

Pernicious anemia is caused by deficiency in Vitamin B12 Defective secretion of gastric intrinsic factor, which is necessary for vitamin B12 absorption Vitamin B12 malabsorption occurs in 10-30% of adults > age 50 due to reduced pepsin activity and gastric acid secretion Prevention Eat foods high vitamin B12, such as mollusks (e.g., clams), fortified breakfast cereals, liver, trout, salmon, milk, and eggs Diet cannot fix pernicious anemia

Answer 17

Oral, IM, SC and intranasal Vitamin B12 replacement Nutritional deficit: 1000 mcg/day of cyanocobalamin is given until B12 normalizes Pernicious anemia: Vitamin B12 therapy 1,000 mcg IM daily for 1 week followed by 100 to 1,000 mcg IM weekly for a month Parenteral, nasal, or oral therapy may be used once a patient’s B12 levels return to normal. Parenteral: 1,000 mcg cyanocobalamin IM monthly Nasal: 500 mcg of cyanocobalamin weekly Oral: 1,000 mcg daily (least expensive), easiest

Answer 18

``` Monitoring: Reticulocyte counts Hgb and Hct iron folic acid vitamin B12 serum levels prior to treatment, at 5 to 7 days of therapy, then frequently until the Hgb and Hct are normal ``` Monitor potassium levels Liver function tests every 2 to 4 weeks to monitor for hepatotoxicity

Answer 19

Patient Education Disease process and need for life long therapy Vitamin B12 therapy regimen Monitoring

Answer 20

Occurs due to a inflammatory disease process Older adults predisposed ``` Patients with osteomyelitis tuberculosis rheumatoid diseases hepatitis, carcinoma myeloma lymphoma leukemia at risk ``` Much less likely to respond to epoetin Treat underlying disease Patients with chronic kidney disease will respond to erythropoietin agents

Answer 21

Treatment If associated with chronic renal failure or zidovudine-treated HIV : epoetin alfa 50-100 units/kg in adults 50 units/kg in children dosed three times a week Epoetin alpha dose is titrated to keep Hgb level between 9 – 10.5g/dL Dosage is increased by 25 percent if Hgb <9 g/dL Epoetin alpha dose is decreased by 25 percent if hemoglobin approaches 12 g/dL or Hgb increases more than 1 g/dL in any 2-week period

Pharm exam 1: section 3 Flashcards

(45 cards)