Anemia drugs Flashcards
Underlying cause of anemia
Maturation defects (cytoplasmic or nuclear), Excessive destruction of RBCs (intrinsic RBC abnormalities or extrinsic mechanisms)
RBC cytoplasmic maturation defect
Lack of iron causing a decrease of RBC synthesis
RBC nuclear maturation defects (megaloblastic anemia)
Folic acid and Vitamin B12 deficiency leading to pernicious anemia (B12) or folic acid deficiency anemia
What is Erythropoiesis
The production of RBC
Example of Erythropoiesis-Stimulating Agents
Epoetin alfa
What is Epoetin alfa used for
- end stage renal disease related anemia,
- chemotherapy induced anemia
- anemia associated with zidovudine therapy
When is Epoetin alfa ineffective
Without adequate iron or bone marrow function so iron supplement are often taken
Longer acting version of Epoetin alfa
Darbepoetin
contraindication of Epoetin alfa
Any scenario where more rbc is bad like…
uncontrolled hypertension; hemoglobin levels that are above 100 mmol/L for cancer patients and 130 mmol/L for patients with kidney disease; head and neck cancers; risk of thrombosis
Adverse effects of epoetin alfa
hypertension, fever, headache, pruritus, rash, nausea, vomiting, arthralgia, and injection site reaction
What is needed to happen before iron can be absorbed
Must be converted by gastric juices
Some foods the enhance iron absorption
Orange juice
Veal
Fish
Ascorbic acid
Some foods that impair iron absorption
Eggs (but also contain iron)
Corn
Beans (but also contain iron)
Cereal products containing phytates
Example of oral iron preparations (ferrous salts)
ferrous fumarate (Femiron®), ferrous gluconate, ferrous sulphate (FeSO4)
Examples of parenteral iron preparations
iron dextran (Dexiron®, Infufer®)
iron sucrose (Venofer®)
ferric gluconate (Ferrlecit®)
Uses of iron preperation
Prevent/treat iron deficiency but also alleviated the symptoms of iron deficiency anemia. Does not treat the underlying cause and it should be corrected
Iron adverse effects
- pediatric poisoning deaths
- nausea, vomiting, diarrhea, constipation, and stomach cramps and pain
- black, tarry stools
- Liquid oral preparations temporarily discolour teeth.
- Injectable forms cause pain upon injection
Treatment of iron toxicity (symptomatic and supportive)
Suction and maintenance of airway, correct of acidosis, control of shock and dehydration with IV fluids, blood, oxygen and vasopressors
Treatment of severe iron toxicity
Deferoxamine mesylate
Iron dextran
Parenteral iron supplement that may cause anaphylactic reactions, including major orthostatic hypotension and fatal anaphylaxis
Less frequently used. Ferric gluconate and iron sucrose is used more often
How to give iron dextran
Give a test dose of 25 mg then wait an hour to see the reaction. If no reaction, give the remaining dose
Ferric gluconate
Given to replanation total iron content to those with iron deficiency anemia undergoing hemodialysis. Risk of anaphylaxis is much less than with iron dextran, and a test dose is not required
Doses of Ferric gluconate 125 mg or higher are associated with
increased adverse events, including abdominal pain, dyspnea, cramps, and itching.
Uses of folic acid
Folic acid deficiency and during pregnancy to avoid neural tube defects
