[04.14] Hematopoietics and Hematinics_ Rational Blood Use V2.pdf

Agents that increases red cells; Medicines that increase the production of blood

What are Hematinics?

Oxygen-rich carrying molecules; Important in the production of red blood cells

Iron is an important part of what molecules?

Heme (protoporphyrin ring) and globin (protein)

What are the two main components of hemoglobin?

Coordination compound

Iron is what type of compound found in the middle of globin chains together with the heme part of hemoglobin?

Carries oxygen

What is the general function of hemoglobin?

Myoglobin

What iron-containing protein is found in muscle tissue and is responsible for the red color of muscles?

Red meat

What is cited as the biggest source of iron in the diet?

Phytates

What substances found in green, leafy vegetables inhibit iron absorption?

Dirt/mud

What unusual source is mentioned as being rich in iron that often accompanies vegetables?

Recycled Iron

Where does the body get most of the iron it needs if only 1-2 mg are absorbed daily?

Around 10-20 mg

How much iron does the daily diet consist of, approximately?

Around 1-2 mg

How much iron do we absorb per day?

Desquamation of epithelium (nagbabalat)

What common daily process accounts for the loss of around 1-2 mg of iron per day?

Old or senescent red blood cells

What specific cells are destroyed in the spleen and sequestered by macrophages to recycle iron?

75%

What percentage of the iron in the body is used for erythropoiesis (red blood cell production)?

Erythropoiesis

What is the process of red blood cell production, which accounts for 75% of body iron use?

Ferritin

What is the storage form of iron (representing 10-20% of the body's iron)?

Bleeding

What is the only physiologic excretion mechanism for iron?

Bleeding (most likely)

What is the most likely cause of acquired iron deficiency?

Hemosiderin

What form is iron sometimes deposited as in tissues?

Labile pool

What contains iron that is being transported or exchanged?

Duodenum

In which specific part of the gastrointestinal tract is iron absorbed?

Acidic (rich in H+)

What kind of environment is required in the duodenum for optimal iron absorption?

Active process

The absorption of iron is what type of cellular process?

Na+/K+ ATPase pump

What pump is needed inside the enterocyte to maintain the balance of electrolytes during iron absorption?

Heme-bound iron and Free (nonheme) iron

What are the two forms in which ingested iron can come for absorption?

Heme carrier protein 1 (HCP1)

Through what carrier protein does heme-bound iron enter the enterocyte?

Fe2+ (ferrous) iron

What is the form of iron liberated from the vesicle inside the duodenal cell after heme-bound iron enters?

Ferritin

What is mucosal iron known as when stored inside the duodenal cell?

Ferroportin

What protein allows Fe2+ (ferrous) iron to exit the duodenal cell?

Hephaestin

What converts Fe2+ (ferrous) iron to Fe3+ (ferric) iron form upon exit from the duodenal cell?

Fe3+ (ferric) iron

What form of iron is transported through the blood by transferrin?

Duodenal cytochrome B (dcytb)

What enzyme converts ingested free (nonheme) iron from Fe3+ (ferric) iron form to Fe2+ (ferrous) iron form?

Fe2+ (ferrous) iron and acid (H+ proton)

What two components are co-transported by the divalent metal transporter 1 (DMT1) into the enterocyte?

Oral Iron Therapy

What is the preferred treatment of choice to replete iron stores?

3-6 months (or more)

How long is oral iron therapy usually given due to depleted iron stores?

3-4 weeks

After how many weeks of oral iron therapy may reticulocytosis already be evident?

65 mg

How much elemental iron is usually contained per tablet in generic brands or forms like Sangobion and Hemarate?

Once a day or alternate days

What dosing schedules for iron supplements have recent studies shown to be sufficient?

Metallic taste (lasang kalawang)

What taste do patients usually describe when taking oral iron supplements?

Ferrous fumarate

Which oral iron preparation listed contains 106 mg of elemental iron per tablet?

Black stools

What common side effect of oral iron therapy is mentioned, which is specifically noted as not melena?

Abdominal symptoms, Constipation, Nausea and vomiting

Name three common side effects of oral iron therapy.

On an empty stomach

When are oral iron supplements best absorbed?

Vitamin C

What may be given to increase the acidity needed for ferrous iron absorption?

Antacids

What common medications hinder the absorption of iron because they decrease acidity?

Intravenous means

How is Parenteral Iron Therapy administered?

Patients intolerant of oral iron, Chronic Kidney Disease (CKD) patients, Patients with malabsorption syndromes

Name three indications for parenteral iron therapy.

Iron dextran

Which form of parenteral iron is noted for being highly allergenic and can leave a prominent blackish-red ("tattoo"-like) mark if injected intramuscularly?

Iron sucrose

Which form of parenteral iron is complexed with sugar, given intravenously, and is generally less painful?

Iron carboxymaltose or Sodium ferric gluconate complex

Name one additional form of parenteral iron therapy mentioned.

Quick increase of hemoglobin

What is the advantage of parenteral iron therapy?

Anaphylaxis

What is a major, immediate disadvantage/risk associated with parenteral iron therapy?

Headache, lightheadedness, arthralgia, nausea and vomiting, flank pain

Name three side effects associated with parenteral iron therapy.

Around 10 lbs of steak a day

How much steak is needed daily, according to the source, to replenish iron?

Tannins and phytates

What substances inhibit iron absorption, found in sources like green leafy vegetables, coffee, tea, and milktea?

Thalassemia

In which patient population is iron overload usually seen due to dysregulation of iron mechanics and frequent blood transfusions?

Phlebotomy

What procedure can be performed to reduce the amount of iron in patients with iron overload who are not anemic?

250 mg

How much iron is released whenever blood is removed from the body via phlebotomy?

Chelating agents / iron chelators

What agents are given to patients with iron overload who also have anemia (like thalassemia)?

Desferrioxamine, Deferiprone, Deferasirox

Name three iron chelating agents used for iron overload.

Liver, Pancreas, Pituitary gland, Testis/Ovaries, Heart, Skin

Name three organs that may be affected by iron overload deposition.

Bronze diabetes

What is the name for the condition resulting from iron accumulation in the skin and pancreas (hemochromatosis)?

Desferrioxamine (IV)

What is the antidote for acute iron overload (e.g., iron tablet suicide attempt)?

Abdominal X-ray

What diagnostic tool is used in acute iron overload to locate the iron tablets?

Reddish (rosé wine) in color

What color does the urine appear after Desferrioxamine is given, indicating iron excretion?

Desferrioxamine (IV), Deferiprone (oral), Deferasirox (oral)

What are the three main antidotes/chelating agents for chronic iron overload and their routes of administration?

DNA synthesis and Red cell maturation

What is Folate needed for?

Vitamin B12 (Cobalamin)

What scavenges the methyl group from tetrahydrofolate (MTHF)?

Green leafy vegetables

What are the dietary sources of folate?

When boiled

Under what condition is folate concentration decreased in green leafy vegetables?

400 micrograms (μg)

What is the approximate daily requirement for folate according to Doc Tee?

Pregnant women

In which population is there a high demand for folate?

N5-Methyltetrahydrofolate (MTHF)

How does dietary folate enter the body?

Tetrahydrofolate

What remains after the methyl is taken from MTHF by Cobalamin?

Purines and thymidine

What two essential components are produced when Tetrahydrofolate enters the folate cycle?

Increased demand with poor intake, Alcoholism, Liver disease, Malabsorption, Drugs (i.e. methotrexate)

Name three causes of Folate Deficiency.

Megaloblastic anemia and Neural tube defects

What are the two major effects of Folate deficiency?

Syringomyelia and Spina bifida

What are the two specific neural tube defects mentioned that can result from Folate deficiency?

Folate reductase inhibitor (antimetabolite)

What is the Mechanism of Action (MOA) of Methotrexate?

Terminal ileum

Where is Vitamin B12 absorbed?

Intrinsic factor (IF)

What is needed for Vitamin B12 absorption?

Parietal cells in the stomach (together with hydrochloric acid)

What cells produce Intrinsic Factor?

Animal sources

What are the dietary sources of Vitamin B12?

Cyanocobalamin, Hydroxocobalamin, Methylcobalamin

Name the three different forms of Vitamin B12.

Methylcobalamin

Which form of Vitamin B12 is absorbed more easily?

Strict vegans (lack of meat sources) and Alcoholics

What two main groups of people are prone to Vitamin B12 deficiency?

Around 10 years

Approximately how long would a strict vegan need to abstain from meat before developing megaloblastic anemia?

Megaloblastic anemia and Neurological deficits

What are the two major deficiency effects of Vitamin B12?

Paresthesia

What neurological deficit involves a tingling sensation, caused by Vitamin B12 deficiency?

Ataxia

What neurological deficit, similar to cerebellar dysfunction, is associated with B12 deficiency?

MDS-like cytopenias

What condition related to the bone marrow might result from severe Vitamin B12 deficiency?

Pernicious anemia

What autoimmune condition destroys the parietal cells, leading to inability to create red cells due to lack of IF?

Gastrectomy

What surgical procedure leads to the inability to absorb Vitamin B12 due to loss of Intrinsic Factor production?

Crohn’s disease and Celiac Sprue

Name two malabsorption syndromes that can lead to megaloblastic anemia.

Epoetin

What is a recombinant, synthetic product similar to erythropoietin, made using bacteria?

Erythroid receptors on red cell progenitors

What does Epoetin interact with to produce more red cells?

Reticulocytes

What immature cells does Epoetin induce the release of from the bone marrow?

Patients with chronic kidney disease (CKD)

What patient population is prone to erythropoietin deficiency because the hormone is primarily made in the kidneys?

Subcutaneous injection

How is Epoetin typically administered?