Pharm II: Hematinic Meds

Question 1

Iron - Class, Indications, MOA

Answer 1

Class: Hematinic

Indications: Iron Deficiency

MoA: Supplement (Allows erythropoiesis to resume)

Question 2

Iron - SE/ADRs, Contraindications

Answer 2

SE/ADRs: N/V, constipation; D; Abdominal cramps; Black stools; Anaphylaxis (IV)

Contraindications: Anaphylaxis, Hemochromatosis, Hemolytic Anemia

Question 3

Iron - Dx-Dx Interactions

Answer 3

Antacids
Phenytoin
Quinolone & Tetracycline bind to Fe = less iron absorbed

Question 4

Iron - Monitor

Answer 4

Serum Ferritin, Transferrin sats [TSAT = (serum Fe/TIBC) x 100], Hgb, Reticulocytes

Question 5

Deferoxamine - Class, Indications, MOA

Answer 5

Class: Iron Chelator

Indications: Excess serum Iron Levels

MOA: Chelates iron from hemosiderin, ferritin, transferrin
(does not remove iron from Hemoglobin or Cytochromes)

Question 6

Deferoxamine - SE/ADRs, Contraindications

Answer 6

SE/ADRs: Fever, leg cramps, tachycardia, hypotension (IV); allergic reactions, ‘Pulmonary syndrome’, neurotoxicity

Contraindications: Prior anaphylaxis, renal insufficiency

Question 7

Deferoxamine - Dx-Dx, Monitor

Answer 7

Dx-Dx: none listed

Monitor: Hgb, serum iron

Question 8

Deferoxamine - Other

Answer 8

Not a primary care drug
Most often administer via IV. Seldom PO. Also administered IM, SQ
*Not for hemochromatosis treatment

Question 9

Cyanacobalamin (Vit. B12) - Class, Indications, MOA

Answer 9

Class: B-Vitamin

Indications - B12 Deficiency (presents as: Megaloblastic anemia, peripheral neuropathy, depression, CVD)

MoA: Rate limiting cofactor in conversion folate to active form, and DNA synthesis

Question 10

Cyanacobalamin (Vit. B12) - SE/ADRs, Contraindications

Answer 10

SE/ADRs: Painful by injection

Contras: none listed

Question 11

Cyanacobalamin (Vit. B12) - Dx-Dx, Monitor

Answer 11

Dx-Dx: Long term acid suppression therapy; metformin, phenytoin (long term use of these decrease B12 Levels)

Monitor: B12 & Folate levels; homocysteine, methylmalonic acid levels, Replenishment Regimens: IM 1,000mcg daily for 1-2 weeks, then 1,000mcg weekly, then 1,000mcg monthly; PO 1,000mcg daily

Question 12

Folic Acid - Physiology

Answer 12

Liver storage pool: 5-20mg, 1-6 month reserve
Tx: Folic Acid 1mg daily PO
ESRD: Dialysis removes folic acid
Chronic Alcoholism depletes FA stores in liver
R/O coexisiting B12 deficiency before treatment

Question 13

Folic Acid - Class, Indications, MOA

Answer 13

Class: Hematopoetic agents - Nutritional

Indications: Folate deficiency (megoblastic anemia, prevent of neural tube defectrs, CVD)

MoA: Cofactor in DNA synthesis

Question 14

Some Iron Physiology….

Answer 14

• Transported in blood bound to transferrin
• W/ high Fe store, iron is diverted to intestinal mucosal cells for storage
• Storage sites: intestinal mucosal cells, macrophages in liver, spleen, bone
• Iron overdose in children is LETHAL. Lock up your oral meds!

Question 15

More Iron tidbits

Answer 15

• Ferritin = iron + apoferritin
• Serum ferritin is in equilibrium w/ macrophage ferritin
• About 25% of ferrous iron dose absorbed daily:
• –Treatment goal is 200-400mg elemental iron daily (50-100mg max incorporation rate into blood daily)

Question 16

IV Iron:

Answer 16

Iron dextran (IM, IV) test dose; sodium ferric gluconate complex iron sucrose (IV)

Question 17

Little bit more about Iron..

Answer 17

• 10-30% absorbed, depending on stores; when stores increase, absorption decreases
• Food and achlorhydria decrease absorption:
• –Age decreased Fe uptake in RBC; impact of PPIs
• Ferrous iron absorbed duodenum, jejunum via DMT1

Question 18

Iron, Iron, Iron

Answer 18

• Oral: IV replenishment rates if GI absorption is normal (exception ESRD) [Ferrous sulfate preferred]
• –Administer as Ferrous Iron (FeSO4 325mg provides 65mg elemental iron)
• Reticulocytosis in 5-10days with increase in Hemoglobin in 2-4 weeks, but decreased rate absorption as stores are replenished

Question 19

My version of Iron Absorption & Transport

Answer 19

Iron moves out of the intestine and into the bloodstream –> Blood goes into Bone Marrow –> Hemoglobin synthesized; (or) goes to Hepatocytes & stored as Ferritin

Release of Iron:
- Transferrin iron complex recycled to plasma membrane and transferrin is released. Iron is then reclaimed, exported, or stored as ferritin (hepatocytes do this!)

Iron stores are turned over constantly.

Question 20

Hematopoetic Growth Factors:

Epoetin alfa & Filgrastrim

Answer 20

These guys stimulate cell lines in the bone marrow.

Epoetin alfa:

• Increases reticulocytes in 5-10 days and Hgb/Hct in 2-6 week
• Maximum Hgb on tx is 12Gm/dL
• Patients often need iron supplementation when Tx w/ ESA; need adequate iron stores
• May also need increased anti-coagulation

Question 21

Epoetin Alfa - Class, Indications, MoA

Answer 21

Class: Erythrocytosis stimulator

Indications: Low RBC secondary to ESRD, HIV, antineoplastic therapy, RA

MoA: Stimulates erythroid proliferation & differentiation; induces release of reticulocytes by marrow

Question 22

Epoetin Alfa - SE/ADRs, Contraindications

Answer 22

SE/ADRs: Secondary impact on iron deficiency, clotting; HTN, thrombosis, seizures

Contraindications: Hypersensitivity

Question 23

Epoetin Alfa - Dx-Dx, Monitor

Answer 23

Dx-Dx: Anti-coagulants, iron

Monitor: retic count, Hgb/Hct, serum ferritin

Question 24

Filgrastim - Class, Indications, MoA

Answer 24

Class; Myeloid Growth Factors

Indications: Neutropenia secondary to chemotherapy

MoA: a. Stimulates proliferation & differentiation of myeloid cells; b. increases phagocytic capacity & prolongs survival of mature neutrophils; c. mobilizes peripheral neutrophils

Question 25

Filgrastim - SE/ADRs, Contraindications, Dx-Dx, Monitor, Other

Answer 25

SE/ADRs: Fever, petechia, bone pain; Splenomegaly

Contraindications: Hypersensitivity

Dx-Dx: None listed

Monitor: CBC

Other: also GM-CSF (Granulocyte-macrophage colony-stimulating factor)