Pharm II: Hematinic Meds Flashcards
Iron - Class, Indications, MOA
Class: Hematinic
Indications: Iron Deficiency
MoA: Supplement (Allows erythropoiesis to resume)
Iron - SE/ADRs, Contraindications
SE/ADRs: N/V, constipation; D; Abdominal cramps; Black stools; Anaphylaxis (IV)
Contraindications: Anaphylaxis, Hemochromatosis, Hemolytic Anemia
Iron - Dx-Dx Interactions
Antacids
Phenytoin
Quinolone & Tetracycline bind to Fe = less iron absorbed
Iron - Monitor
Serum Ferritin, Transferrin sats [TSAT = (serum Fe/TIBC) x 100], Hgb, Reticulocytes
Deferoxamine - Class, Indications, MOA
Class: Iron Chelator
Indications: Excess serum Iron Levels
MOA: Chelates iron from hemosiderin, ferritin, transferrin
(does not remove iron from Hemoglobin or Cytochromes)
Deferoxamine - SE/ADRs, Contraindications
SE/ADRs: Fever, leg cramps, tachycardia, hypotension (IV); allergic reactions, ‘Pulmonary syndrome’, neurotoxicity
Contraindications: Prior anaphylaxis, renal insufficiency
Deferoxamine - Dx-Dx, Monitor
Dx-Dx: none listed
Monitor: Hgb, serum iron
Deferoxamine - Other
Not a primary care drug
Most often administer via IV. Seldom PO. Also administered IM, SQ
*Not for hemochromatosis treatment
Cyanacobalamin (Vit. B12) - Class, Indications, MOA
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
Cyanacobalamin (Vit. B12) - SE/ADRs, Contraindications
SE/ADRs: Painful by injection
Contras: none listed
Cyanacobalamin (Vit. B12) - Dx-Dx, Monitor
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
Folic Acid - Physiology
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
Folic Acid - Class, Indications, MOA
Class: Hematopoetic agents - Nutritional
Indications: Folate deficiency (megoblastic anemia, prevent of neural tube defectrs, CVD)
MoA: Cofactor in DNA synthesis
Some Iron Physiology….
- 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!
More Iron tidbits
- 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)
IV Iron:
Iron dextran (IM, IV) test dose; sodium ferric gluconate complex iron sucrose (IV)
Little bit more about Iron..
- 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
Iron, Iron, Iron
- 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
My version of Iron Absorption & Transport
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.
Hematopoetic Growth Factors:
Epoetin alfa & Filgrastrim
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
Epoetin Alfa - Class, Indications, MoA
Class: Erythrocytosis stimulator
Indications: Low RBC secondary to ESRD, HIV, antineoplastic therapy, RA
MoA: Stimulates erythroid proliferation & differentiation; induces release of reticulocytes by marrow
Epoetin Alfa - SE/ADRs, Contraindications
SE/ADRs: Secondary impact on iron deficiency, clotting; HTN, thrombosis, seizures
Contraindications: Hypersensitivity
Epoetin Alfa - Dx-Dx, Monitor
Dx-Dx: Anti-coagulants, iron
Monitor: retic count, Hgb/Hct, serum ferritin
Filgrastim - Class, Indications, MoA
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
Filgrastim - SE/ADRs, Contraindications, Dx-Dx, Monitor, Other
SE/ADRs: Fever, petechia, bone pain; Splenomegaly
Contraindications: Hypersensitivity
Dx-Dx: None listed
Monitor: CBC
Other: also GM-CSF (Granulocyte-macrophage colony-stimulating factor)
