Agents Used in Cytopenias and Hematopoietic Growth Factors

Flashcards covering pharmacological agents for cytopenias, including iron therapy, Vitamin B12 and folate metabolism, erythropoietin, myeloid growth factors, and platelet growth factors.

Microcytic Hypochromic Anemia

Anemia characterized by small, pale red blood cells, most commonly caused by Iron Deficiency.

Megaloblastic Anemia

A maturation defect due to Vitamin $B_{12}$ or Folate deficiency where cell division stops but cytoplasm continues to grow.

Pernicious Anemia

A condition of $B_{12}$ malabsorption caused by a deficiency in intrinsic factor (IF), often due to antibodies against parietal cells.

Transferrin

The protein responsible for transporting iron throughout the body.

Ferritin

The protein used for the storage of iron in the body; levels should be monitored to ensure stores are full to prevent anemia recurrence.

Hespisidin

The main regulatory protein that controls the absorption of iron and its release from macrophages.

Oral Iron Treatment Preparations

Preferred ferrous salts including Ferrous sulfate, ferrous gluconate, and ferrous fumarate.

Parenteral Iron Treatment Drugs

Injectable iron formulations used for patients who cannot tolerate oral therapy, including Iron dextran, iron sucrose, and ferric carboxymaltose.

Deferoxamine

An intravenous (IV) or subcutaneous (SC) chelator that is the gold standard for treating acute iron poisoning.

Deferasirox

An oral chelator used for chronic iron accumulation (hemochromatosis) with higher patient compliance than injectable agents.

Deferipron

An oral iron chelator used in the management of iron loading.

Therapeutic Phlebotomy

Also known as bloodletting or venesection, a simple procedure used to treat polycythemia vera, hereditary hemochromatosis, and porphyria cutanea tarda.

Vitamin $B_{12}$ Storage

Stored in the liver, which contains enough (typically $3-5\text{ mg}$) to last for several years.

Methylmalonic Acid (MMA)

A metabolic marker that rises in the serum specifically during Vitamin $B_{12}$ deficiency.

Folate Trap

A condition in $B_{12}$ deficiency where folate is trapped in the methyl form, making it unusable for DNA synthesis.

Cyanocobalamin / Hydroxocobalamin

Forms of Vitamin $B_{12}$ usually administered via Intramuscular (IM) injection for patients with malabsorption.

Neural Tube Defects

Developmental issues such as spina bifida that can be significantly reduced by folate supplementation before and during early pregnancy.

Erythropoietin (EPO)

A hormone secreted from the kidneys in response to hypoxia that stimulates the proliferation of erythroid precursor cells.

Darbepoetin Alfa

A longer-acting erythropoietin preparation that allows for weekly dosing.

Mircera (CERA)

Methoxy polyethylene glycol-epoetin beta, a continuous erythropoietin receptor activator that offers once-a-month dosing.

EPO Safety Target

The risk of stroke and cardiovascular events increases when hemoglobin exceeds a target of $11-12\text{ g/dL}$; aggressive increases should be avoided.

Roxadustat

An HIF-Prolyl Hydroxylase Inhibitor that mimics the hypoxia response to enhance endogenous EPO production and iron absorption orally.

Luspatercept

An erythroid maturation agent that binds TGF-beta superfamily ligands to induce erythrocyte maturation in Beta-Thalassemia and MDS.

Filgrastim (G-CSF)

A myeloid growth factor that specifically increases neutrophil production.

Sargramostim (GM-CSF)

A broad-spectrum myeloid growth factor that increases neutrophils, macrophages, and eosinophils.

Oprelvekin (Interleukin-11)

A megakaryocytic factor used to prevent thrombocytopenia, though it may cause edema and heart arrhythmias.

Romiplostim

A peptide-structure Thrombopoietin (TPO) receptor agonist administered subcutaneously.

Eltrombopag

A non-peptide oral TPO receptor agonist used for chronic ITP; requires monitoring for liver toxicity.

Iron Deficiency Lab Profile

Characterized by \text{Serum iron } \boldsymbol{\tiny \textdownarrow}, \text{TIBC } \boldsymbol{\tiny \textuparrow}, and \text{Ferritin } \boldsymbol{\tiny \textdownarrow}.

Plerixafor

A CXCR4 receptor antagonist used with G-CSF to mobilize hematopoietic stem cells from the bone marrow to the blood for transplantation.

SDF-1alpha (CXCL12)

A chemokine secreted by the bone marrow stroma that binds to CXCR4 to anchor stem cells in the marrow niche.