T13 - Hematopoeisis Drug

What is the mean corpuscular volume (MCV) cutoff for defining microcytic anemia?

< 80 fL

What distinct nail abnormality is a classic clinical sign of severe iron deficiency anemia?

Koilonychia (spoon nails)

Which iron chelator is administered via injection to treat acute iron intoxication and thalassemia iron overload?

Deferoxamine

Which oxidation state of iron is best absorbed by the gastrointestinal tract?

Ferrous iron (Fe2+)

Which vitamin significantly enhances the gastrointestinal absorption of oral iron?

Vitamin C (ascorbic acid)

Which two antibiotic classes form unabsorbable complexes with oral iron supplements?

Fluoroquinolones and tetracyclines

What harmless gastrointestinal side effect of oral iron therapy can mimic gastrointestinal bleeding?

Dark stools

What route of administration is used for the iron chelators deferiprone and deferasirox?

Oral

Which severe hematologic adverse effect requires weekly CBC monitoring in patients taking deferiprone?

Agranulocytosis

What is the mean corpuscular volume (MCV) cutoff for defining macrocytic anemia?

100 fL

Which nutritional deficiency causes a macrocytic anemia accompanied by neurological symptoms?

Vitamin B12 deficiency

Which injectable Vitamin B12 formulation is preferred due to its longer circulating half-life?

Hydroxocobalamin

Which folate analog is administered via injection to treat methotrexate toxicity?

Leucovorin (folinic acid)

Which medication is specifically indicated for the targeted treatment of sickle cell anemia?

Voxelotor

Which medication is used to treat normocytic anemia caused by chronic renal failure?

Erythropoietin (Epoetin alfa)

Which anti-HIV medication classically causes myelosuppression leading to normocytic anemia?

Zidovudine

Which cardiovascular adverse effect occurs in 20-30% of patients receiving erythropoietin therapy?

Hypertension

What severe circulatory complication is a risk of rapid hematocrit rise during erythropoietin therapy?

Thrombotic complications (stroke, thromboembolism)

What is the mechanism of action of Filgrastim?

Granulocyte colony-stimulating factor (G-CSF) analog

Which hematopoietic growth factor increases circulating levels of neutrophils, erythrocytes, and platelets?

GM-CSF (Sargramostim)

What common musculoskeletal adverse effect is associated with G-CSF and GM-CSF therapy?

Bone and joint pain (arthralgia)

Which class of anticlotting drugs is generally preferred for the prevention and treatment of arterial thrombosis?

Antiplatelets

Which class of anticlotting drugs is generally preferred for the prevention and treatment of venous thrombosis?

Anticoagulants

What is the specific mechanism of action of aspirin?

Irreversible COX-1 inhibitor

How many days does the antiplatelet effect of aspirin typically last?

7-10 days

Which potent stimulator of platelet aggregation is suppressed by aspirin therapy?

Thromboxane A2 (TXA2)

Which respiratory adverse effect can be triggered by aspirin due to shunting of arachidonic acid?

Bronchoconstriction

What is the mechanism of action of clopidogrel and ticlopidine?

ADP (P2Y12) receptor antagonists

Is clopidogrel administered as an active drug or a prodrug?

Prodrug

Which ADP receptor antagonist is an active drug that does NOT require hepatic activation?

Ticagrelor

Which specific hepatic cytochrome P450 enzyme is primarily responsible for activating clopidogrel?

CYP2C19

Which proton pump inhibitor significantly decreases clopidogrel efficacy by inhibiting CYP2C19?

Omeprazole

What rare but severe microangiopathic complication is associated with ticlopidine?

Thrombotic thrombocytopenic purpura (TTP)

What is the mechanism of action of abciximab?

Glycoprotein IIb/IIIa inhibitor

Which two endogenous proteins normally bind to the Glycoprotein IIb/IIIa receptor to mediate platelet aggregation?

Fibrinogen and vitronectin

Which two coagulation factors are equivalently inactivated by unfractionated heparin (UFH)?

Factor Xa and Thrombin (Factor IIa)

What is the endogenous target that heparin molecules bind to exert their anticoagulant effect?

Antithrombin (Antithrombin III)

Which coagulation factor is preferentially inactivated by low molecular weight heparin (LMWH)?

Factor Xa

Which synthetic anticoagulant contains ONLY the active pentasaccharide sequence and exclusively inhibits Factor Xa?

Fondaparinux

Which route of elimination is utilized by unfractionated heparin?

Reticuloendothelial system (macrophages)

What route of elimination is utilized by LMWH (enoxaparin) and fondaparinux?

Renal excretion (glomerular filtration)

Which anticoagulant is a preferred alternative for patients who develop Heparin-Induced Thrombocytopenia (HIT)?

Fondaparinux

Which skeletal complication is associated with the extended use (3-6 months) of unfractionated heparin?

Osteoporosis

Which electrolyte abnormality can be caused by unfractionated heparin due to suppression of aldosterone synthesis?

Hyperkalemia

What specific reversal agent is used to treat severe bleeding caused by unfractionated heparin overdose?

Protamine sulfate

What is the efficacy of protamine sulfate in reversing the anticoagulant effects of fondaparinux?

Ineffective (Cannot use)

Which laboratory test is routinely used to monitor the efficacy of unfractionated heparin?

Activated partial thromboplastin time (aPTT)

What is the mechanism of action of warfarin?

Vitamin K epoxide reductase (VKOR) inhibitor

Which specific clotting factors require vitamin K-dependent gamma-carboxylation for activity?

Factors II, VII, IX, X, Protein C, Protein S

What is the approximate duration of time required for warfarin to reach its full antithrombotic effect?

4-5 days

Is warfarin safe to administer during pregnancy?

No (Pregnancy Category X)

What fetal complications are classically associated with warfarin use during pregnancy?

Hemorrhage and bone defects

Which antifungal medication increases warfarin toxicity by inhibiting CYP2C9 and CYP3A4?

Fluconazole

Which laboratory parameter is routinely used to monitor the efficacy of warfarin?

Prothrombin time (PT) / INR

Which specific clotting factor has the shortest half-life and primarily determines the initial PT prolongation during warfarin therapy?

Factor VII (3-6 hours)

Which blood product provides the most rapid reversal of severe warfarin-induced bleeding?

Prothrombin complex concentrate (PCC) or Fresh Frozen Plasma

What is the reversal agent for warfarin toxicity that takes 6-24 hours to become effective?

Vitamin K

What is the specific mechanism of action of dabigatran?

Direct thrombin inhibitor

What is the mechanism of action of rivaroxaban and edoxaban?

Direct Factor Xa inhibitors

Which class of drugs accelerates the conversion of plasminogen to plasmin?

Fibrinolytics (Thrombolytics)

Which fibrinolytic agent has low specificity and affects both fibrin-bound and free plasminogen?

Streptokinase

Which fibrinolytic agent has high specificity and exclusively targets fibrin-bound plasminogen?

Tissue plasminogen activator (t-PA / Alteplase)

Which fibrinolytic agent carries a specific risk of allergic reactions due to its bacterial origin?

Streptokinase

Which medication is used to increase levels of von Willebrand factor and Factor VIII in mild bleeding disorders?

Desmopressin

What is the mechanism of action of tranexamic acid?

Lysine analog that inhibits plasminogen activation

What is the specific cellular target of vorapaxar?

PAR-1 receptor antagonist

What is the mechanism of action of dipyridamole and cilostazol?

Phosphodiesterase (PDE) inhibitors

Which specific CYP2C19 genotype is associated with poor activation of clopidogrel?

CYP2C19 2/2 (Poor metabolizers)

What route of administration is used for the direct Factor Xa inhibitors rivaroxaban and edoxaban?

Oral

What is the role of interleukin-11 (oprelvekin) in hematopoietic therapy?

Stimulates platelet production