Drugs and Diseases: hematopoiesis Flashcards
describe microcytic, hypochromic anemias?
- impaired Hb synthesis
- Fe deficiency
- lead poisoning
- thalassemia
describe macrocytic, normochromic anemias?
- impaired DNA synthesis
- B12 or B9 (folate) deficiency
describe normocytic, normochromic anemias?
- red cell loss
- severe bleeding
- sickle cell anemia
- pyruvate kinase deficiency
- G6PDH deficiency
what is thrombycytopenia?
low platelet count
name 2 congenital bleeding disorders
- Bernard-Soulier syndrome
2. fibrinogen deficiency
what is bernard-soulier syndrome?
GPIb-IX deficiency
name an acquired bleeding disorder
thrombocytopenia:
- defective formation of megakaryocytes (leukemia)
- excessive destruction of platelets (anti-platelet Abs)
what are 3 antiplatelet drugs and how do these function?
plavix: inhibit receptor for ADP
ticlopidine: inhibit receptor for ADP
dipyridamole: bind ADP, prevent binding to receptor
used to treat/prevent arteriral thrombosis
what do leeches have that inhibits clot formation?
hirudin
what is dicoumarol?
vitamin K antagonist -> prevents binding to Ca2+ (spoiled clover)
what is warfarin?
vitamin K antagonist -> anticoagulant
aPTT: what does it test, what does long time mean, what is it used to monitor?
activated partial thromboplastin time
- test of INTRINSIC pathway
- long time: deficiency in VIII, IX, XI, XII
- monitor intravenous heparin
PT: what does it test, what does long time mean, what is it used to monitor?
prothrombin time
- test of EXTRINSIC pathway
- factor III added to plasma -> specific for reduced VII, but also X, II
- monitor warfarin
what is bleeding time used to measure?
platelet fxn
what is PT used to measure?
- vitamin K deficiency
- warfarin/oral anticoagulant
- liver disease (good marker for liver failure after acetaminophen overdose)
what is aPTT used to measure?
- heparin therapy
- hemophilia A
what does congenital deficiency in antithrombin III cause?
-increased risk of venous thromboembolism (DVT, PE)
what does factor V leiden mean?
variant factor V - resistant to protein C -> increase in clotting
what is hemophilia A/classic hemophilia?
- deficiency in VIIIa (which activates Xa)
- x-linked, many mutations
- prolonged wound bleeding + easy bruising
treatment for hemophilia?
- human plasma
- recombinant factor VIII
what is von Willebrand disease?
- defective platelet adhesion -> increased bleeding time
- more common than hemophilia
what two deficiencies can cause hemolytic anemia?
- pyruvate kinase deficiency
- G6PDH deficiency
how does pyruvate kinase deficiency cause hemolytic anemia?
less ATP -> failed cation gradient -> lose K+, H2O -> cell dehydration -> hemolytic anemia
why are symptoms of pyruvate kinase hemolytic anemia less severe than expected?
2,3-BPG results in greater release of O2 to tissues
treatment for pyruvate kinase deficiency?
- transfusions
- splenectomy (to prevent hemolytic anemia)
