Pharmacology

Question 1

Mechanism of action of Aprepitant

Answer 1

Blocks neurokinin-1 receptors in the brain, preventing substance P release.
Antiemetic for chemotherapy-induced N/V

Question 2

Mechanism of action of Hydroxyurea

Answer 2

Inhibits ribonucleotide reductase → ↓DNA synthesis (S-phase specific).
Also ↑ HbF

Question 3

Mechanism of action of Argstroban, Dabigatran and Lepirudin

Answer 3

Direct thrombin inhibitors.
Inhibit activity of free and clot-associated thrombin.
Do not require antithrombin III

Question 4

Development of IgG vs heparin-bound platelet factor 4. The complex activates platelets → thrombosis and thrombocytopenia

Answer 4

Heparin-induced thrombocytopenia (HIT) type 2

Question 5

Mechanism of action of Vincristine

Answer 5

Vinca alkaloid that binds β-tubulin and inhibits its polymerization into microtubules.
M-phase arrest

Question 6

Mechanism of action of Warfarin

Answer 6

Inhibits epoxide reductase.

Interferes with γ carboxylation of vit K dependent clotting factors

Question 7

Mechanism of action of Bleomycin and mention the most important adverse effect

Answer 7

Antitumor antibiotic that induces free radical formation, so breaks in DNA strands.
Causes pulmonary fibrosis

Question 8

Mechanism of action of Abciximab

Answer 8

Binds to glycoprotein receptor IIb/IIIa (fibrinogen receptor) on activated platelets, preventing aggregation

Question 9

Mechanism of action of Bortezomib

Answer 9

Proteasome inhibitor, induce arrest at G2-M phase and apoptosis. There’s accumulation of misfolded proteins → cytotoxic effects

Question 10

Monoclonal antibody against HER-2 (c-erbB2), a tyrosine kinase receptor
Herceptin.

Answer 10

Trastuzumab

Question 11

Mechanism of action of Unfractionated Heparin

Answer 11

Activates antithrombin, ↓ action of IIa (thrombin) and factor Xa. Binds both antithrombin and thrombin

Question 12

Association between CLL and BCL-2

Answer 12

BCL-2 is an antiapoptotic protein. CLL overexpresses BCL-2 → ↓ caspase activation → tumorigenesis

Question 13

How do you monitor warfarin effect?

Answer 13

With INR and PT

Question 14

Why is desmopressin used as treatment of von Willebrand disease?

Answer 14

Because it ↑ vWF release from endothelial cells and ↑ factor VIII levels (tx in hemophilia A)

Question 15

Mechanism of action of Bevacizumab

Answer 15

Monoclonal antibody against VEGF. Inhibits angiogenesis

Question 16

Why is the warfarin therapeutic effect delayed 3-5 days?

Answer 16

Because it blocks generation of new clotting factors, until preexisting ones are consumed. This is why there’s risk of initial hypercoagulation

Question 17

Pancytopenia characterized by anemia, leukopenia and thrombocytopenia with normal cell morphology and hypocellular bone marrow, caused by radiation, viral agents, CBZ, etc

Answer 17

Aplastic anemia

Question 18

How to treat Heparin and warfarin overdose, respectively

Answer 18

Heparin rapid antidote: protamine sulfate

Warfarin rapid reversal: fresh frozen plasma or PCC

Question 19

Mechanism of action of Etoposide

Answer 19

Inhibits topoisomerase II → ↑ DNA degradation (cell cycle arrest in G2 and S phases)