antiplatelet and anticoagulant therapies

side effects of aspirin

GI bleeding, hypersensivity and bronchospasms

side effects of P2Y12 antagonists

dyspepsia, diarrhoea and rashes

dipyridamole side effect

GI disturbances, headaches, dizziness angina pectoris, rashes and myalglia (no bleeding)

purpura

purple bruises caused by bleeding underneath the skin

thrombocytopenic

number of platelets in the blood is lower than normal

thrombotic

formation of a blood clot inside a blood vessel

2 types of thrombotic thrombocytopenic purpura

inherited and aquired

what is inherited TTP

Mutations in the ADAMTS13 gene or immunodeficiency in the ADAMTS13 enzyme that breaks down the VWF

(rare, affecting mainly children and infants).

What is acquired TTP (more common)

•Drug-induced (antiplatelet thienopyridines TICLOPIDINE, CLOPIDOGREL, PRASUGREL; chemotherapy; quinine)

•Diseases and conditions (pregnancy; viral, infections, HIV; hepatitis, combined contraceptives)

Dipyridamole MOA

Inhibits PDE so ↑ cAMP/ cGMP

inhibits platelet activation

prolongs cAMP and cGMP mediated vasodilation in sm muscle cells

Blocks adenosine uptake into platelets and EC so raising extracellular adenosine concentration

-Adenosine induces vasodilation

(via A2_AR increasing cAMP and cGMP)

6,7,8 drug list adverse effects

thrombocytopenia

6,7,8 MOA

Resting GIIb/IIIa R on platelets are ‘ligand-unreceptive’

Activated to ‘ligand-receptive’ conformation by platelet agonists

(ADP/ thrombin/ TxA2 / collagen)

Fibrinogen creates cross-linked bridges between GIIb/IIIa Rs to induce

platelet aggregation

Hence blocking the receptors prevents aggregation