Blood Thinners and Hemostasis Overview

A protein produced by the body that prevents the ADAMTS13 enzyme from functioning properly.

A genetic disorder characterized by a deficiency or dysfunction of von Willebrand factor (VWF), a protein essential for blood clotting.

VWF deficiency or dysfunction affects primary hemostasis by impairing platelet adhesion and aggregation.

VWF acts as a chaperone protein for factor VIII (FVIII), protecting it from degradation and clearance in the bloodstream.

The initial response to blood vessel injury, where the injured vessel constricts to reduce blood flow.

The second step in hemostasis, involving platelets adhering to the injured area and forming a temporary plug.

A substance exposed in the vascular wall when injured which attracts platelets for plug formation.

COX-1 and COX-2 inhibitors can cause sodium retention and a decrease in glomerular filtration rate.

Fetal COX-2 inhibition can lead to neonatal chronic renal failure. Therefore, maternal use should be avoided until further studies confirm safety.

COX inhibitors can increase the risk of bleeding due to inhibition of thromboxane A2 (TXA2) production.

Discontinue COX inhibitors 7 days prior to elective surgery due to the risk of excessive bleeding.

COX inhibitors should be avoided during cataract surgery because they can cause corneal bleeding.

Chronic use of COX inhibitors can lead to progressive renal dysfunction due to vasoconstriction of renal arteries.

COX inhibitors can exacerbate asthma by shifting arachidonic acid metabolism towards the lipoxygenase pathway.

COX inhibitors can cause tinnitus, headache, dizziness, confusion, hearing loss, and metabolic acidosis due to salicylate toxicity.

Reye syndrome is a hypersensitivity reaction that causes swelling in the liver and brain. It can occur at any age but usually affects children and teenagers after a viral infection.

Cilostazol helps improve blood flow to the legs by relaxing blood vessels, reducing pain caused by insufficient blood supply during walking. It's usually taken twice a day, but the dosage can be lowered if used with certain medications that increase its effects.

Cilostazol can interact with medications impacting the liver's metabolism, like erythromycin and ketoconazole, potentially affecting its effectiveness or causing side effects.

Cilostazol shouldn't be used by individuals with heart failure because it dilates blood vessels excessively, which can worsen the condition.

Clopidogrel, a common antiplatelet medication, prevents platelets from clumping together by blocking a specific receptor on their surface. This action helps prevent blood clots forming in patients with heart disease.

Clopidogrel irreversibly blocks the receptor on platelets, meaning they're 'turned off' for a prolonged time. This makes it crucial to use caution when administering clopidogrel, as it can significantly increase bleeding risk.

A medication used in stress testing to dilate blood vessels and mimic the effects of exercise.

A condition where blood flow to the legs is reduced, causing pain and cramping during exercise.

A medication that is the first-line treatment for PAD.

A type of drug that inhibits the enzyme phosphodiesterase, leading to an increase in cAMP.

A messenger molecule that plays a crucial role in many cellular processes, including vasodilation and platelet aggregation.

The process of blood vessels widening.

The process of platelets clumping together to form a clot.

A medication that reduces the risk of stroke in patients with history of thrombotic stroke or transient ischemic attacks.

A symptom of PAD characterized by pain and cramping in the legs during exercise.

A medication commonly used to treat bacterial infections.

A medication that inhibits phosphodiesterase (PDE), leading to increased cyclic adenosine monophosphate (cAMP) levels.

Dipyridamole is a PDE inhibitor commonly used for patients with peripheral artery disease, particularly those with diabetes.

Dipyridamole inhibits the breakdown of cAMP, leading to increased levels. This inhibits platelet aggregation and promotes vasodilation.

Dipyridamole blocks the adenosine transporters on platelets, which raises adenosine levels in the bloodstream. This further inhibits platelet aggregation and improves blood flow.

Dipyridamole is often used as an adjunct therapy with anticoagulants in patients with prosthetic heart valves who cannot tolerate aspirin.

Dipyridamole can be used for cardiac stress testing to indirectly evaluate heart function.

Common side effects of Dipyridamole include exacerbation of angina after IV administration, hypotension from vasodilation, gastrointestinal upset, and dizziness.

Combining Dipyridamole with other medications that increase the risk of bleeding, such as Warfarin, can lead to a higher risk of hemorrhage.

PDE inhibitors are more commonly used in patients with peripheral artery disease because this population often has co-existing conditions such as diabetes.

PDE inhibitors are not preferred as first-line treatment for pregnant women in the third trimester due to concerns about prolonged labor and increased risk of hemorrhage.