(See also Overview of Platelet Disorders.)
Acquired abnormalities of platelet function are very common. Causes include
Drugs
Systemic disorders
Cardiopulmonary bypass
Acquired platelet dysfunction is suspected and diagnosed when unusual or prolonged bleeding is observed and other possible diagnoses (eg, thrombocytopenia, coagulation abnormalities) have been eliminated. Platelet aggregation studies are unnecessary.
Drugs
adenosine
Aspirin and NSAIDs prevent cyclooxygenase-mediated production of thromboxane A2. This effect can last 5 to 7 days. Aspirin modestly increases bleeding in healthy people but may markedly increase bleeding in older patients and those with underlying platelet dysfunction or a severe coagulation disturbance (eg, patients receiving heparin, patients with severe hemophilia). Clopidogrel, prasugrel, and ticagrelor all can markedly reduce platelet function and increase bleeding.
A number of other drugs can also cause platelet dysfunction (1).
Systemic disorders
Many disorders (eg, myeloproliferative neoplasms, myelodysplastic disorders, uremia, macroglobulinemia, multiple myeloma, cirrhosis, systemic lupus erythematosus) can impair platelet function.
> 100 g/L) by transfusion or by giving erythropoietin also reduces bleeding.
Cardiopulmonary bypass
General reference
1. Scharf RE: Drugs that affect platelet function. Semin Thromb Hemost 38(8): 865–883, 2012. doi: 10.1055/s-0032-1328881