platelets

A Randomized Double-Blind Trial Of 3 Aspirin Regimens To Optimize Antiplatelet Therapy In Essential Thrombocythemia

A Randomized Double-Blind Trial Of 3 Aspirin Regimens To Optimize Antiplatelet Therapy In Essential Thrombocythemia

In the July 9, 2020 publication of the journal Blood, investigators reported on randomized double blind trial of 3 different aspirin regimens in essential thrombocythemia.  This study was a multicenter double-blind trial, investigating the efficacy of 3 different aspirin regimens for optimizing platelet Cox 1 inhibition while preserving Cox 2 dependent vascular thromboresistance.  

245 patients who were on chronic once daily low-dose aspirin, were randomized in a 1:1:1 fashion to receive 100 mg of aspirin 1, 2 or 3 times daily for 2 weeks.  Serum thromboxane B2, and urinary prostacyclin metabolite were measured at randomization and after 2 weeks. These served as primary surrogate endpoints of efficacy and safety, respectively.  Urine thromboxane metabolite excretion, gastrointestinal tolerance, and ET related symptoms were also investigated. 

Evaluable patients assigned to the twice daily and thrice daily regimens showed substantially reduced into individual variability in the lower median value of serum thromboxane B2 compared with the once daily arm: 4 (2.1–6.7, n=79), 2.5 (1.4–5.65, n=79,) and 19.3 (9.7–40, n=85), respectively.  Urinary PGIM was comparable in the 3 arms.  Urinary TXM was reduced by 35% in both experimental arms.  Patients in the thrice daily arm reported a higher abdominal discomfort score per investigators.  

The authors concluded “the currently recommended aspirin regimen of 75-100 mg once daily for cardiovascular prophylaxis appears to be largely inadequate in reducing platelet activation in the vast majority of patients with essential thrombocytosis.  Antiplatelet response to low-dose aspirin can be markedly improved by shortening the dose interval to 12 hours with no improvement with further reductions”

https://ashpublications.org/Blood/article-abstract/136/2/171/454293/A-randomized-double-blind-trial-of-3-aspirin?redirectedFrom=fulltext

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