Why does ticagrelor induce dyspnea?
ABSTRACT In studies that compared the reversible P2Y12 inhibitor ticagrelor with the irreversible inhibitor clopidogrel, dyspnea was observed more frequently among ticagrelor-treated patients than among clopidogrel-treated patients. Because dyspnea was not associated with acidosis, pulmonary or cardiac dysfunction, alterations in the mechanisms and pathways of the sensation of dyspnea may be involved in its pathogenesis. It has been hypothesised that the sensation of dyspnea in ticagrelor-treated patients is triggered by adenosine, because ticagrelor inhibits its clearance, thereby increasing its concentration in the circulation. However, dipyridamole, a much stronger inhibitor of adenosine clearance than ticagrelor, usually does not cause dyspnea. We hypothesise that inhibition of P2Y12 on sensory neurons increases the sensation of dyspnea, particularly when reversible inhibitors are used. We base our hypothesis on the following considerations: 1) cangrelor and elinogrel, which, like ticagrelor, are reversible P2Y12 inhibitors, also increase the incidence of dyspnea; 2) it is biologically plausible that inhibition of P2Y12 on sensory neurons increases the sensation of dyspnea; 3) inhibition of P2Y12 on platelets (which do not have a nucleus) by clopidogrel is permanent, despite the once daily administration and the short plasma half-life of the inhibitor; 4) in contrast, inhibition of P2Y12 on neurons by clopidogrel may be temporary and transient, because neurons have a nucleus and can therefore rapidly replace the inhibited receptors with newly synthetised ones; 5) inhibition of P2Y12 on neurons by reversible inhibitors is permanent, because the plasma drug concentration is maintained high by repeated dosing, in order to ensure permanent inhibition of platelet P2Y12.
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ABSTRACT: Dual antiplatelet therapy consisting of one of the P2Y12 receptor inhibitors in conjunction with aspirin is the mainstay of treatment for patients with acute coronary syndromes (ACS) and those undergoing percutaneous coronary interventions (PCI). In recent years, multiple extra-platelet features of P2Y12 receptor antagonists have been reported in numerous clinical trials. The aim of this review is to summarise reported pleiotropic effects of clopidogrel, prasugrel, ticagrelor and other P2Y12 receptor blockers. We included observations made both in human and in animal models, together with proposed mechanisms of action for described features. If confirmed in randomised studies and properly applied to everyday practice, the observed extra-platelet actions could enable us to improve efficacy of ACS and post-PCI treatment, as well as to confine mortality and occurrence rate of cardiovascular events.Thrombosis and Haemostasis 04/2014; 112(2). · 6.09 Impact Factor
- International journal of cardiology 02/2014; · 6.18 Impact Factor
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ABSTRACT: Dyspnea has been consecutively reported in some trials evaluating new P2Y12 inhibitors. We aimed to review and quantify the global risk of dyspnea of recent P2Y12 inhibitor drugs, and evaluate its association with the reversibility profile of P2Y12 inhibitors. A database search (March 2013) retrieved randomized controlled trials (RCTs) comparing new antiplatelet drugs (ticagrelor, prasugrel, cangrelor, elinogrel) with clopidogrel. The primary outcome was the incidence of dyspnea. Placebo-controlled trials were excluded. Meta-analysis was performed and estimates were expressed as risk ratio (RR) and 95 % confidence intervals (95 % CIs). Dyspnea incidence was evaluated according to the reversibility profile of P2Y12 antagonists. We found eight RCTs including 41,289 patients. Prasugrel was not associated with an increased risk of dyspnea (RR 1.09, 95 % CI 0.93-1.27), whereas ticagrelor (RR 1.95, 95 % CI 1.37-2.77), cangrelor (RR 2.42, 95 % CI 1.36-4.33), and elinogrel (RR 3.25, 95 % CI 1.57-6.72) showed an increased risk of dyspnea. Reversible inhibitors significantly increased the risk of dyspnea compared with the irreversible inhibitor, prasugrel, through adjusted indirect comparison (RR 1.99, 95 % CI 1.40-2.82). The reversible P2Y12 antagonists ticagrelor, cangrelor, and elinogrel have an increased incidence of dyspnea in increasing order when compared with irreversible P2Y12 inhibitors such as clopidogrel or prasugrel.American Journal of Cardiovascular Drugs 03/2014; · 2.20 Impact Factor