NEW YORK (Reuters Health) – Episodes of dyspnea are more common in patients treated with the antiplatelet agent than in those taking clopidogrel, although the clinical importance of this side effect seems minor in most cases.

Ticagrelor is a reversible P2Y12 adenosine diphosphate receptor antagonist. It has been submitted for FDA approval, based on results of the PLATO study in which the rate of death, stroke or MI among acute coronary syndrome patients was 16% lower with ticagrelor therapy than with clopidogrel. (See Reuters Health report on August 31, 2009)

The current findings come from a study of 123 aspirin-treated patients with coronary artery disease who were randomly assigned to ticagrelor or clopidogrel or placebo for 6 weeks. Lead investigator Dr. Robert Storey of the University of Sheffield, UK, and colleagues report their findings in the Journal of the American College of Cardiology for July 13.

Rates of dyspnea reported by patients in the three arms were 38.6% with ticagrelor, 9.3% with clopidogrel, and 8.3% among those given placebo. Three patients discontinued ticagrelor because of dyspnea, but most cases were mild and resolved within 24 hours. There were no significant changes in cardiac test results or pulmonary function tests in any of the patients, even those with dyspnea, the team found.

Dr. Storey summed up succinctly in an email message: “Mild dyspnoea is a relatively common side effect of and is generally well tolerated, whilst more troublesome dyspnoea is uncommon.”

Furthermore, he added, “We have not seen any additional problems in patients with lung disease to date. Consequently ticagrelor seems appropriate therapy for reducing risk of mortality in a broad range of patients with acute coronary syndromes.”

The study was funded by AstraZeneca, the maker of ticagrelor (proposed brand name, Brilinta).

Reference:

J Am Coll Cardiol 2010; 56:185–193.