Heart attack drug proven to have no rebound effect

(Medical Xpress)—Clopidogrel, a drug prescribed to thousands of people who have had a heart attack, can be safely withdrawn with no 'rebound effect', according to a study by Aberdeen scientists.

The drug works by lowering the stickiness of platelets and preventing clots forming. Heart attacks occur when platelets in the blood form clots in the coronary artery.

Current guidelines recommend that patients are prescribed clopidogrel for up to 12 months following a heart attack.

However, recent reports had shown that a higher than expected number of patients experienced blood clots within a short time of stopping this drug.

Concerns were raised that the drug may be causing platelets within the blood to become more active.

But a three year study of patients who had a heart attack or blocked leg artery, performed by experts from the University of Aberdeen's Institute of Medical Sciences, has found no evidence for increased blood platelet activity after planned discontinuation of the drug.

The findings of the research, which was funded by Heart Research UK, are published in the Journal of the American College of Cardiology (JACC).

Dr Isobel Ford from the University of Aberdeen's Institute of Medical Sciences said: "Our trial recruited 171 patients who had narrowed arteries in their heart or leg arteries. They were given clopidogrel and aspirin, or a placebo capsule and aspirin, to take for one month. We measured blood platelet activity using a range of tests before, during treatment, and after stopping the medicine.

"Our study is the first to show that platelet activity after stopping clopidogrel is not any higher than it would have been without the drug."

Julie Brittenden, Professor in Vascular Surgery & Deputy Head of Division of Applied Medicine at the University of Aberdeen said: "Our findings provide reassurance for doctors that they can safely halt therapy using clopidogrel in patients that are stable, as per current guidelines, without leading to a rebound in platelet activity."