Merck & Co has said that it halted one study on anticlotting pill vorapaxar and puts restrictions on another was due to an increase in brain in bleeds among patients with a history of strokes.
Researchers announced they would put an end to the vorpaxar study in which 13,000 patients began taking the drug at the onset of chest pains or a heart attack.
In addition, another study involving 26,500 patients who had previously had heart disease was stopped for the participants who had a history of stroke.
This came after a board of safety expert linked the drug to a higher risk of intracranial haemorrhage in those who had experienced strokes in the past.
Meanwhile, research published in the British Medical Journal, found that powerful painkillers such as ibuprofen can increase the chance of death from stroke or heart attack.
The drugs known as non-steroidal anti-inflammatory drugs (NSAIDS) along with newer ones known as COX-2 inhibitors are known to have an effect on the heart.