Taking common anti-inflammatories such as ibuprofen for only a week can significantly raise the risk of having a heart attack, a study suggests.
Patients are being urged to limit their use of the painkillers to as short a period as possible after they were linked to increased heart attack chances of more than 50 per cent.
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Scientists already suspected a connection between potentially fatal cardiac events and non-steroidal anti-inflammatory drugs (NSAIDs), which include ibuprofen, diclofenac and naproxen.
But there was uncertainty as to how long a patient could take the drugs before putting themselves at added risk.
The new investigation, the largest of its kind, found anti-inflammatories might boost the chances of a heart attack as early as in the first week of use. They found a particularly strong connection within the first month.
Published in the British Medical Journal, the study urges doctors to weigh up risks with the benefits of prescribing the drugs.
Because of the observational nature of the research, which examined the prescribing data and health outcomes of more than 446,000 people, scientists cannot say for sure why anti-inflammatories are linked to greater heart attack risk.
Previous research has suggested the connection may involve the drugs blocking a hormone called prostacyclin, which protects blood vessels.
![Nurofen is the most common brand of ibuprofen, which has been linked to an increased risk of cardiac arrest.](/web/20170513011253im_/http://www.watoday.com.au/content/dam/images/g/v/0/2/g/u/image.related.articleLeadwide.620x349.gw15yl.png/1494381513454.jpg)
Dr Mike Knapton, associate medical director at the British Heart Foundation, said: "This study worryingly highlights just how quickly you become at risk of having a heart attack after starting NSAIDs.
"Whether being prescribed painkillers like ibuprofen, or buying over the counter, people must be made aware of risk and alternative medication should be considered where appropriate."
The research team from Canada, Finland and Germany said there was "a rapid onset of risk" for heart attack within the first week of use, while the risk was highest during the first month of taking the painkillers.
However, using the drugs for longer than one month did not increase the risk any more compared with shorter use.
The added chances of a heart attack were more pronounced among users on high doses of the painkillers. Use for between eight and 30 days at a high dose was "particularly harmful".
Overall, a person's chances of having a heart attack in any given year while taking anti-inflammatories is 1 per cent, the study found.
Professor Jane Mitchell, head of cardiothoracic pharmacology at Imperial College London, said: "These painkillers include some of the most commonly taken drugs worldwide and, although the increased risk of heart attack might be low, because of the scale of their use it is seen as an important problem."
Scientists have stressed the study does not prove a causal link between painkillers and heart attacks as there may be other linking factors.
For example, the increased heart attack risk may actually be caused by the complaint prompting a person to take painkillers.
Telegraph, London