The popular pain killer ibuprofen can knock out the positive effects aspirin has in preventing heart attacks and strokes when patients take both medicines say doctors at the University of Dundee.
Aspirin has been found to have beneficial effects in preventing cardiovascular disease. It makes the blood clotting cells less sticky so they are less likely to form clots causing heart attacks and strokes. However, laboratory research at the University of Dundee suggests that when both ibuprofen and aspirin are taken, the ibuprofen reacts with the aspirin impeding its ability to reduce the stickiness of the blood cells.
Professor Tom MacDonald at the Medicines Monitoring Unit at the University of Dundee will publish his findings in The Lancet this weekend 15/2/03. He explains: "Although our findings are not conclusive, they do support the hypothesis that ibuprofen may reduce the benefits of aspirin in people with cardiovascular disease. Perhaps it would be prudent that such patients took an alternative pain-killer at least until this issue is further clarified."
He continues: "We also know that aspirin and ibuprofen taken together increases the risk of bleeding from stomach ulcers. So this combination may not only reduce the benefits of aspirin, but may also increase the risks of side effects.
We have plenty of data on the efficacy and side effects of drugs when they are tested to get their licence but research that shows what happens when people use a range of drugs at the same time or are suffering a number of different diseases requires detailed research on a large scale."
An American research group recently showed that in a test tube ibuprofen blocks the aspirin from stopping the blood sticking together. They also showed that Non steroidal anti-inflammatory drugs (NSAIDs) did not have this effect in the test tube. If the blocking effect happens when patients take both medicines then the consequence is likely to be that the effect of the aspirin, in potentially extending a person's life to near what it would be if they had no heart problems, would not happen - it would be as though they had never taken the aspirin.
Tom MacDonald and Li Wei from the Medicines Monitoring Unit (MEMO) studied 7107 patients with cardiovascular disease who were discharged from hospital and were taking low-dose aspirin. Within this group they compared the death rate of those patients taking prescribed aspirin alone with those taking prescribed aspirin and ibuprofen.
Individuals prescribed both aspirin and ibuprofen had a double risk of death from any cause and around a 75% increased risk of death from cardiovascular disease compared with those prescribed aspirin alone. There was no increase in mortality risk for people prescribed aspirin in combination with diclofenac or other NSAIDSs.
The research was conducted using anonymised data obtained from the health records of people who live in the Tayside area of Scotland, the only region of the NHS that is able to electronically perform such studies using NHS patients' unique identifier.
The Medicines Monitoring Unit at the University of Dundee has unique technology that allows clinicians to collect, link and analyse anonymous patient data throughout NHS services including primary care, hospital care, pharmacy care and laboratory data in line with the data protection act.
Contacts
Professor Tom MacDonald 01382 633405 tom@memo.dundee.ac.uk
Dr Li Wei 01382 636119 li@memo.dundee.ac.uk
By Jenny Marra, Press Officer 01382 344910 j.m.marra@dundee.ac.uk