Calls for caution over findings in NSAID heart study
Use of prescribed ibuprofen, diclofenac or rofecoxib is associated with
an increased risk of myocardial infarction, according to a study in last
week’s BMJ (2005;330:1366).
Commentators have warned, however, that the study should be interpreted
with caution.
Ibuprofen was associated with a raised heart attack risk in the
BMJ study |
A total of 9,218 patients, who were taking non-steroidal
anti-inflammatory drugs in primary care between 2000 and 2004 and who
had a first diagnosis
of MI during the study period, were matched with 86,349 controls. The
researchers found that use of ibuprofen within the past three months
was associated with an increased risk of MI (adjusted odds ratio 1.24,
95 per cent confidence interval 1.11–1.39), as was use of diclofenac
(1.55, 1.39–1.72) and rofecoxib (1.32, 1.09–1.61). An accompanying
editorial,
however, suggests that the quality of data on cardiovascular risk factors
and other potential confounders was poor and so the ability
to control for confounding may have been limited.
Commentinting on the study, David Pruce, director of practice and quality
improvement at the Royal Pharmaceutical Society, said the evidence presented
does not justify the conclusion that an increased risk of MI is associated
with NSAID use. He added that such “nested” case control
studies are fraught with difficulties, since it is difficult to match
the two groups being compared. “The study in the BMJ could not
match patients in the study group and the control group well enough because
data on smoking and obesity were missing in between 13 per cent and 28
per cent of patients. This alone could confound the results.” He
added: “The study highlights that there needs to be some robust
research to determine whether there are actually increased risks associated
with NSAIDs. However, this current study does no more than raise the
question.” Mr Pruce is advising patients not to stop taking NSAIDs.
The Medicine and Healthcare products Regulatory Agency is currently reviewing
the cardiovascular safety of traditional, non-selective NSAIDs. “In
the meantime, prescribers should note existing Committee on Safety of
Medicines advice regarding the use of anti-inflammatory medicines, in
particular that the lowest effective dose should be used for the shortest
period of time necessary,” a spokesman said.
Meanwhile, two additional studies contribute to evidence surrounding
cardiovascular risk and use of NSAIDs. A retrospective cohort study in
patients with congestive heart failure reported in the BMJ (ibid, p1370)
found lower mortality in patients treated with celecoxib than in those
treated with rofexocib or traditional NSAIDs. A study involving 650,590
patients with arthritis, presented at the European League Against Rheumatism
conference in Vienna, last week, found an increased risk of acute MI
with ibuprofen and rofecoxib. |
The
Pharmaceutical Journal
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