Regular NSAID use may reduce the cardioprotective benefits of aspirin
Reclassification of general sale list NSAIDs as pharmacy medicines
would make it possible for community pharmacists to make appropriate
clinical interventions |
Non-steroidal anti-inflammatory drugs (NSAIDs) may interfere with the cardioprotective benefits of aspirin, according to research (Circulation 2003;108:1191). New data suggest that regular, but not intermittent,
use of NSAIDs may inhibit the effect that aspirin has on reducing the
risk of a first myocardial infarction.
Researchers studied subjects who were participants in the Physicians’ Health
Study, in which 22,071 apparently healthy males took 325mg aspirin or
placebo on alternate days. The number of days per year on which the subjects
took non-aspirin NSAIDs was recorded. A greater than two-fold increased
risk of myocardial infarction was observed among patients who were taking
aspirin as well as regularly using other NSAIDs (on 60 days per year
or more). Intermittent use of NSAIDs was not associated with an increased
risk in either the aspirin of placebo group.
Aspirin is thought to reduce the incidence of first and recurrent myocardial
infarction by irreversible inhibition of cyclo-oxygenase-1 (COX1). Since
aspirin and non-selective NSAIDs both inhibit COX-1, there is potential
for competitive interaction between the drugs. However, the authors note
that bias and confounding factors are possible alternative explanations
for these results. For example, participants who used NSAIDs on more
than 60 days per year had a greater body mass index, a higher prevalance
of diabetes and hypertension and were more likely to be smokers.
Commenting on these findings, Bob Rihal, a community pharmacist from
London, told The Journal that this study could have significant clinical
implications. He said that to enable pharmacists to make appropriate
clinical interventions guidelines would need to be developed, possibly
supported by the National Institute for Clinical Excellence and part
of the National Service Framework for Coronary Heart Disease. He noted
that in order for such guidelines to be implemented, the reclassification
of general sale list NSAIDs as pharmacy medicines would need to be considered. |
