Monday, July 03, 2006

Asprin revisited

Aspirin is probably one of the oldest and cheapest drug in clinical use. It can be used as an anti-pyretic, anti-inflammatory, analgesic and also, since the 80's, as a AMI preventive agent. Recently, the world reknowned Dr John Cleland of Hull, reviewed the data pertaining to the use of aspirin in heart attack prevention, and found to all our surprise, that the clnical evidence for the chronic use of aspirin as a CAD prophylactic agent was minimal. It was more like educated medical guesswork.

There is enough evidence for the acute, short term use of aspirin, maybe for 5 weeks, to prevent heart attacks, but almost no adequate clinical evidence for the chronic use of aspirin. I must say that I was surprised. I am a believer of chronic aspirin therapy for CAD and AMI prevention, for the last 15 years. I always relied on the "Anti-platelet trialist" data and US physician Health Study, but Dr J Cleland pointed out that Anti-platelet trialist, was mainly a meta-analysis and it is poor EBM to base treatment regimes, solely on meta-analysis and small clinical trials. That is correct.

There has not been any large scale RCT on the role of aspirin in primary and secondary prevention of CAD. There is even less evidence on low dose aspirin and CAD benefit. Almost all the trials and meta-analysis were with regular or large dose aspirin. If aspirin is an agent without side-effects, maybe the issue is simpler. But the fact is that aspirin does have known side-effects and quite commonly too, ranging from gastropathy, to cerebral hemorrahge. It is not exactly an innocuous agent. Therefore the benefit of therapy, must be balance with the risk of therapy.

As Dr J Cleland proposed, we may have to re-examine our routine use of aspirin, chronically, for the prevention of CAD.

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