Jane McCredie: NSAID safety issues expose flaws in our drug monitoring

NEW DRUGS have to jump through all sorts of hoops to get approval for marketing in Australia, but once they’re out there, it’s a different story.

Experts have been calling for a more coordinated system for monitoring drug safety in Australia for years – and particularly since the September 2004 withdrawal of the selective COX-2 inhibitor Vioxx over concerns about cardiovascular risk – but we’re still waiting.

The cardiovascular safety of NSAIDs was back in the news last week after a large Danish observational study conducted in healthy individuals found that various NSAIDs were associated with an increased stroke risk – from 28% for ibuprofen to 86% for diclofenac.

The study correlated NSAID use and stroke data in half a million people aged over 10 years, controlled for age, sex and socioeconomic status. Those with chronic diseases or a hospital admission within the previous 5 years were excluded.

Cardiologist Gunnar Gislason, who presented the data at the recent European Society of Cardiology Congress, called for NSAIDs to be available only on prescription in light of the findings.

It’s no accident this new data came from Scandinavia, where postmarketing surveillance systems allow linkage of prescribing data to other information, including hospital admissions and mortality figures.

If similar effects are associated with the drugs here, we quite simply have no way of knowing about them.

Observational studies like this latest Danish one obviously don’t prove cause and effect, but they can provide an effective warning system for real-world adverse effects that would be unlikely to show up in premarketing clinical trials.

You don’t see many drug trials conducted in elderly people with multiple comorbidities, for example, yet those are precisely the people who are likely to be the biggest users of most pharmaceuticals – and the ones at most risk of adverse effects.

Safety data for these groups generally only become available after the drugs hit the market, and we, in Australia, basically don’t bother collecting it.

Yes, there are potential privacy concerns when you start talking about linking data from various parts of the health system, but they’re not insurmountable.

Surely it’s time we paid proper attention to the safety of medications after they’re released into the general population as well as before?

Jane McCredie is a Sydney-based science and medicine writer. She has worked for Melbourne’s The Age and contributed to publications including the BMJ, The Australian and the Sydney Morning Herald. She is also a former news and features editor with Australian Doctor magazine. Her book, The sex factory, on the science of sex and gender will be published by UNSW Press later this year.

Posted 20 September 2010