Sunday, August 19, 2007

The best medicine?

In discussions of health care prioritisation it is not uncommon for people to suggest that a list of basic treatments, the best medicines for certain conditions, be established and that these should be publicly provided. This is sometimes known as the basic package approach.

Indeed, some see this as the role of the National centre for Clinical Excellence (NICE) here in the UK. In this post I am going to argue that, due to the complexity of medicine, humans and our limited understanding of their interactions that this is an unhelpful viewpoint to take.

The effects of particular treatments for particular conditions with particular people are to some degree unpredictable. While we do understand to some degree how certain drugs work much of our evidence in regards to effectiveness and efficacy of medicine is based on randomised clinical trials which provide a population measure of effectiveness rather than an individual measure of effectiveness. Each individual is very complex and how they react to individual medications is likewise complex.

To give just one example of this from my own experience with Kerry, my first wife who had cystic fibrosis : Kerry was allergic to Panadol, if she had half a Panadol her temperature would drop rapidly (over a 15 minute period her temperature dropped from 39 degrees centigrade to 35!). Since supposedly the only active ingredient of Panadol is 500mg of paracetamol, she was presumably allergic to paracetamol even in small doses since she was only having half a tablet (250mg). However she could tolerate and did take Di-gesic which had more than the amount of paracetamol (325mg) as half a Panadol along with dextropropoxyphene hydrochloride (32.5mg) with no allergic reaction. Even more puzzling lest we think the dextropropoxyphene hydrochloride had some prophylactic effect, when the NZ government switched from funding Di-gesic to funding Paradex, a cheaper generic drug with exactly the same active ingredients as Di-gesic she had precisely the same allergic reaction she had with Panadol.

The net implication of this is that while some treatments may usually be low yield, with some conditions, for some patients they will be high yield. Likewise while some treatments may usually be high yield, with some conditions, for some patients they will be low yield and alternative strategies will be preferable. Furthermore individual patients may have co-morbidity and be on other medication for that co-morbidity. This has two effects. Firstly, the chemical interactions with the body become even more complex which makes it harder to predict what the likely outcome is or indeed to even determine what it was. This is particularly problematic with people with serious illnesses who are often on many different medications; Kerry for example at one stage was taking twenty two different medications daily. Secondly, this means that some standard treatments may have to be avoided for some patients because they are already on medication which is contraindicated for co-usage with the standard treatment for their health condition. Thus different treatments for the same condition will be appropriate for different patients.

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