Children, like women, are somewhat disenfranchised from the system for the same good reason initially: to avoid testing drugs on children, women, and unborn children is probably a good ethical boundary to adhere to at some point. Unfortunately, that means these populations are largely untested when drugs enter the marketplace.
I don't believe we can determine drug effectiveness and safety without post-market surveillance. It can't happen earlier. Clinical trials give us an idea of where drugs can be used safely and effectively, but actual use in large, diverse populations gives us our true understanding of where they're most valuable.
For children, it's equally important that we understand the scientific determinants of drug response. The difficulty in all of the discussions we're having this morning is heterogenity of response. For every one person who doesn't respond to a therapy there are three who do, and vice versa. For every five who respond well there's one who has a serious and permanently disabling adverse reaction. It may be fewer than one; I'm not using actual numbers here. I'm just suggesting there is wide variability. At the clinical level, we're constantly faced with what's going to work, what can we try, and what would be best to use.