I guess I should have made myself clearer. Chemistry is absolutely an essential component of biological science. In saying that biology has emergent properties that can't be fully explained through chemistry, at least not in practice, I'm not saying that biologists abandon chemistry just as chemists don't abandon physics. They're still there, they just aren't enough. Life is all about chemistry. Cells are little chemical factories of astonishing complexity. However, multicellular organisms like you are about more than the chemistry that animates your cells. That means that studying them requires methods and expertise that you don't learn getting your chemistry Ph.D. On the other hand, getting your biology Ph.D. does require learning a lot of chemistry.
Of course there is a whole lot more to biological science than biomedicine, but for the sake of brevity I'm focusing on biomedicine and specifically drug development, because we're making an example of Linus Pauling and that's where he got into trouble. (Don't worry about his feelings, he's dead.) As I've said, before beginning to investigate a potential treatment in humans, it's highly desirable to have a biologically plausible hypothesis about how it will work. That isn't always absolutely essential -- some drugs have been investigated because there is strong anecdotal evidence that they seem to work. But contemporary ethical standards do require that there be a reasonable determination of safety in animal models before giving substances to humans.
Companies that hawk "supplements" without FDA approval often tout clinical trials, but they are typically of low quality and don't meet the standards for acceptance by the medical community, let alone FDA licensing. What I'm going to offer now is an outline of the standard process for investigational drugs.
Once we've gotten past the rats and guinea pigs, the first step in humans is Phase One trials. These are not intended to provide evidence of efficacy, but only address safety and better understanding of what happens to the chemical in the body. They typically use from 20 to 100 "volunteers," but they aren't really volunteers because they are paid. They're usually healthy -- they don't even have the target disease, although sometimes they are seriously or terminally ill. In the latter case, if it really is a miracle cure, you might see evidence of efficacy. (That did happen with some HIV drugs, and a cancer drug called Gleevec.)
The purpose of a phase one trial is, first, to establish a safe dosage. This means starting with very small doses and gradually increasing to see when and if people experience adverse effects. The second purpose is to determine "pharmacokinetics" -- how the drug is metabolized, how quickly it is eliminated (usually by enzyme systems in the liver) and what the breakdown products are, as these may be harmful to some people and not others.
Commenter CP wonders whether prisoners might be offered a chance to "volunteer" for such studies in return for credit. That has been done in the past, but is now considered to be ethically highly dubious at best. It's questionable whether prisoners, who by definition are already under duress, can really be considered to be freely volunteering. Historically, many experiments on prisoners were clearly unethical and took far too little consideration of their safety and welfare. Currently, experiments using prisoners are unlikely to be approved by the Institutional Review Boards that oversee the ethics of human subjects research. That can be debated, but it's where things stand now.
Next time, Phase Two trials and the challenges of making inferences about efficacy.
No comments:
Post a Comment