First, I want to agree with @anongoodnurse
There is debate and mixed views inside the "Western Medical Community" which is a vast, vast group of people.
I wanted to expand on that by pointing out the US government has put a National Institute of Health center together to study what is academically known as "complementary and alternative medicine (CAM)." CAM is basically a catch all for what may be a homeopathic or traditional medicine in any particular location, but paired with modern scientific thinking. The name of the NIH center is the "National Center for Complementary and Integrative Health."
I think a very approachable editorial on what exactly they do was written by a previous deputy director. They represent a growing field of research that applies rigorous logic and scientific testing to alternative medicines. In other words, they use "traditional medicines" as a starting point to drive new modern interventions.
The general premise goes something like this:
1) Community A has traditionally used [Plant/Intervention] B to address disease or symptoms X, Y, and Z.
2) Some aspect of B may infact be pharmacologically/physiologically active.
[Note the null hypothesis can also be, and often is, true; that B provides no benefit over placebo or sham operation.]
3) Break down B into it's molecular or procedural components B[1,2,..n]
4) Compare B components to known interventions to make educated guesses as to what really is going on.
5) Test basic components of B, B as a whole, and mixtures of B components (derived from educated guess) to address X, Y, Z, preferably in an animal model first.
6) Refine positive results into traditional medicine drug/intervention M
Cannabis provides a good example of how this can be done.
NOTE: I make no stance on the legalization of cannabis in the US for recreational use, and could see it go either way. I think that a honest conversation about medical vs recreational use should be had, and that medical uses should not drive something that is desired for recreational uses. Please don't derail this post on merits or demerits of cannabis use.
The study of cannabis lead to the discovery of THC the principal psychoactive component of cannabis. This lead to the discovery of medical benefits of THC, and the ability for physicians to use THC in drug form dronabinol (brand name Marinol).
In our example cannabis would be our [Plant B], nausea and loss of appetite our symptoms X-Y, cannabinoids our components of B, and Marinol the final drug produced M.
I include the following note/disclaimer because 1) it shows my point of view on the question asked, and 2) it will hopefully cut of some comments I suspect are likely to come from such a post.
As I'm sure it will come up, it certainly could be true that additional cannabinoids will come up to be medically significant, perhaps in certain combinations, and that may require inhalation as a delivery route. I'm happy for that research to be conducted, and I wait to see what comes out as scientifically valid.
I note that burning and inhaling of a raw plant, with all the chemicals that are produced in the process, is not something I would recommend to any patient. That goes from tobacco, to cannabis, to grass clippings. We have nebulizers to aerosol drugs that need to be inhaled.
This is where taking traditional medicine as a start, and then advancing it to "Western Medicine" comes in. The scientific method has born out in pharmacology, and needed active ingredients from plants/animals can be identified, derived, purified, and normalized so that they can be safely and consistently applied in "Western Medicine" (which can be called "traditional" by the people practicing it).