Like let’s say I want to develop a better antidepressant. Where do I start with that, if I’m the R&D department?
There are generally 2 main methods of drug discovery. In the first, you figure out a way to test new chemicals in a chemical method (like does compound X kill bacteria at very loe concentrations and not kill human cells at all). There is a large amount of testing done, and then it is moved to an animal model (usually mice). Tons more testing in several different animals and lots of human cell lines. Much later it will be tested on super low doses in humans and follow the rest of the FDA drug approval process.
The other takes a slightly more informed view. If we know that a disease is caused by some sort of chemical marker or protein in the body, we can use computers to calculate if the chemical will affect that chemistry in the body. If it passes the computer test, it can move on the the chemical tests and then through the rest of the cycle.
Basically, yes, we throw a bunch of chemicals at a problem until one looks good, but we do a lot of testing before we ever move to animal studies. A drug discovery person could (theoretically) work their entire life and never have a compound move from chemical tests (assay) to animal model. This is why it is so expensive…..IT IS FREAKING DIFFICULT!
ShitInMyCunt-2dollar: Many drugs start with a known ‘skeleton’. Take the classic opioids/opiates as an example (morphine, heroin, codeine, thebaine, etc). They all have a core structure that is the same.
So you take that structure and ‘join things’ to it (or maybe remove things). A methyl group here, a hydroxyl group, there (aka – functional groups). Now you have something that is likely to behave in a similar fashion, but you don’t know how strong/effective/toxic it may be. So you do a huge amount of testing to find out, well before you ever give it to a human.
That’s a really simplistic explanation, but you get the idea.
timb0sIice: They know the general receptor structure they’re trying to effect, analogues will have varying levels of effectiveness once broken down by the body.
Heroin is converted to morphine for example
grum_pea__: Another method is to learn from indigenous ‘medicine men’/herbalists and take inspiration from plants secondary metabolites.
barcabarn: $$$$$. Industry funds research, academic communities largely co-mingle with necessary funding sources that do serve purposes. Bigpharma is in the business of $, chronic drugs that treat (not heal) large populations will take priority over smaller market cures that may be more scientifically attainable every time. Read the book Blood Medicine if your interested in a true story about pharmaceutical salesmen whistleblowers on the off-label usage of Amgen for cancer patients, worthwhile insight there.