I just asked my wife (who's a pharmacist). She says that it's indeed true that drugs companies basically ignore existing drugs because it's not worth the costs

I just asked my wife (who's a pharmacist). She says that it's indeed true that drugs companies basically ignore existing drugs because it's not worth the costs to prove that they work even though they can officially patent them for new usages. Here's an example: https://en.wikipedia.org/wiki/Pregabalin https://en.wikipedia.org/wiki/Pregabalin That's an epilepsy treatment which also worked for nerve damage. They weren't allowed to dispense the generic for nerve problems. However in practise the prescriptions don't include the reason so in practise they provided the generic.