Who is legally responsible for "failure to warn?"

There are a lot of things that can happen when you take a medication.  We hope you get better, or stop getting worse.  A great many medications are proven to do just that in most people.  Sometimes something bad happens, sometimes it's very bad.  Example: if you get an anti-nausea medicine given IV and it accidentally goes into an artery instead of a vein, you can lose your arm due to gangrene.  It's a pretty safe medication with very rare side effects (we call them adverse effects officially) if you swallow it or take it as a  suppository.  When you're in the hospital or ER vomiting, you need something by another route, and nobody wants to try a suppository, so you get a shot.  Many hospitals have stopped using this drug and give one that works better but has different risky side effects (I'd probably pick the newer drug for my patients but it would be a hard choice, given the risks of that one too).

BUT then there's the complicated web of who pays for the cost of all that medical care you need? Whose fault is it? Is it anyone's fault that people are human and make mistakes sometimes?  Legally, right now, it can be the pharmacist's fault if we didn't ask you if you had any questions about your medication (in a community pharmacy where you see a pharmacist in person, at least) depending on state law.  It could be the person who gave you the shot's fault.  It could be the hospital's fault.  It could be your own fault if you took something and didn't read the warning labels and information that came with it, or if you didn't ask in the pharmacy for help doing so.  If the bad thing that could happen is something that wasn't listed anywhere on the packaging/in the information sheets that came with your medication, then it can be the drug maker's fault for failing to warn you of the risks of taking that medication. 

In the realm of strange things, the drug company that patented the drug is in charge of preparing a label and information to go with it for the both the patient and the pharmacist.  Anyone selling a generic version of that drug must use the same label and information.  Last year the U.S. supreme court decided that generic manufacturers could not be liable for damages because they didn't make the label, and so any failure to warn wasn't their fault.  It seems to me the logical continuation of this is that the brand manufacturer ought to be liable for the lack of information, but I'm sure this is impossible because the big drug companies fight hard and would make the case that since they didn't make the drug, it was some flaw in the manufacturing that caused the bad thing to happen.  It also doesn't address what happens if nobody makes the brand product at all anymore, and possibly the original patent owning company doesn't exist anymore.

So let's all get together and figure out some better way to do this than suing drug companies to get someone to pay for zillions of dollars of medical care that patients can't otherwise afford.  There must be a solution somewhere.