is sufficiently difficult that mere error isn't generally considered a matter of culpability unless it's accompanied by negligence or recklessness
In other words: medicine is based on imperfect information, it's impossible to correctly diagnose and treat anything, and people should stop expecting doctors to get everything right and focus more on getting things less-wrong.
I'm a fan of exploratory pharmacology, although I don't know if that's considered ethical. I don't particularly care, so long as it's safe.
I went in for psychiatric care due to ADHD, and eventually discovered my insomnia was severe (I thought I was getting 6.5 hours; I was getting ~2 hours for over a year). I don't have attention issues when well-rested; I'm fidgety and have impulse-control problems. That means my ADHD is inattentive-type when sleep-deprived and hyperactive-type when well-rested. I've also determined the original issue (starting things, working for a few days or weeks, then never finding the motivation to continue) is rooted in anhedonia, and is textbook major depressive disorder even though I don't feel depressed.
So here's the fun part.
My first try was Modafinil, because I did not want amphetamine, because I knew I had sleeping issues. Modafinil worked great, and then messed me up bad (extreme depression) after two weeks. I went back and checked out how I was really sleeping for the prior several months and determined my FitBit was reading me as asleep when lying in bed for hours awake; switched to the Sensitive tracker those days and it read my sleep time accurately--at damned near nothing. Yeah, don't use Modafinil to stay up for 2 weeks straight; and don't use Modafinil if you otherwise don't sleep for 2 weeks straight.
I had tried Phenylpiracetam (not scheduled, not approved; NDRI) to no success prior to getting a psychiatrist, but only did that for a week because it made me really high. A talk with my psychiatrist determined that "really high" was pretty much "there are these feelings when good things happen and I've never felt this before and it's a euphoriant and I'm high as shit!" I told him I needed to get some counseling and figure out if that's anhedonia or just me being high, and he asked a bunch of questions and determined ... it's anhedonia. Put me on Amphetamine.
Did not like Amphetamine.
Amphetamine hits me really hard. At 10mg XR it makes me anxious and depressed; at 20mg XR it causes severe overdose symptoms (I pissed brown and lost 6 pounds in one day, including muscle mass); at 15mg XR the anxiety goes away and I feel mildly depressed. If I take one, I don't sleep for at least 26 hours. I stopped taking them while taking Belsomra (Suvorexant), which allowed me to sleep but didn't make me tired.
Belsomra is hard to get covered by insurance, so I tried Eszopiclone. I was high as shit 24/7 and nearly drove my car into another car 20 hours after the last dose, but it didn't help me sleep. 12 days in I stopped taking it, went through really bad withdrawal for one day, and decided GABA drugs are not for me. To hell with that.
It goes on and on. I've determined serotonin drugs are not a thing for me--that means all those SSRI anti-depressants are a no-go. SAM-e (at 800mg) and Atomoxetine (at 80mg) both cause serotonin mania; Atomoxetine at 60mg causes serotonin-related problems (tachycardia, fatigue) that go away at a split 25mg dose. Atomoxetine is an SNRI that primarily occupies NET; once NET is 98% occupied, an increase in dose rapidly occupies SERT and jacks up the level of Serotonin in your brain. I like Atomoxetine at lower doses, as it eliminates the excessive poor behavioral impulses and leaves me with something I can control; it also allows me to sleep, so I don't need any sleep drugs.
I've been pushed into suicide-grade depression, driven insane, and outright poisoned. As a patient, I can handle it: I'm extremely psychologically-resilient and have a strong tendency to dissociate, so even side effects like suicidal impulse (as opposed to just ideation or fantasies of self-harm) are generally harmless to me. That means I can take a rapid battery of switching out various drugs, while less-resilient patients will need a higher degree of caution and monitoring--which is how psychiatric care is approached now anyway.
My point, however, is that these limits don't just outline what to do in earnest attempt at treatment. If the doctor wants to give me a drug as an exploratory measure to get a better understanding of what's going on in my brain, I'm up for it. I've learned serotonin is no good for me. I've learned dopamine will keep me awake, but small amounts of the right NDRI will enable my rewards mechanism and operant behavior so I can self-activate. Each failure reveals a little information; information is valuable in a field where literally nobody has any clue what they're doing.
The doctor can't crack my head open, point out where I need dopamine and norepinephrine, and give me a drug to give exactly the right amount of dopamine and norepinephrine in the right places. One NDRI will give me depression and anxiety; another will make me respond to rewarding stimulus by reinforcing my behavior (having almost no reinforcement response is really bad, by the way). They don't actually know precisely what's wrong with you; they have a list of patterns that tell them what might be wrong with you and what might help, along with what those things do. Can't blame them for getting it wrong before they get it right.
Surgeons can't know what your CNS is going to do when they poke you; you might go into cardiac arrest at any time. You need sedation. You might have an allergic reaction to a drug and die. You get cancer and you appear to have the flu, but it gets worse. Biopsies and other screens show false-negatives and may say you're clean for cancer. It's really hard to separate out one set of conditions from another when the information you have tells you it's 37% likely X is wrong, 29% likely Y is wrong, 21% likely Z is wrong, and so on.
Some doctors are in way over their heads and need a second opinion, and should know better. Some doctors just don't give a shit, and should be hanged. Pretty much every doctor you encounter actually has no earthly idea what's going on, and is doing the best job possible with the full breadth of collected human medical knowledge. Unless you have a broken bone, don't expect them to identify the problem correctly 100% of the time.