OTOH, we have all these sentencing guidelines and mandatory minimums and so forth that make people really reluctant to do the testing or receive the testing. I bet we can fix that. Here's a rough idea of what I have in mind.
Currently, if you are at a traffic stop because the officer thinks you are driving dangerously, they're gonna do field sobriety testing: breathalyzer, blood test, walk a straight line type of thing. The testing is sometimes declined by the driver, out of concerns about that producing irrefutable evidence in a later court case. And sometimes the testing is refused because the driver is sleep driving or drugged out of their mind and doesn't even know it, because of medication error or because of non-consensual drugging. _You get to refuse the testing that will clear you_, even if you are not actually conscious. That seems like a problem.
Instead, we should quit requiring consent to _test_. We should instead replace it with consent for the police to access the results of testing. The person who was testing would always have access to the test results. The police could only get access to those test results if the person tested agreed WHEN THEY WERE DEFINITELY SOBER/awake/conscious.
That should dramatically improve data collection on medications that had weird side effects (ambien, some antidepressants + small amounts of alcohol in some people) AND non consensual drugging. You'd still have the problem of whether the drugged person took that drug on their own or were drugged involuntarily and without their knowledge, but at least you'd know what was in their system, and that it wasn't just two cosmos or margaritas or a scorpion bowl or whatever.
Not that you should be driving after any of those, either, but you know what I mean.
Same rules would apply if, not at a traffic stop, but at an ER or something, someone showed up acting very altered. You don't get to refuse the drug test; you do get to choose (WHEN YOU HAVE RECOVERED, or after your health care proxy or guardian or parent or whatever has shown up to sign for you) whether those results are shared with anyone other than you.