is it generically safe to take one 1mg kpin and one 2mg xan? i'd say that 99% of the population, using and non-using alike could safely take those two drugs at the same time and be fine.
now, up the dosages to something outrageous and add some alcohol and you've got yourself a trip to the er. but it wont be because of drug interactions, it will be because you've consumed an unsafe total quantity of a depressant.
f'rinstance, if you took say 100mg of xanax and a .5mg k-pin, chances are good that unless you've got a decent tolerance, you'll be waking up in the hospital - if you wake up. but it won't be cause of that little bit of klonnie that you mixed in there.
ultimately no drug used beyond its express purpose is truely safe. hell, many drugs that are used as prescribed aren't safe.
its never the drug, its always the user.