A couple months ago I got hit with a fun new, super painful, rare skin condition and I was seeing all kinds of specialists for it. One specialist prescribed me one thing, and then a couple weeks later another specialist prescribed me something else - he knew what the other specialist had prescribed and said to just take both until I saw the other specialist again and he could decide if I should continue with his prescription.
But when I went to the pharmacy the pharmacist was getting me my prescription and he brought out all this paperwork and said I needed to fill out all these disclosure forms saying that he had let me know of the lethal combination of the different prescriptions. He said that the 2nd prescription could increase the potency of the first so that it becomes lethal. But he still let me take both of them, just as long as I signed the paperwork.
So yea, that was a fun trip to the pharmacy!