I find it weird because there are medications and treatments that help people, but can cause bad reactions in others.
I don't know if it'd kill them, but it seems like a...normal risk.
I didn't die, but when my psychiatrist gave me a new medication, it reacted badly to my other medication and it made me not sleep in over 24 hours which greatly affected my mental stability.
When I told him what happened, he said he'd never heard of a reaction like that from that specific medication.
But the medication apparently helps a lot of other people.