Me thinks, your problem is that your constitution has to deal with situations nobody thought of it 220 years ago. I´m not in the position to think about it, but I´d say it´s time to reform it. E.g. our Art. 1 says the dignity of every human is untouchable, it´s binding for all state authorities and even in civilian life.
YEt you have euthanazia, don't you.
Nevertheless, now that the big federal government has stuck its nose into the a state issue, a federal law will probably pass sooner or later.