Of course they do

"He is also experimenting with his next project, an implantable switch aimed at people with dementia. The idea is that a person can set the implant to release deadly drugs into their bloodstream in a year’s time if they have deteriorated too much to stop it. The switch would start making a ticking sound, to warn its wearer that the moment it will release the drugs is approaching. If the person cannot remember what the ticking is or how to physically turn the device off, the implant will release drugs that eventually kill them. To test the idea, Nitschke says he plans to implant a test version, with saline solution, in himself once the prototype is ready."

Of course they do