I'm presuming you mean voluntary euthanasia, here.
In essence, yes, I do. If you have a right to life, then you have every right to death, should you choose it. But there's loads of attendant problems on the legal and moral sides of it. EG pressure from doctors or family. So the topic is best left as-is, I feel. It happens on occasions, but if it does, it's investigated.
Possibly if the ailment was definitely beyond treatment and the patient was in constant pain,but not to assits someone who ,say,was just deeply depressed,for example> Seems legal euthanasia already exists with the refusal to carry on treating patients who will probably die,even when they wanted treatment