Not all patients, especially those with digestive disorders, are able to consume and digest fatal pharmaceutical cocktails prescribed by doctors.
An injection would have to be the necessary vehicle to end life:
Silent Terror: Un-peaceful Paralysis
"In Canada, the majority of assisted suicide is done via an injection of substantial dosages of the anesthetic agents propofol, midazolam, and the paralytic rocuronium. Propofol and midazolam are likely not the cause of death. Instead, it is most likely the rocuronium, leading to death by muscle paralysis. Once paralyzed, MAID deaths will appear outwardly calm and peaceful. However, this is essentially death by asphyxiation. The U.S. death penalty commonly uses an intravenous cocktail known as lethal injection. This cocktail is strikingly similar to Canadian MAID. Studies show lethal injection can cause rapid accumulation of fluid in the lungs -- prisoners feel they are drowning as they die. Far from dignified, death by MAID may be highly distressing."
-Joel Zivot is an associate professor of anesthesiology/surgery at Emory University and a senior fellow at the Emory Center for Ethics
https://www.medpagetoday.com/opinion/unchartedterritory/113550
Dr. Zivot's Ted Talk: Medical Assistance in Dying Not as Easy at is Looks:
AP Investigation: Experts: Canada euthanasia law devalues disabled:
See also for comparison:
https://eji.org/news/lethal-injections-cause-suffocation-and-severe-pain-autopsies-show/
