Well, first off, we're not talking bottles and bottles -- just one, the fractional dosage depending on the concentration. Morphine comes in different strengths.
Second, most PALS in the situation Kevin described gradually reduce eating and drinking of their own accord, requiring less intervention at the end.
Third, if a P/CALS contacts the physician and reports significant air hunger, it would seem difficult for a physician to dispute. Contrary to the movies, PALS with air hunger breathe more shallowly and are more restless, but they are not typically gasping for air because they don't have those kind of muscles or strength.
Of course, a new opioid rx will require having seen the patient within the last few months, but air hunger (which sometimes manifests as sudden weakness, depending on how the body compensates) is well-established as the ALS end stage, and likewise often begins without transition from "stable on BiPAP." There is a set point for CO2 buildup that is not reversible.
I am only advocating expressing truths, e.g. "I/she is no longer comfortable and is not breathing as well as she did." If the PALS is not yet on BiPAP, it is also no less than the truth to say that s/he does not wish to take that on, if that is the case.
Again, though even physicians can be unduly concerned about prescribing opioids based on news stories, none have been prosecuted for what we are describing. Admittedly, not all have the courage of conviction to deal with eprescribing and pharmacy systems that may require some "hoops," but for anyone treating a PALS, whether a primary care physician or neurologist, the odds go up.
Fourth, as some here have experienced, there can be a practice of using morphine in small doses early on to ease breathing in advance of overt air hunger. Frequent or severe coughing is often addressed with codeine. So perhaps establishing a relationship with a physician for whom those protocols are familiar would also be an option.
Fifth, it is hard for me to imagine that within a given area, there are no legal options in human medicine. But if there are not, there are other contexts in which it is only truthful to say that someone is uncomfortable and needs more help than they have received.
These are just a few thoughts. Situations differ. If anyone needs creative ideas, I'm always here.
--Laurie