Richard Gottshalk, a University of Montana philosophy professor, faced both physical and emotional pain "of stunning magnitude," according to his wife, Doris Fischer. In court papers, she said he was haunted by an awareness that his body was becoming rigid -- a feeling of being "chained to the bed" or "in prison."
His wife said he suffered panic attacks and claustrophobia, believing he was suffocating as his breath shortened. Gottshalk eventually succumbed on day four after receiving a morphine drip for severe muscle spasms and difficulty swallowing.
The plaintiffs argue that in terminal cases, pain medications often don't work. Bill Clarke, whose friend Janet Murdock is dying of ovarian cancer at 67, will testify that her health is "hopeless and dismal."
"She tried to hasten death by stopping eating and drinking, but dehydration causes mouth and lips intolerable pain," Clarke told Missoulian.com.
"The artificial wetting aids don't work, or she's allegoric to them, and she can't take morphine -- she becomes so demented," Clarke said. "So she resumes taking water, but even small amounts delay death."
If the challenge is upheld, the Montana legislature is poised to follow enactment of safeguards and protections that are in place in Oregon, requiring two doctors and a psychiatric evaluation, if deemed necessary.
The patient must make the request for end-of-life medications twice orally and once in writing and have been diagnosed as having only six months left to live.
According to a report from the Oregon Department of Human Services, 88 prescriptions were ordered and only 54 were used in 2008. A total of 441 terminally ill patients have taken their lives in the 11 years since the state's Death With Dignity law was enacted.
About 98 percent of the people who took advantage of the law were in hospice; nearly 82 percent were dying of cancer, Lou Gehrig's disease or chronic obstructive pulmonary disease, according to state and independent studies compiled by Compassion & Choices.
"I do think that the Oregon model is well-regarded," said Steve Hopcraft, a spokesman for Compassion & Choices. "Every single independent study says it's working well and none of the slippery slope arguments about killing the poor and the disabled. It really hasn't happened."
But Rita Marker, one of Montana's attorneys and the executive director of the International Task Force on Euthanasia and Assisted Suicide, said the Oregon law is a "terrible model," one that asks doctors to document compliance with regulations "after the fact."
"There is such lack of transparency that it makes its statistics unreliable," she said."The actual statistics are questionable at best. The state has no way of knowing if it's accurate information."
"The way it works, it's like 'Let's take all the patrol cars off the highway in California and let people tell us if they follow the traffic rules.' How many people will say I was going 85 and I had three martinis?" Marker said.
According to Marker, the Oregon law "says nothing about suffering."
"When one transforms the crime of assisted suicide to medical treatment, it changes everything," she told ABCNews.com. "It's one more treatment available to the patient at the end of life, as good as chemotherapy or hospice."