Liver Transplants

The pain is debilitating. The only option: smoking medical marijuana. That's the reality for many hepatitis C patients whose road to health includes a liver transplant. Although Canadian transplant centres are more willing than those in the United States, not everyone says yes to liver patients who smoke marijuana, and a University of Alberta researcher says that decision-making process is unacceptable.

Karen Kroeker, along with three other students at various universities, sent out surveys to a number of transplant clinics across the United States and Canada. Results found that the difference between the two countries were obvious in some patient groups: around 60 per cent of Canadian centres would either do the surgery or consider it for a liver transplant patient who smoked marijuana, while 70 per cent of U.S. transplant programs said absolutely not. Kroeker also found that patients in both countries, who have no social support - meaning they have no family, friends or a social worker - aren't likely to receive the organ they need.

The problem Kroeker has with these results: the lack of literature to support the surgeons' decision. As a result of her findings, which will be published in the November issue of Liver International, Kroeker says physicians need to determine eligibility criteria for liver-transplant patients that pertains directly to the likelihood of a patient rejecting the organ and is based only on empirical medical evidence.

When a patient is being reviewed for eligibility, whether they smoke marijuana shouldn't be a factor, she says. "If we have evidence to say the patients don't do well, then I think that's a reason to exclude people," Kroeker said.

She cites alcohol use as an example. When transplants first began to be performed, those who drank alcohol weren't eligible for a new liver. Kroeker's study found, however, that surgeons conducted studies on the topic of abstinence and liver health and, as a result of that research, transplant rules changed. If the patient has been sober for six months, 94 per cent of the clinics in North America will now consider transplantation.

The same goes for HIV-positive patients. "When they first started transplanting, HIV was an absolute contraindication. No one even considered transplantation because the disease was a death sentence at that time." Kroeker adds that's no longer the case and that there is research being conducted on post-transplant HIV-patients that will help determine the viability of transplants in HIV-positive patients.

In reference to her findings, Kroeker said, "I think there should be a large-scale study," because too-little research is available on post-transplant patients whose eligibility may currently be in question.

"Unless you actually perform transplants for those people, how would you know how they do?"

----------------------------
Article adapted by Medical News Today from original press release.
----------------------------

Source: Quinn Phillips
University of Alberta

The Brain on (Lots of) Marijuana

By Sarah Baldauf
Posted June 2, 2008

Marijuana's effect on the brain is far from understood, but Australian research published Monday in the Archives of General Psychiatry suggests that very heavy long-term smoking might be associated with structural changes in two areas of the brain rich in receptors to the drug. The hippocampus, believed to regulate emotion and memory, and the amygdala, which plays a role in aggression and fear, were smaller—12 percent and 7 percent, respectively—in a group that smoked at least five joints daily for at least the past 10 years (and, on average, 20 years) when compared to a nonsmoking group.

Users also showed more signs of sub-threshold psychotic symptoms compared with those in the group that abstained. And on tests of memory and verbal ability, they performed more poorly. "Our findings suggest that everyone is vulnerable to potential changes in the brain, some memory problems, and psychiatric symptoms if they use heavily enough and for long enough," says lead author Murat Yucel of the ORYGEN Research Centre and Melbourne Neuropsychiatry Centre at the University of Melbourne. Pot has been in the news lately for other reasons, too: a government report on a possible connection between pot smoking and depression and also the possible link between heart disease risk and marijuana use.

But it's way too early for parents to conclude that pot deteriorates the brain, cautions Scott Swartzwelder, professor of psychiatry and behavioral sciences at Duke University whose own research focuses on substance abuse and the adolescent brain. "Scientifically, it's a very limited set of data," he says. The study was tiny—it covered only 15 pot smokers and 16 abstainers—and looked at extreme behavior, so "I'm not sure how relevant it is to the general public," says Swartzwelder, who is coauthor of Just Say Know: Talking to Kids About Drugs and Alcohol and Buzzed: The Straight Facts About the Most Used and Abused Drugs From Alcohol to Ecstasy (an updated third edition is being released in August). An earlier U.S. News story looked at some of the science on pot and how it relates to the developing brain.

Yucel acknowledges that the size of the group is an issue, noting the difficulty of finding subjects who smoked a lot of pot but didn't also do other drugs or have medical or psychological issues. Another unanswered question, says Swartzwelder, is the importance of the size of a person's hippocampus and amygdala. "It's tempting to say smaller is worse, but that's a trap. You don't know with any degree of certainty that these pot smokers didn't have smaller brain structures to begin with—maybe they have smaller hippocampus and amygdala, and that's what motivates them to smoke pot in the first place."

An important unaddressed question from parents' point of view is whether the brain differences were a result of how long the men had smoked or how young they were when they began smoking regularly. "We know the younger brain is still maturing and therefore generally more susceptible to the harmful effects of drugs," Yucel says. Emerging research about marijuana, says Swartzwelder, suggests that the drug may have far more powerful effects on the teenage brain than on that of an adult.