NEW YORK (May 4, 2007 Reuters Health) - Users of marijuana (also called cannabis) who vaporize the drug have fewer lung symptoms than those who smoke it, researchers report.

Based on his research, Dr. Mitch Earleywine said: "The argument that the medical use of cannabis is inappropriate because of its potential to create (lung) problems is now clearly invalid. Regular users of joints, blunts, pipes, and water pipes might decrease respiratory symptoms by switching to a vaporizer."

Earleywine, of the State University of New York, Albany and colleagues note that marijuana smoking can lead to respiratory trouble. However, vaporizers heat cannabis to release the psychoactive ingredients, but remain cool enough to avoid the smoke and toxins associated with combustion.

To investigate what impact this might have, the researchers examined Internet survey responses from people who had used marijuana in the previous month.

Respondents who had cystic fibrosis or asthma or reported oral ingestion as their primary means of cannabis use were excluded, as were those who had inhaled other drugs.

Of the 6,882 marijuana users included in the study, only 152 (2.2 percent) reported vaporizing as their primary method of cannabis use.

However, 100 of these users -- nearly 66 percent -- reported no respiratory problems compared to 56 percent of those who did not use vaporizers.

"These data, in conjunction with previous work," Earleywine said, "reveal that people can use cannabis without fear of respiratory problems."

SOURCE: Harm Reduction Journal, April 16, 2007.

http://www.reuters.com/article/healthNews/idUSCOL46069720070504