Marijuana to Treat Pain: A Pill May Outlast a Puff
Study shows a pill containing THC lasts longer and may be safer than smoking pot
WebMD News Archive
By Brenda Goodman
MONDAY, April 22 (HealthDay News) -- A pill may work as well as a puff when it comes to using marijuana to treat pain, according to a small but carefully controlled new study. Pain relief from pills may last longer, however, and may not leave people feeling as high as they do after they smoke the drug.
Medical marijuana is now legal in 18 states and the District of Columbia, according to the nonprofit group ProCon.org. Surveys show pain is one of the main reasons doctors prescribe it. But studies testing marijuana as a pain reliever have had mixed results. Some have shown that it works as well as mild opioid (narcotic) pain relievers like codeine, while others have indicated that the drug might actually make pain worse.
To learn more, researchers at the Substance Use Research Center of the New York State Psychiatric Institute pitted two strengths of smoked marijuana against two strengths of the drug dronabinol, which contains tetrahydrocannabinol, or THC, the same active ingredient as in marijuana plants.
Dronabinol has been FDA-approved since 1985 to treat the nausea and loss of appetite that commonly afflict patients with cancer and AIDS. Less is known about its effects on pain.
For the government-sponsored study, researchers recruited 30 healthy, pain-free men and women who were already regular marijuana smokers.
During five experimental sessions, participants took a capsule and then 45 minutes later smoked a marijuana cigarette. The capsules contained either an inactive placebo, or 10 milligrams or 20 milligrams of dronabinol. The cigarettes were specially made by the U.S. National Institute on Drug Abuse, which funded the study. Cigarettes were standardized to contain marijuana with no THC, a low dose of the drug or a higher dose.
People in the study never knew whether they were smoking or swallowing the drug or how strong the dose was. Researchers made sure they never got a double hit of the drug during the same session.
The testing days were spaced at least two days apart, and participants were asked to refrain from smoking the night before their lab visits.
Several times during the sessions, researchers had each person place their hands in a water bath kept just above freezing temperatures. They measured how long it took study participants to feel pain and then how long they were able to tolerate the pain before they yanked their hand out of the water. Participants also answered questions about how intensely they felt the pain during the experiments and how high they felt.
When researchers tallied their data, they found that both the smoked drug and the pill were about equally effective at controlling pain.
After smoking the strongest cigarettes or taking the highest strength of the pill, it took people an average of about 12 to 13 seconds longer to report feeling pain from the cold water compared to when they took the placebos. Both forms of the drug also significantly increased pain tolerance, the amount of time a person was able to stand the pain before they pulled their hand out of the cold water.