From Mayo Clinic
Marijuana-derived drug less effective than standard drug for improving appetite and weight in patients with advanced cancer ROCHESTER, MINN. -- A drug derived from marijuana is not as effective as a standard drug for curbing loss of appetite and weight in patients with advanced cancer, according to a study conducted by Mayo Clinic in Rochester, Minn., and the North Central Cancer Treatment Group (NCCTG). The results of the study are published in this month's Journal of Clinical Oncology.
This first-of-its-kind, large multi-institutional study found megestrol acetate, a standard drug for treating loss of appetite and weight in cancer patients, to be more effective than dronabinol (brand name Marinol®), a drug derived from marijuana. The study also found that there was no notable benefit when both drugs were given together.
"Anecdotal reports and previous small studies suggested that marijuana and its derivatives stimulate appetite," says Aminah Jatoi, M.D., a Mayo Clinic oncologist and researcher on the study. "Our study found that dronabinol, in the doses prescribed in this trial, doesn't hold up to standard treatment with megestrol acetate."
"These findings should dampen enthusiasm for using marijuana derivatives for this purpose," Dr. Jatoi (ja 'toy) added.
Seventy-five percent of the patients in the study taking megestrol acetate reported appetite improvement. This compared with only 49 percent of patients taking dronabinol reporting appetite improvement. Further, 11 percent of the patients on megestrol acetate, compared with only 3 percent on dronabinol, gained more than 10 percent of their baseline weight.
Loss of appetite and weight is a major problem, affecting more than half of patients with advanced cancer. It's also an understudied problem.
"Nobody knows all of the factors that come into play as cancer patients lose weight," says Dr. Jatoi. "This study was an attempt to help cancer patients by finding some answers about what works and what doesn't work for those struggling with eating.
"To our knowledge, this is the first study to compare a standard drug to a drug derived from marijuana in an effort to help cancer patients with this problem," she said.
The study evaluated 469 cancer patients between December 1996 and December 1999. These patients were 18 years of age and older, and all had been diagnosed with an advanced cancer. They also had to have a self-reported loss of appetite and/or weight loss of at least five pounds during the preceding two months.
The double-blinded study randomly enrolled the patients into one of three treatment sections:
* megestrol acetate liquid given 800 mg orally each day plus capsule placebo
* dronabinol capsules given 2.5 mg orally twice a day plus liquid placebo
* a combination of both medications in the dosages noted
Dr. Jatoi noted that megestrol acetate is not the complete answer to stimulating appetite and boosting weight in cancer patients and more research needs to be done to find better drugs.
"But at this time, we can say that megestrol acetate is more effective than dronabinol in the doses we tested," she said.
The North Central Cancer Treatment Group (NCCTG) is an affiliation of 23 community clinics and affiliates in 18 states and two Canadian provinces with a research base at Mayo Clinic Cancer Center in Rochester, Minn.
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