Benefits of Medical Marijuana May Outweigh Risks. By Liam Davenport. medscape.com. June 13, 2016. Medical marijuana users experience significant pain reduction with only minor adverse effects, a new study of cancer and noncancer pain sufferers who had previously tried conventional medications shows. Pesach Shvartzman, MD, Ben-Gurion University of the Negev, Israel, found that using medical marijuana led to significant pain reductions within 4 months. Importantly, more than 85% of patients remained on the therapy for the course of the study.

"Monitoring of medical cannabis use is essential and will influence the future decision about this scientifically controversial issue," the investigators noted. They reported their research at the 6th International Jerusalem Conference on Health Policy.
In Israel, medical marijuana is approved for both cancer and noncancer pain, as well as for nausea and lack of appetite in cancer patients, multiple sclerosis, epilepsy, and inflammatory bowel disease, among other conditions.
There are now 23,000 licensed users of medical marijuana in Israel.
"Although medical cannabis has been legal for a decade and is licensed to patients to relieve pain and other symptoms, there has been no information about the users themselves," Dr Shvartzman noted in a release.
To investigate further, the researchers prospectively followed all patients newly licensed for medical cannabis use. The patients were contacted before starting treatment and were interviewed from 1 to 3 months after the date of approval and then every 4 months for 2 years.
The current analysis focused on patients receiving cannabis for a pain symptom. Data were gathered on factors such as the patients’ sociodemographic and disease profile, previous treatment, method of administration of cannabis, exposure, and dose of cannabis.
The team interviewed 213 patients who were receiving medical marijuana. Of these, 65 were cancer patients. In 99.6% of cases, the patients had sought a marijuana prescription after finding conventional medications ineffective; 56.0% were seeking medications with fewer side effects.
Adverse effects with medical marijuana were reported by 79.9% of cancer patients and 67.1% of noncancer patients. The most common effects were hunger, dry mouth, elevated mood, and tiredness. At the first interview, 9% of patients reported that they had stopped taking medical cannabis; 6% reported having stopped at the second interview.
At 8 months’ follow-up, 79 noncancer patients were interviewed regarding their level of pain in the past 24 hours. They reported a significant decrease in the worst pain reported in the past 24 hours, from 8.5 ± 1.6 before treatment to 7.1 ± 2.7 at the first interview and 6.7 ± 2.8 at the second interview (P < .0001).
The study received no funding. The authors have disclosed no relevant financial relationships.
6th International Jerusalem Conference on Health Policy. Presented May 23, 2016.