Medical Marijuana: Is it Safe?

Many people have used medical marijuana to manage symptoms of HIV infection and side effects of therapies. Medical marijuana users assert that the drug is useful in treating nausea, increasing appetite or as a mild analgesic (to help with headaches or mild pain). However, people living with HIV have been left with unclear information as to the risks and benefits of medical marijuana use.

A recent study, presented at the Durban Conference, lead to headline news claiming "Medical Marijuana is Safe for HIV Patients." While the study showed that after 21 days the use of medical marijuana did not increase HIV levels, conclusions about the safety of medical marijuana were overstated by the mainstream media.

The study, conducted at the University of California in San Francisco (UCSF) is the first medical marijuana study in people with HIV to be funded by the U.S. Government. Data were presented on 62 people who had completed the 21 day in-patient study. Three times daily, before meals, volunteers received either medical marijuana (smoked/inhaled), dronabinol (Marinol, a pill containing the active ingredient in marijuana) or a placebo. After 21 days there were no differences in HIV levels among those receiving marijuana, dronabinol and placebo. Use of either marijuana or dronabinol resulted in greater weight gain and increased food intake than use of placebo.

Information on the impact of marijuana on CD4+ cell counts and marijuana-HIV drug interactions was not presented. The investigator anticipates this information to be available and presented at a meeting in Toronto later this year.


The study was not designed to assess the overall safety of marijuana use for people with HIV, contrary to the implications of the media headlines. Safety of a drug needs to be established through much longer studies looking at both the short- and long-term use of a therapy. It would be irresponsible to suggest that a 21 day study could establish the safety of any drug that is used continually. Further, the safety of interactions between marijuana and other drugs/substances were not established by the study. The use of marijuana in addition to tobacco, for example, is shown to dramatically increase the risk of head and neck cancers. Other research shows that cancer-causing agents in marijuana are much stronger than those found in tobacco. Finally, there is a concern that marijuana bought on the "street" may contain many unknown contaminants, including insecticides or fungus.

The limitations of the current study are well known to researchers at UCSF and they were not responsible for the overstatements made in the media. The group at UCSF plan to develop studies to further assess the safety and utility of marijuana in people living with HIV. For now, the only thing that can be concluded is that short-term marijuana use did not have an effect on HIV levels and that use of either marijuana or dronabinol resulted in greater weight gain than a placebo. This is a far cry from offering proof of the safety of marijuana use. In short, the jury is still out.

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