More states are passing laws that allow people to use medical marijuana. So what does it treat, and who can and should use it?
Pain is the main reason people ask for a prescription, says Barth Wilsey, MD, a pain medicine specialist at the University of California Davis Medical Center. It could be from headaches, a disease like cancer, or a long-term condition, like glaucoma or nerve pain.
An FDA advisory committee recently recommended that the FDA set certain limits on acetaminophen, a drug that is used in many prescription and nonprescription medicines to relieve pain and reduce fever.
Those limits could include taking off the market some prescription drugs, such as the painkillers Percocet and Vicodin, which combine acetaminophen with other active ingredients.
The reason for the proposed limits is the risk of liver damage from taking too much acetaminophen.
If you live in a state where medical marijuana is legal and your doctor thinks it would help, you’ll get a “marijuana card.” You will be put on a list that allows you to buy marijuana from an authorized seller, called a dispensary.
Doctors also may prescribe medical marijuana to treat:
Muscle spasms caused by multiple sclerosis
Nausea from cancer chemotherapy
Poor appetite and weight loss caused by chronic illness, such as HIV, or nerve pain
The FDA has also approved THC, a key ingredient in marijuana, to treat nausea and improve appetite. It's available by prescription Marinol (dronabinol) and Cesamet (nabilone).
How Does It Work?
Your body already makes marijuana-like chemicals that affect pain, inflammation, and many other processes. Marijuana can sometimes help those natural chemicals work better, says Laura Borgelt, PharmD, of the University of Colorado.
How Is It Used?
Medical marijuana may be:
Vaporized (heated until active ingredients are released, but no smoke is formed)
Eaten (usually in the form of cookies or candy)
Taken as a liquid extract
Side effects of marijuana that usually don’t last long can include:
Short-term memory loss
More serious side effects include severe anxiety and psychosis.
Risks and Limits
Medical marijuana is not monitored like FDA-approved medicines. When using it, you don’t know its potential to cause cancer, its purity, potency, or side effects.
Only people who have a card from a doctor should use medical marijuana. Doctors will not prescribe medical marijuana to anyone under 18. Others who should not use it: