MARIJUANA

What is it?

Marijuana is an herb. It contains chemicals called cannabinoids that affect the central nervous system. Cannabinoids are found in the highest concentration in the leaves and flowers, the parts that are used to make medicine.

Some people use marijuana recreationally to create a sense of well being or to alter the senses. It is either taken by mouth or smoked (inhaled).

Marijuana is also taken by mouth for medicinal purposes. A cannabinoid from marijuana, tetrahydrocannabinol (THC), is used in the prescription-only, FDA-approved product dronabinol (Marinol) for the treatment of weight loss or appetite loss due to AIDS and for nausea and vomiting caused by cancer chemotherapy. Cannabinoids are at least as effective as some conventional medications for nausea, including prochlorperazine (Compazine), metoclopramide (Reglan), chlorpromazine (Compazine), and thiethylperazine (Torecan).

Cannabinoids from marijuana also appear to be similar to codeine for treatment of pain. However, extreme sleepiness and other central nervous system effects make cannabinoids undesirable as painkillers.

Other cannabinoids from marijuana have also been used by mouth to treat symptoms of multiple sclerosis (MS).

Some people inhale marijuana for medicinal purposes. Marijuana is smoked for nausea, glaucoma, appetite stimulation, mucous membrane inflammation, leprosy, fever, dandruff, hemorrhoids, obesity, asthma, urinary tract infections, cough, anorexia associated with weight loss in AIDS patients, pain, and multiple sclerosis. It is also inhaled to weaken the immune system after kidney transplant to lessen the chance of transplant rejection.

Avoid confusion with hemp, a distinct variety of Cannabis sativa cultivated for its fiber and seeds, which contains less than 1% THC.

In the U.S., marijuana is classified as a Schedule I controlled substance, making possession illegal. Some states, such as California, Washington, Oregon, Arizona, and others, have legalized or decriminalized the use of medical marijuana, despite objections from the federal government. Some countries such as Canada also permit the use of medical marijuana.

Is it effective?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for MARIJUANA are as follows:

Possibly Effective for...

Glaucoma. Smoking marijuana seems to reduce pressure inside the eye in people with glaucoma. However, it also seems to decrease blood flow to the optic nerve. So far, it is not known if marijuana can improve sight.
HIV/AIDS-related weight loss. Smoking marijuana seems to stimulate the appetite of people with AIDS. Marijuana cigarettes can also cause weight gain in people with HIV who are also taking indinavir (Crixivan) or nelfinavir (Viracept).
Multiple sclerosis (MS). When smoked or when used as a mouth spray, marijuana seems to be effective for the treatment of muscle tightness and shakiness in people with MS. However, taking marijuana extract by mouth does not seem to consistently reduce shakiness in patients with MS.
Nerve pain. Early research shows that smoking marijuana three times a day might reduce nerve pain caused by HIV and other conditions.
Pain. Research shows that taking marijuana or certain marijuana components, called cannabinoids, by mouth can decrease pain in people experiencing long-term pain.

Insufficient Evidence to Rate Effectiveness for...

Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Early research shows that patients with ALS who use marijuana might have improvements in some symptoms, including depression, appetite, spasms, and drooling.
Weight loss in people with advanced cancer (cachexia). Early research shows that taking marijuana extract by mouth does not improve appetite in people with cachexia.
Rheumatoid arthritis (RA). Some research suggests that using a specific mouth spray containing marijuana extract (Sativex) can decrease morning pain and improve sleep in people with RA. However, it does not seem to improve joint stiffness in the morning or overall pain severity.
Dandruff.
Hemorrhoids.
Obesity.
Asthma.
Urinary infections.
Leprosy.
Preventing organ rejection after kidney transplants.
Other conditions.

More evidence is needed to rate marijuana for these uses.

How does it work?

Marijuana contains chemicals that work by binding to specific sites in the brain and on the nerves.

Are there safety concerns?

The cannabinoid, dronabinol, which is found in marijuana, is LIKELY SAFE when taken by mouth appropriately as a prescription medication. Dronabinol (Marinol) is an FDA-approved prescription product.

Marijuana is POSSIBLY SAFE when used as a standardized mouth spray (Sativex).

Marijuana is POSSIBLY UNSAFE when smoked or taken by mouth as a plant or plant extract. It is classified as an illegal substance on the federal government level.

Use of marijuana can cause dry mouth, nausea, vomiting, dry or red eyes, heart and blood pressure problems, lung problems, impaired mental functioning, headache, dizziness, numbness, panic reactions, hallucinations, flashbacks, depression, and sexual problems.

Special Precautions and Warnings:

Pregnancy: Marijuana is UNSAFE when taken by mouth or smoked during pregnancy. Marijuana passes through the placenta and can slow the growth of the fetus. Marijuana use during pregnancy is also associated with childhood leukemia and abnormalities in the fetus.

Breastfeeding: Using marijuana, either by mouth or by inhalation is LIKELY UNSAFE during breastfeeding. The dronabinol (THC) in marijuana passes into breast milk and extensive marijuana use during breastfeeding may result in slowed development in the baby.

Heart disease: Marijuana might cause rapid heartbeat, short-term high blood pressure. It might also increase the risk of a having heart attack.

A weakened immune system: Cannabinoids in marijuana can weaken the immune system, which might make it more difficult for the body to fight infections.

Lung diseases: Long-term use of marijuana can make lung problems worse. Regular, long-term marijuana use has been associated with lung cancer and also with several cases of an unusual type of emphysema, a lung disease.

Seizure disorders: Marijuana might make seizure disorders worse in some people; in other people it might help to control seizures.

Surgery: Marijuana affects the central nervous system. It might slow the central nervous system too much when combined with anesthesia and other medications during and after surgery. Stop using marijuana at least 2 weeks before a scheduled surgery.