Marijuana

What other names is Marijuana known by?

Anashca, Banji, Bhang, Blunt, Bud, Cannabis, Cannabis sativa, Charas, Dope, Esrar, Gaga, Ganga, Grass, Haschisch, Hash, Hashish, Herbe, Huo Ma Ren, Joint, Kif, Marie-Jeanne, Mariguana, Marijuana Médicale, Marihuana, Mary Jane, Medical Marijuana, Pot, Sawi, Sinsemilla, Weed.

What is Marijuana?

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 of the herb that are used to make medicine.

Some people take marijuana extract by mouth or as a spray to be applied under the tongue for pain and symptoms of multiple sclerosis.

Some people inhale marijuana for medicinal purposes. Marijuana is smoked for nausea, glaucoma, appetite stimulation, to reduce swelling of mucous membranes, for leprosy, fever, dandruff, hemorrhoids, obesity, asthma, urinary tract infections, cough, anorexia associated with weight loss in AIDS patients, nerve pain, and multiple sclerosis. It is also inhaled to weaken the immune system after kidney transplant to lessen the chance of transplant rejection. In addition, marijuana is smoked to reduce symptoms amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease).

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).

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.

Possibly Effective for...

  • 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). Applying a specific spray containing marijuana extract (Sativex, GW Pharmaceuticals) under the tongue seems to improve some self-reported symptoms of multiple sclerosis, including muscle spasms, need to urinate, and nerve pain. In the UK, this product is approved as a prescription medicine to treat muscle spasms in people with MS. In Canada, this product is approved to treat nerve pain in people with MS. This product is not available as a prescription medicine in the US. Also, some conflicting evidence suggests that this product does not significantly improve muscle spasms, nor does it reduce the need to urinate or tremors in MS patients. There are conflicting results regarding the effects of marijuana extract when taken by mouth. One small study shows that taking a specific marijuana extract (Cannador, Society for Clinical Research) by mouth reduces self-reported muscle stiffness and muscle spasms in people with MS. However, other studies show that taking marijuana extract by mouth does not significantly improve muscle spasms, the ability to walk, or tremors in people with MS. Early research shows that smoking marijuana may reduce muscle spasms, pain in the arms and legs, and tremors in people with MS.
  • Nerve pain. Early research shows that smoking marijuana three times a day might reduce nerve pain caused by HIV and other conditions.

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.
  • Glaucoma. Smoking marijuana seems to reduce pressure inside the eye in people with glaucoma. However, this effect seems to last for only 3-4 hours. Also, smoking marijuana seems to decrease blood flow to the nerve that transmits visual information from the eye to the brain. This might increase vision loss in people with glaucoma. So far, it is not known if marijuana can improve sight in people with glaucoma.
  • Rheumatoid arthritis (RA). Some research suggests that using a specific mouth spray containing marijuana extract (Sativex, GW Pharmaceuticals) 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.
  • Asthma.
  • Dandruff.
  • Hemorrhoids.
  • Leprosy.
  • Obesity.
  • Preventing organ rejection after kidney transplants.
  • Schizophrenia.
  • Urinary infections.
  • Other conditions.
More evidence is needed to rate marijuana for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

How does Marijuana work?

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

Are there safety concerns?

Marijuana extract is POSSIBLY SAFE when used as a standardized spray (Sativex, GW Pharmaceuticals) that is applied under the tongue.

Marijuana is POSSIBLY UNSAFE when smoked. Smoking marijuana is associated with an increased the risk of developing lung cancer. Also, some reports suggest that smoking marijuana might cause air-filled cavities to form within lung tissue. These air-filled cavities can cause symptoms such as chest pressure, soreness, and difficulty breathing.

Smoking marijuana or using mouth sprays containing marijuana extract can cause headache, dizziness, drowsiness, dry mouth, nausea, and paranoid thinking. Smoking marijuana might also increase appetite, cause coughs, increase heart rate, increase or decrease blood pressure, and impair mental functioning. Some reports suggest that smoking marijuana may also increase the risk of acute coronary syndrome, heart attack, and/or swelling of walls of the arteries (arteritis). However, in many cases, people who experienced these events after smoking marijuana had other risk factors for heart-related events such as smoking cigarettes or being overweight.

Special Precautions & 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.

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

Bipolar disorder: Using marijuana might worsen manic symptoms in people with bipolar disorder.

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.

Depression: Marijuana use, especially frequent use, might worsen symptoms of depression.

Multiple sclerosis: Taking marijuana by mouth might worsen some symptoms of multiple sclerosis.

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.

Schizophrenia: Using marijuana might worsen symptoms of schizophrenia.

Stroke: Using marijuana after having a stroke might increase the risk of having a second stroke.

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.

Are there any interactions with medications?



Antipyrine
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

The body breaks down antipyrine to get rid of it. Some chemicals in marijuana might decrease how quickly the body breaks down antipyrine. This might increase antipyrine levels in the body and increase its effects and side effects.



Disulfiram (Antabuse)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Taking marijuana with disulfiram (Antabuse) might cause you to feel irritated, nervous, jittery, and excited. Doctors call this hypomania.



Fluoxetine (Prozac)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Taking marijuana with fluoxetine (Prozac) might cause you to feel irritated, nervous, jittery, and excited. Doctors call this hypomania.



Medications changed by the liver (Cytochrome P450 2E1 (CYP2E1) substrates)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Some medications are changed and broken down by the liver. Marijuana might increase how quickly the liver breaks down some medications. Using marijuana along with some medications that are broken down by the liver might decrease the effects of some medications. Before using marijuana talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications changed by the liver include acetaminophen, chlorzoxazone (Parafon Forte), ethanol, theophylline, and anesthetics such as enflurane (Ethrane), halothane (Fluothane), isoflurane (Forane), methoxyflurane (Penthrane).



Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Some medications are changed and broken down by the liver. Marijuana might decrease how quickly the liver breaks down some medications. Using marijuana along with some medications that are broken down by the liver might increase the effects and side effects of some medications. Before using marijuana talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications changed by liver include lovastatin (Mevacor), clarithromycin (Biaxin), cyclosporine (Neoral, Sandimmune), diltiazem (Cardizem), estrogens, indinavir (Crixivan), triazolam (Halcion), and others.



Medications moved by pumps in cells (P-glycoprotein Substrates)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Some medications are moved by pumps into cells. Marijuana might make these pumps less active and increase how much of some medications get absorbed by the body. This might increase the side effects of some medications.

Some medications that are moved by these pumps include etoposide, paclitaxel, vinblastine, vincristine, vindesine, ketoconazole, itraconazole, amprenavir, indinavir, nelfinavir, saquinavir, cimetidine, ranitidine, diltiazem, verapamil, corticosteroids, erythromycin, cisapride (Propulsid), fexofenadine (Allegra), cyclosporine, loperamide (Imodium), quinidine, and others.



Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Marijuana might slow blood clotting. Taking marijuana extracts along with medications that also slow clotting might increase the chances of bruising and bleeding.

Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.



Sedative medications (Barbiturates)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Marijuana might cause sleepiness and drowsiness. Medications that cause sleepiness are called sedatives. Taking marijuana along with sedative medications might cause too much sleepiness.



Sedative medications (CNS depressants)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Marijuana might cause sleepiness and drowsiness. Medications that cause sleepiness are called sedatives. Taking marijuana along with sedative medications might cause too much sleepiness.

Some sedative medications include clonazepam (Klonopin), lorazepam (Ativan), phenobarbital (Donnatal), zolpidem (Ambien), and others.



Theophylline
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Taking marijuana might decrease the effects of theophylline. But there isn't enough information to know if this is a big concern.



Warfarin (Coumadin)
Interaction Rating: Minor Be cautious with this combination.
Talk with your health provider.

Using marijuana might increase the effects of warfarin (Coumadin). Smoking marijuana while taking warfarin (Coumadin) might increase the chance of bruising and bleeding.

Dosing considerations for Marijuana.

The following doses have been studied in scientific research:

BY MOUTH:
  • For multiple sclerosis: One to five capsules containing marijuana extract standardized to contain tetrahydrocannabinol 2.5 mg and cannabinol 0.8 to 1.8 mg (Cannador, Society for Clinical Research, Berlin, Germany) has been taken twice daily for 12 weeks.
AS A MOUTH SPRAY:
  • For multiple sclerosis: A specific marijuana extract product (Sativex, GW Pharmaceuticals, Salisbury, UK), standardized to contain 2.7 mg of tetrahydrocannabinol (THC) and 2.5 mg of cannabidiol per spray, has been used daily for up to 2 years.
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Reviewed on 3/29/2011 12:35:40 PM

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