Marijuana Health Article

Definition

Marijuana and its medically active components, called cannabinoids, are used in cancer therapy to reduce nausea and vomiting caused by chemotherapeutic medications. This drug, however, is considered an illegal substance in the United States.

Purpose

Marijuana can be used with a variety of cancer chemotherapeutic agents that cause nausea and vomiting. Marijuana seems to work best at preventing nausea and vomiting with mild to moderately active chemotherapeutic agents. There are limited studies showing it does help reduce nausea and vomiting caused by the most powerful cancer chemotheraupeutic drugs. Marijuana may also be used by cancer patients to stimulate appetite.

Description

Marijuana, a plant with known psychoactive properties, has been used by human beings for thousands of years as a medicine. Ancient Chinese writings tell of its use for headaches, menstrual pains, and abdominal distress. It was used in the United States as a medicine for a variety of aliments until 1937, when its use was discouraged by the Marijuana Tax Act, which imposed high taxes on its use. In 1970, it was classified by the U.S. Government as a drug having no known medical use and a high potential for abuse. However, people who use marijuana recreationally have long reported that the drug helped ease nausea and vomiting, leading to its use by cancer patients to help ease the nausea and vomiting brought about by many anti-cancer medications. Because of its illegal status, there are very few well-researched studies examining the effectiveness of marijuana.

When the drug is smoked, it is immediately absorbed into the bloodstream through the rich network of blood vessels in the lungs. Within five to ten minutes the most active chemical part of marijuana, delta-9-THC, reaches the brain, where it produces its anti-nausea and anti-vomiting effects. These effects peak in about one hour, and last for about three hours.

Recommended dosage

Since marijuana is still an illegal drug under federal law, there are no uniform recommended dosages. The amount of delta-9-THC in marijuana determines the strength of the drug, which in turn will affect the amount needed for therapeutic effects.

When marijuana is smoked, the patient can alter the dosage of delta-9-THC simply by altering how much smoke is inhaled, the amount of time taken between inhalations, how deeply the smoke is inhaled, and how long the smoke is held in the lungs. Since the anti-nausea and anti-vomiting effects of marijuana are so rapid in onset, most patients quickly learn how much marijuana they need to smoke to achieve the desired results.

Marijuana can also be taken orally, most commonly either in a tea or baked in cookies. When used this way, the dosage a patient receives is more variable than smoking due to a slower absorption rate in the stomach versus the lungs. A pill containing THC known as dronabinol, is taken as an initial dose of five mg one to two hours before chemotherapy treatment. It can be then taken as five mg every two to four hours after treatment for up to six times a day.

Precautions

The few studies that have examined the safety of marijuana all seem to agree that it is a relatively safe drug. The chances of an overdose appear quite small. However, high doses can lead to tachycardia, or rapid heart rate, in a small percentage of users. Because of this, people with a history of heart problems should only use marijuana under the supervision of a trained health care provider. Since marijuana is also known to cause drowsiness, it should not be used in situations in which people need to remain alert, such as driving. In addition, smoking marijuana increases the risk of lung cancer.